Table of Contents

Sierra Nevada Bio-region
Chapter 1: Ecological Integrity of Ecosystems - Terrestrial Ecosystems

Current Condition

Introduction

A rich diversity of ecosystems are found in the Sierra Nevada bio-region because of the diverse climate and topography, as well as juxtaposition of several regional floras (Minich 2007). To the north, it is influenced by the Great Basin, Cascade Range and Klamath Mountains. To the west, the Great Valley of California, and to the east the Great Basin and Mojave Desert intergrade with the bio-regional analysis area. To the south are the mountain ranges of southern California. Within the Sierra Nevada, there is great diversity of elevations and precipitation patterns, as well as geology. About 50% of California’s 7,000 plant species occur in the Sierra Nevada (Shevock 1996). Four hundred of these species occur only in the Sierra Nevada, they are endemic. Similarly, 60% of the state’s animals (including mammals, birds, reptiles, and amphibians) occur in the bio-region (Graber 1996).

Characterizing ecosystems is like painting a landscape. Each different artist may paint the landscape differently, using different color schemes and levels of detail, but it is still the same landscape. Similarly, the terrestrial ecosystems of the bio-region can be looked at with a “broad brush” or with fine detail. In this assessment, for the most part, the broad brush approach or “coarse-filter” approach is appropriate, since the area is so large and ecosystems so diverse. In some instances, certain ecosystems warrant more detailed attention because of their rarity and significance to ecosystem function or human values. These include, but should not be limited to, aspen communities and giant sequoia forests.

Using a coarse-filter approach, the vegetation types or habitat types, are a useful way to describe the current condition and trends, and integrity of ecosystems. This means that instead of trying to catalog and assess the condition of all of the individual species and locations, the forests or chaparral they live in is assessed. Another important coarse filter approach is to examine key changes that affect vegetation or habitat types. In the Sierra Nevada, fire is potent force that can change vegetation or habitat types. There are some elements of habitat that are critical to numerous species and occur throughout different vegetation types.

However, in PSW-GTR-237, Managing Sierra Nevada Forests (2012) authors Malcolm North and Patricia Manley suggest that “coarse filter” approaches such as the California Wildlife-Habitat Relations model “generally fail to account for the different spatial and temporal scales at which species may respond to forest conditions or assess habitat features other than large trees and canopy cover.”

The issue of simplification of forest ecosystems is at the heart of the issue of loss of biodiversity: they are two sides of the same coin. It can be summed up this way, quoting from the 1996 Sierra Nevada Ecosystem Project: "The primary impact of 150 years of forestry on middle-elevation conifer forests has been to simplify structure (including large trees, snags, woody debris of large diameter, canopies of multiple heights and closures, and complex spatial mosaics of vegetation), and presumably function, of these forests" (SNEP 1996, Summary, p. 6).

Legacy structures and species disappear as forests become more homogenized or simplified. These include snags, or standing dead trees, down wood, and old-growth trees with complex features like cavities, chambers, and mistletoe brooms. Many of these structures are unique and may take many decades to develop; other biological features associated with old forest include mycorrhizal symbionts and old-growth associated fungi, lichens, and terrestrial orchids. Together with the many important elements of the early forest types, and diverse geomorphic and other abiotic features, unique niches are formed that give rise to the rich biological diversity that characterizes the Sierra Nevada region.

Other features that comprise the forest diversity landscape that are not captured in a broad brush, or coarse filter approach, are rock outcrops, small meadows, seeps and springs; unique hardwood stands, and certain types of chaparral.

Salvage logging is particularly detrimental to forest biodiversity, erasing not only the post-fire structure but also skipping the "forgotten stage of forest succession" (Swanson et al 2010). Forest types that are allowed to naturally regenerate after fire without interference (eg salvage logging/planting/herbicides) are now among the rarest type of forest ecosystem in western forests (see for example, comments in attached PDF, J. Franklin, Biscuit Fire DEIS, 2004) The degree to which natural forest stands are converted to homogenous conifer tree plantations is a significant metric contributing to simplification, or biodiversity loss, and uncharacteristic fire behavior. See Franklin and Agee 2003: "In many areas throughout western North America, uncharacteristic stand-replacement wildfires have been followed by reforestation programs that recreate the dense young forests, providing the potential for yet another stand-replacement fires." Also see attached PDF file:

References for issues on salvage logging and simplification
  • Lindenmayer, D.B., P. Burton, and J. Franklin. 2008. Salvage Logging and its Ecological Consequences. Island Press.
  • Mitchell, R.J.; Franklin, J.F.; Palik, B.; et al. 2003. Natural disturbance-based silviculture for restoration and maintenance of biological diversity. In: Final report to the National Commission on Science for Sustainable Forestry.
  • Sierra Nevada Ecosystem Project: Final Report to Congress. Davis: University of California, Centers for Water and Wildland Resources, 1996.

It is theoretically possible to miss most of the factors contributing to loss of biological diversity at the landscape scale through the use of inadequate habitat modeling devices such as the CWHR or similar conifer-centric habitat models. For a comprehensive literature review of the broad brush/fine grain issues, see the list of references below.

References for Wildlife Monitoring: Coarse Grain versus Fine Grain Issues
  • Biber, E. 2011. The problem of environmental monitoring. University of Colorado Law Review, 83:1, 2011.
  • Committee of Scientists on the internet at http://www.fs.fed.us/news/news_archived/science/
  • Cushman, S.A., K.S. McKelvey, C.H. Flather, and K. McGarigal. 2008. Do forest community types provide a sufficient basis to evaluate biological diversity? Frontiers in Ecology and the Environment 6:13-17.
  • Cushman, S.A., K.S. McKelvey, B.R. Noon, and K. McGarigal. 2010. Use of abundance of one species as a surrogate for abundance of others. Conservation Biology 24:830-840.
  • Schultz, C.A., T.D. Sisk, B.R. Noon, and M.A. Nie. 2012.Wildlife conservation planning under the United States Forest Service's 2012 planning rule. The Journal of Wildlife Management. doi: 10.1002/jwmg.513
  • Flather, C.H., K.R. Wilson, and S.A. Shriner. 2009. Geographic approaches to biodiversity conservation: implication of scale and error to landscape planning. Pages 85-12 in J.J. Millspaugh and F.R. Thompson, III, editors. Models for Planning Wildlife Conservation in Large Landscapes. Academic Press, New York.
  • Keane, J. J. 2013. 2013. California spotted owl: scientific considerations for forest planning. Pages 302-325 in Science Synthesis to support Forest Plan Revision in the Sierra Nevada and Southern Cascades. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 504 p.
  • Noon, B.R., K.S. McKelvey, and B.G. Dickson. 2009. Multispecies conservation planning on U.S. federal lands. Pages 51-84 in J.J. Millspaugh and F.R. Thompson, III, editors. Models for Planning Wildlife Conservation in Large Landscapes. Academic Press, New York.
  • North, M. and P. Manley. 2012. Managing forests for wildlife communities. Pages 73-80 in North, Malcolm, ed. 2012. Managing Sierra Nevada Forests. Gen. Tech. Rep. PSW-GTR-237. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 184 p.
  • Schlossberg, S. and D.I. King. 2009. Modeling animal habitats based on cover types: a critical review. Environmental Management 43:609-618.

Recently, Swanson et al (2010) have initiated the correct forestry science conversation needed to accurately describe the status of forests that have been managed under an intensive agriculture model for a century. Armed with this knowledge, in this assessment we will now include plantation data as a discrete field rather than a proxy for early natural forest stands.

There are also some individual species, usually those that are wider ranging and carnivores that provide good representatives to assess whether species can move readily across the landscape. The Pacific Fisher and California spotted owl are two such species.

Other habitat types support distinct species communities and the ecological integrity of these habitats can be effectively assessed using groups of species, such as birds. Partners in Flight and other conservation groups have developed habitat-specific focal species monitoring and management plans (Chase and Geupel 2005, Wiens et al. 2008) that describe the species best suited for monitoring and assessing the integrity of a large variety of habitats. Lists and descriptions of these focal species can be viewed here: http://www.prbo.org/calpif/data.html, and include plans focused on coniferous forest, riparian and other habitats, as well as a conservation plan for the entire Sierra Nevada (Siegel and DeSante 1999).

This assessment is purposely a compilation of readily available, existing information. There are several primary sources of information on vegetation and habitat types in California. First, is the existing vegetation layer (EVEG) that is developed across all lands by the US Forest Service in coordination with FRAP. Second, the national FIA plots that are laid out on a systematic grid are available. These were the two primary sources of information for this assessment. Fire as a process, is described in more detail in the Drivers and Stressors Chapter, but information from that section is utilized here. Information on connectivity associated with the California spotted owl and forest carnivores are available in databases that the state of California and the US Forest Service maintain, as well as with scientific projects including those of the Center for Biological Diversity, university and agency researchers and others described in the sections on these indicators of connectivity below. For a wider group of birds, occurrence data are widely available from throughout the Sierra Nevada National Forests through an ongoing monitoring program on forest chaparral, and riparian habitats, plus an associated data base and interactive web-based tool (the Sierra Nevada Avian Monitoring Information Network, http://data.prbo.org/apps/snamin/) that can assist current planning efforts and assess management actions on ecosystem integrity now and into the future.

Conditions related to function/services

Ecological integrity can be characterized in countless ways. In the chapter introduction, the complementary concepts of using natural range of variability and indicators related to ecosystem services were described. The natural range of variability assessment is in progress and will be incorporated in the next phase when trends are incorporated. The measures for ecological integrity that are described here include both those that will be incorporated into the natural range of variability assessment, as well as those that are not feasible to be addressed in this way (i.e. owl populations). In order to make the assessment meaningful and “doable” the focus was on those conditions that are the focus of ecosystem services and with available interpretations.

Key Ecological Integrity Characteristics/Measures


A conceptual model of how key components and processes of terrestrial ecosystems interact was utilized to frame which indicators were important to assess. This is an approach recommended by Noon (2003) to develop ecosystem monitoring indicators. In adaptive management, there is a continual iteration of assessment, monitoring, and planning. It makes sense to apply the same conceptual model to the assessment as the monitoring phase. The intent was to develop a framework that is concise, and not overly complex, which highlights the most important conditions and processes that influence ecosystem function and services. Numerous conceptual models could be derived, and this one is meant to be simple, doable and based upon the history of management issues and concerns in the bio-region.

Selection of indicators and measures was based on a conceptual model framework (see figure below for terrestrial ecosystem) as recommended by Noon (2003).The interactions of processes and components of ecosystems across the landscape were considered and the processes that strongly influence ecosystem functioning, sustainability and resilience were selected. For example, fire is a key ecological process that shaped terrestrial and riparian ecosystems in the bio-region (van Wagtendonk and Fites-Kaufman 2006).

Characterizing ecosystems is like painting a landscape; each artist may paint the landscape differently. Similarly, the ecosystems of the bio-region can be looked at with a “broad brush” or with fine detail. In this assessment, the broad brush approach or “coarse-filter” approach is applied across a broad landscape. Rare ecosystems with great significance such as aspen or giant sequoia forests will be considered. North and Manley (2012) suggest that “coarse filter” approaches “fail to account for the different spatial and temporal scales at which species may respond to forest conditions “. Many of the over 900 potential species of concern are endemic and have limited distributions (Chapter 5, WIKI). Since this is a regional and landscape level assessment we will not use a fine filter for most species. However, the conceptual aspect of focal species that may be in common across the bioregion is important (Schultz et al. 2013) to ensure that the assessment assembles existing information on species that may be important for impact analysis in the forest plans.

Ch1_Terrestrial_Eco_Influences_Dynamics.jpg
Conceptual Model Framework indicating key pathways among the ecological elements considered, and drivers and stressors.


Figure: Conceptual Model Framework indicating key pathways among the ecological elements considered, and drivers and stressors.

Biodiversity, living organisms, plants, mammals, birds, insects, fungi, even bacteria, and the unique communities they occur in, are integral components of ecosystems. Their integrity is central to overall ecosystem integrity, which also includes the non-living parts (e.g. air, rocks, water) and the processes that link them together such as carbon cycling. It is a monumental task to assess all aspects of biodiversity. The planning rule addresses two levels of biodiversity: coarse-filter and fine-filter. The draft planning directives provide further direction on coarse-filter and fine-filter elements to address. We have included coarse-filter, fine-filter, and intermediate filter-levels for this assessment. For some characteristics, such as connectivity of old forest, we have integrated both coarse-filter and fine-filter aspects. For example, connectivity of old forest is measured using habitat and distribution for spotted owls and forest carnivores (fisher and pine marten) that serves as both a coarse-filter, landscape measure as well as fine-filter since spotted owls and forest carnivores serve as examples of potential “focal species” as top food-chain (carnivore) species that are often sensitive to environmental changes from large fires, or land-use.

The table below illustrates using the conceptual framework; a combination of available coarse, intermediate and fine filters, existing information; the following set of measures were selected to focus the assessment. Larger scale conditions and processes such as habitat patterns, connectivity for limited habitat types (old forest and early seral, especially recently burned) and wide-ranging species, respond to ecosystem processes.


Ecological element
Measure
Source
Fine Filter
Species Presence? important for TES
Species distribution, condition, and threats
Species of concern assessment (Chapter 5 WIKI)
Focal Species
Conceptual model
Scientific literature (i.e. Shultz et al. 2013)
Avian focal species abundance and composition
California partners in flight habitat conservation plan focal species group abundance
http://www.prbo.org/calpif/data.html

http://data.prbo.org/apps/snamin/ by
Coarse Filter
all species (coarse-filter biodiversity); amount and distribution of habitat types
% of landscape by California Wildlife Habitat Relationship Types
US Forest Service Remote Sensing Lab existing vegetation maps, and FRAP maps
Distribution of limited habitat types
aspen, oak/hardwood, burned forest, giant sequoia, bristlecone pine, sagebrush, meadows, montane chaparral
RSL/FRAP/fire severity maps
Connectivity of old-forest species (coarse filter) habitat and geneflow potential
old forest amount, patch size, distribution, distribution of sage grouse, goshawk, spotted owl, fisher and pine marten.
Spencer et al. 2012; Franklin and Fites-Kaufman 1996; Natural Resource Information System, California Fish and Wildlife Dept. and US Fish and Wildlife
Connectivity of early seral and non-forest patches.
early forest amount, distribution and type;
USFS Remote Sensing Lab existing vegetation and Fire Severity Monitoring Program Data.
Fire as an ecological process: (1) regulate carbon and (2) fire resiliency, (3) creates or enhance habitat for fire dependent species, and (4) enhanced flora and fauna diversity.
Proportion of landscape burned at different fire severity levels (composite burn index); Fire return interval departure; Fire resilience
R5 Fire Severity Monitoring Program; Safford and xxxx, Chapter 1 and 3 WIKI, literature
Process: vegetation growth (succession) carbon cycling, nutrient cycling, productivity
Changes in above ground biomass, and live and dead vegetative carbon. Net decomposition.
FIA plots, changes over time in biomass and litter and woody cover.
Intermediate Filter
plant diversity; animal; fungi; invertebrate; other lifeform diversity :
amount and distribution of microhabitats, within patch diversity/heterogeneity
GTR-237; FIA plots – within plot variability of canopy cover, tree density, shrub cover, gaps
Dead wood habitat : Snags, coarse woody debris
tons/acre, density by size and decay class
FIA plots
Tree composition: relative density of functional groups (hardwoods, pines, shade tolerant)
tree density by species and layer
FIA plots
Process: old forest dynamics. large tree recruitment and mortality
Density of medium and large diameter trees; % mortality by diameter by species? By year
FIA (existing analysis), GTR-237 by subregion, ecological zone, vegetation type

Selected key ecological integrity indicators/measures are focused on:
  • broad scale, or “coarse-filter” patterns in vegetation composition and structure,
  • connectivity and habitat for wide-ranging carnivores (fisher, marten, California spotted owl and goshawk), *any shrub equivalent? suggest we use sage grouse for sagebrush
  • habitat elements that are important to many biota (i.e. snags and large trees) and may be limited in areas, *others may include cavity trees; willow cover in meadows
  • habitat conditions that have been altered by management in the last 100 years (e.g. suppression of fire as a process), such as within-patch heterogeneity or variation in vegetation structure and composition
  • habitat diversity important for specific groups of plants and animals.
  • California Partners in Flight habitat conservation plan focal species abundance
  • Biodiversity as reflected in multi-species (avian, invertebrates, mammalian, herps, or other) indices such as: richness, Shannon-Wiener/Simpson/other diversity metrics, and other measures including genetic markers
  • Ecological Groups, Guilds or Assemblages that provide an intermediate level between very broad coarse-filter measures and individual species as components of ecological integrity. Specifically, these allow an intermediate measure of ecological integrity centering on biodiversity. It is particularly useful in relevant assessment of species of concern as well as common or ecologically significant species such as "ecosystem engineers".


Current Condition


Ecological Integrity – Natural Range Of Variability Of Vegetation, Fire, Insects/Pathogens

A primary assumption of the new planning rule is that “natural range of variability” is a key means for gauging ecological integrity. This is based upon extensive scientific writing on the subject. The main ideas is that efforts to achieve ecosystem sustainability and persistence are likely to be more successful if they maintain ecosystems within the bounds of natural variation (NRV) rather than targeting fixed conditions from some point in the past, such as historic conditions (Wiens et al. 2012). Safford et al. (2013) compiled comprehensive, scientific literature reviews on NRV, with only key points summarized here.

The foothill ecological zone occurs at the lowest elevations, comprised of chaparral, blue oak savannahs, live oak woodlands and forests, narrow riparian stringers along rivers and streams, seeps, and scattered gray pine or occasional patches of knobcone pine (Barbour and Schroer 2007). Overall, the vegetation and fire patterns in this zone are outside of the range of variability (Estes 2013, Merriam 2013, and Sawyer 2013). The foothill zone is amongst the most altered, and fragmented by land-use (urbanization and agricultural conversion) and mostly below the western boundaries of national forests (Sierra Conservancy 2011). Vegetation is mostly out of NRV with persistent nonnative species, urbanization, water development, changed fire regime, and agricultural uses as the primary causes.

Ponderosa pine, black oak, mixed conifer, riparian forests and to a lesser extent chaparral and meadows comprise the vegetation mosaic in the westside montane zone (Fites-Kaufman et al. 2007), and occupy the greatest extent in the bioregion (7.5 million acres including eastside types and upper montane Jeffrey pine). Composition, structure, and fire regimes have changed considerably since presettlement times and are largely outside of NRV (Safford 2013, Merriam 2013). Pines and oaks have decreased substantially and shade tolerant species (cedar and fir) have increased. Forest density is higher, canopy cover of trees more uniformly higher, small and medium tree density is higher and large tree density is lower. Within stand variation (heterogeneity) in tree sizes and density is decreased. Climate has been wetter, with fewer droughts in the late 19th and 20th centuries than earlier periods (Safford 2013). This means that pre-settlement forest conditions may not reflect what will be resilient forests in the near future with projected drying, and warming climate. Fires are less frequent but there is some evidence that they are larger, or certainly more severe in large uniform areas, than presettlement. Changes in fire have contributed to contractions of interspersed chaparral patches (Estes 2013a), and black oak patches and trees (Merriam 2013). Overall resilience of the forests to drought and fire has changed considerably (Safford 2013). Increases in chaparral and hardwood vegetation will most likely occur at lower reaches of the zone. Some evidence exists that this has already occurred in steep, river canyons in the southern Sierra Nevada (Kern and King River canyons), in the central area (Merced, Tuolumne and Stanislaus River canyons), and is now progressing north into the Feather River Canyon. The forest zone gets pushed up, compared to where it could grow (Sugihara, personal communication 2013). Giant Sequoia (National Parks, Tahoe, Stanislaus, Sierra and Sequoia National Forests) is particularly vulnerable to climate change, with wetter areas it depends upon expected to shrink (York et al. 2013 and Giant Sequoia National Monument Plan).

Red fir forests, Jeffrey pine woodlands, lodgepole pine forests, meadows, alder patches, herbaceous patches and chaparral create a diverse mosaic in the upper montane ecological zone (Fites-Kaufman et al. 2007). Red fir forests are both within and without NRV (Meyer 2013a) and are amongst the most vulnerable to climate change (NPS 2013, TACCIMO 2013). Structure has shifted with homogenization at stand and landscape scales, increases in small and medium trees, and decreases in large trees. Fire return intervals have lengthened but total area burned has increased since 1984. Recent increases in mortality associated with moisture stress, insects and pathogens suggest that they may move outside NRV soon. Up to an 80% loss of red fir is projected with snowpack declines, which is already declining and expected to decline more with climate change. Aspen and meadows are occur in wetter areas and are particularly rich in plant and animal diversity (Estes 2013b). Some aspects of aspen are within NRV and many outside of NRV. Plant composition and diversity appear to be largely within NRV but extent has contracted and fragmented. Grazing, water development and fire suppression have had various effects on composition, structure, and distribution. Regeneration and structural diversity have declined. Meadows and riparian communities are both within and outside of NRV. Very little scientific information on NRV for meadows exists (Gross and Coppoletta 2013). Early extensive grazing prior to 1930 was intense and concentrated in meadows, along with other land-uses resulted in a large number of incised stream channels, reducing small flood events and wetland species. Species composition has also shifted outside of NRV where nonnative invasive species have been introduced (e.g. dandelion). Fire suppression has contributed to conifer invasion on meadow edges, but there is uncertainty how much of the invasions are related to periodic, long-term fluctuations in climate. Current livestock grazing levels are considerably lower, with overall biomass of most meadows within NRV. Meadows are vulnerable to climate change (Hopkinson et al. 2013). As with meadows and aspen, there is limited scientific information on NRV of chaparral in upper montane landscapes (Estes 2013a and Meyer 2013). Changes in fire regime from suppression and land-use have decreased shrub patches but composition is thought to be within the NRV.

Subalpine forests are largely within NRV (Meyer 2013). There have been some shifts in structure toward higher density stands and a decrease in large diameter pines due to climate warming and and logging in the 19th century. Fire return intervals have lengthened but total area burned has increased in some types since 1984. Overall fire regimes are within NRV at this time but with climatic change are projected to increase in frequency, area burned and severity. Increased mortality of western white pine from white pine blister rust has occurred but otherwise mountain pine better outbreaks have likely not changed. There has been an upward migration of some species into alpine zones, and growth, such as bristlecone pine, beyond the natural range of variability, likely due to increased temperature. Subalpine forests are considered vulnerable to climate change (Eschtruth et al. 2013; TACCIMO 2013) and are projected to decrease by up to 85% or more by the end of the century.

Eastside yellow pine and mixed conifer forests are in similar condition to westside montane pine and mixed conifer forests (Safford 2013). Structure and fire regimes outside of NRV, with denser trees, more uniform forests, and larger, higher intensity fires. The 2012 Barry Point fire that burned 93,000 acres in Modoc County and into Oregon (http://www.inciweb.org/incident/3105/) is an example. While frequent fires were once common place in the dry, flatter, lightening prone landscapes common east of the Sierra Nevada and southern Cascades, rarely were they so uniformly intense. Plant composition has changed, but most species are still present. There has been a large departure in vegetation from invasive plants, especially cheatgrass which has become established across large swaths.

Pinyon-Juniper woodlands and sagebrush are prevalent across the eastern portion of the bioregion, dominating where it is driest (Slayton 2013a, b). There are aspects of these types that are in NRV and others that are far outside of NR. Research on some aspects is extensive (pinyon-juniper invasion and cheatgrass) but there are many uncertainties in other aspects. Current patch structure and composition are within NRV but landscape patterns are not. Early seral habitat is lower, non-native cheatgrass has displaced native plants and entire patches of sagebrush, and pinyon-juniper has increased. Fire regimes are partially outside of NRV, with less frequent fires in some areas, and more frequent fires where cheatgrass has invaded. Desert species are encroaching from the south, and with climate change fire activity will increase. Pinyon-juniper has always migrated with climate change, but fire suppression and grazing have enhanced the process, expanding the distribution recently. Stands on sites with shallow soils remain stable, but on other sites climate change will increase fire, and increase cheatgrass invasion.

Vegetation Dynamics And Carbon Cycling Processes

Just like people, families and communities, forests, shrublands, and grasslands grow over time, and change in size, numbers and mixtures. In ecological terms, this is “vegetation dynamics” or succession. An important aspect of vegetation dynamics is how carbon balances or flows through ecosystems, or carbon cycling. Extracting oil to use in cars and industry, with some that is emitted back to the atmosphere and affects global weather is one example. With natural ecosystems, plants and fires play important roles. Plants use carbon dioxide from the air in photosynthesis to build sugar, and grow. When they die and break down (decompose) or burn, they release carbon dioxide back to the air. Equally important or more important in dry, fire prone ecosystems than uptake or “sequestration” of carbon by growing plants, is the resiliency of forests to intense fires which release vast amounts of carbon rapidly into the air. In this section, we consider the changes or dynamics of vegetation growth and density, and implications for carbon cycling, key aspects of resiliency, sustainability and ecological integrity of ecosystems, based primarily upon the 2013 science synthesis (North Chapter 2, Collins and Skinner Chapter 4.1, Moghaddas Chapter 5), topical papers for the bioregional assessment (Chapter 1, 3, 4, 8, WIKI), and other key recent research papers.

A large portion of the bioregion, the montane pine and mixed conifer forests, are relatively productive in terms of vegetation growth but because they are dry, decomposition or breakdown is slow. This means that dead plant material continues to accumulate over time in the absence of fire (Stephens et al. 2012). Re-measurement of permanent Forest Inventory Plots (FIA) show consistent increase in tree biomass (measure of growth) alone that exceeds removal from decomposition, fire, or thinning by a significant margin (Chapter 3, WIKI; USFS Westcore Tables 2012; Fried personal communication). This results in increasing fuels for fire and likelihood of high intensity crown fires (Stephens et al. 2012) and likelihood of widespread insect outbreak (Sierra Conservancy 2012a) beyond NRV levels (Chapter 3, WIKI).

Fire played an important role as an ecosystem process in “regulating” forest structure and density (Collins and Skinner 2013: Science Synthesis Chapter 4.1). Previously, attention was focused on sequestration of carbon from younger, fast growing trees but newer studies found that old forests and large trees continue to sequester carbon and store more carbon than younger stands (North 2013: Science Synthesis Chapter 2). The concept of carbon carrying capacity (Keith et al. 2009) emphasizes carbon stability and is particularly relevant in dry, fire prone forests, such as in the bioregion. Historical forests may have been less dense, but stored more carbon in the higher numbers of large trees (North 2013: Chapter 2 Science Synthesis).

Offsets to reduced future wildfire carbon emissions from treatments (mechanical, prescribed and managed fire) has been debated in the relative tradeoffs (North 2013). These are based largely on uncertainties with smoke emissions (Bytnerowicz et al. 2013: Science Synthesis Chapter 8) and carbon cycling estimates. Recent research from long-term plots in areas treated with prescribed fire and thinning to reduce fuels in the bioregion have demonstrated that there is a significant offset in potential emissions from high intensity wildfires that last at least 8 years (Vaillant et al. 2013). This corroborates findings from more localized areas (Hurteau and North 2010) and other areas (Boerner et al. 2008, Hurteau et al. 2011). But with less intensive treatment the recovery is faster (Vaillant et al. 2013).

The rate of vegetation change and carbon dynamics is a vital consideration with restoration. One restoration treatment entry is ever sufficient. The rate of vegetation response can yield positive and negative ecological integrity outcomes. Vaillant et al. (2013) found that understory shrub cover recovered within 5 to 8 years of both burning and thinning in monitoring plots in the bioregion—important habitat components for many birds, small mammals and their food and “housing” requirements (leaves, fruits, branches, and insects). In turn, these smaller animals are important prey for predators, often of concern, including owls and goshawks. But tree seedlings also rapidly recover and the cycle of increased forest density goes on. Thinning may not sufficiently reduce surface or ground fuels to change fire intensity (Vaillant et al. 2013) to desired levels, and may need follow up prescribed fire.

Vegetation Conditions – Coarse Filter

Vegetation structure and composition at the broad scale are represented here by the California Wildlife Habitat Relationships (CWHR) types. These are broad categories of habitat based upon dominant plant species, density (usually canopy cover), and average size of trees or shrubs. In the case of trees, it is the average diameter of trees. This is a classification that has been widely used by California state agencies and federal agencies such as the Forest Service. For individual wildlife or plant species of interest, these types may not always characterize the habitat as specifically as current science identifies (North 2012-GTR 237), it is the best available vegetation information that encompasses the entire area. It does provide a reasonable “coarse”, big picture view of vegetation condition.


For the purposes of this assessment, some of the categories of vegetation were combined to make it useful. For example, Jeffrey pine and ponderosa pine cover types were combined into a single yellow pine cover type. Another example is collapsing of seedling and sapling tree size classes into one young size class. The ways these categories were combined is detailed in the appendix.

These methods do not incorporate the use of a necessary new habitat category, the agriculture/plantation category. This category is necessary to accurately distinguish between natural forest development in the region, and agricultural tree cropping systems. It is no longer acceptable to merge most plantation acres with conifer age classes, particularly where these resulted from standard methods of salvage logging, planting, and herbicide use. See Mitchell et al 2003, Franklin and Agee, Lindenmayer et al 2008, and Swanson et al 2010, as referenced above.

Plantation acres will not contribute either early successional or late successional attributes to the bioregion within the foreseeable future on private industrial timberlands and FS lands where prior management emphasized homogenous conifer plantings over natural succession and native plant diversity. It’s important to note what percentage of the landscape is in that condition in this assessment.

Depictions of broad vegetation patterns, including lifeforms (forest, shrub, grassland etc), density (canopy cover), and average size (tree diameter) were summarized from the Existing Vegetation map layers developed by the US Forest Service Remote sensing lab. These maps are developed using a combination of remote sensing data (from LANDSAT satellite images) and field plot data (xxxxx). They cover all lands and are available on xxxxx website. They are periodically updated, approximately every five years, with new satellite images and maps of large fires. Their primary purpose is for broad-scale analysis, and not detailed site-specific views of vegetation.

The data from the maps were separated by the ecological subregions and in some cases ecological zones that were described previously. Additional information on vegetation condition is currently being summarized from detailed ground plots, the national forest inventory and analysis plots, but is not available at this time. Using the plot data, additional indicators will be summarized that were identified such as within stand variability in vegetation structure and successional patterns.

There are both common patterns and obvious contrasts in the vegetation patterns amongst the different subregions across the assessment area. The vegetation type maps highlight some of the major changes that occur from west to east and north to south.

Southern Sierra Subregions, West and East
In the southern Sierra Nevada, the higher elevation of the mountain crest results in noticeable changes with elevation from a large area of oak woodlands and chaparral on the western slopes, up into mixed conifer, where the remarkable giant sequoia grows, to red fir and then a relatively large band of high elevation subalpine and alpine vegetation. Moving down the east slopes, there are more rapid transitions from one vegetation type to another and a large area of Great Basin and Mojave desert influenced pinyon-juniper, sage scrub and desert vegetation. Notable at the higher elevations in the mountains on the eastern edge of the Inyo National forest, are the Bristle cone pine forests. The southernmost portion of the bio-region, is transitional to the more open, xeric and desert like vegetation of Southern California mountain ranges.

Southern Sierra Nevada
The largest expanse of western slope hardwoods occurs within national forest boundaries in the Southern Sierra Nevada within the Sierra and Sequoia National Forests. This is significant because the oak woodlands are amongst the most fragmented and developed vegetation types in California. Canopy cover is greater on the west slopes of the Sierra Nevada than in the higher elevations, although in general extensive areas of dense forest are less prevalent in the south than in the north, where higher average precipitation is common.
On the west slopes, most of the forests are mid-sized, with average diameters of 12 to 24” dbh. Areas with larger average diameters, >24” are distributed throughout. The giant sequoia groves contribute to these patch types, with almost half of the mixed conifer classified as late seral (USDA 2012: p. 65). In the groves, diameters of trees exceed those in any other forest in the Sierra Nevada.

ADDTEXT HERE

Existing vegetation patterns in the Southern Sierra Nevada, west of the mountain crest. Based upon remote-sensing (LANDSAT) derived maps produced by the US Forest Service Remote Sensing Lab. CWHR is the California Wildlife Habitat Relationships classification commonly used in the state on all lands.

View WHR Type, Description, Group, Species, and Lifeform Classes PDF in a new window


South - Southern Sierra Nevada
EcoType_South.jpg
aChap1_Bio_Lifeform_South.jpg
cwhrdensitysosn.jpg
cwhrsizesosn.jpg
aChap1_Bio_SizeDensity_South.jpg


Eastside – Southern Sierra Nevada
EcoType_East-South.jpg
aChap1_Bio_Lifeform_EastSouth.jpg
cwhrdensityeastsouthsn.jpg
cwhrsizeeastsouth.jpg
aChap1_Bio_SizeDensity_EastSouth.jpg

Central Sierra Nevada
EcoType_Central.jpg
aChap1_Bio_Lifeform_Central.jpg
cwhrdensitycentral.jpg
cwhrsizecentral.jpg
aChap1_Bio_SizeDensity_Central.jpg

Northern Sierra Nevada and Southern Cascades – Westside
EcoType_North.jpg
aChap1_Bio_Lifeform_North.jpg
CWHR_Density_North.jpg
CWHR_Size_North.jpg
aChap1_Bio_SizeDensity_North.jpg

Northeast Sierra Nevada, Southern Cascades and the Modoc Plateau
Ch1_Terrestrial_CWHR_Type_EN_sm.jpg
Ch1_Terrestrial_CWHR_Lifeform_EN_sm.jpg
Ch1_Terrestrial_CWHR_Density_EN_sm.jpg
Ch1_Terrestrial_CWHR_Size_EN_sm.jpg
Ch1_Terrestrial_CWHR_SizeDen_EN_sm.jpg

Ecological Integrity – Biological Diversity


This section focuses on the fine-filter level of biodiversity, individual species or groups of species in limited habitats. Information is limited and draws from the topical papers on Species of Conservation Concern (Chapter 5, WIKI) and Ecological Integrity (Chapter 1-Terrestrial Ecosystems, WIKI). Focal species, individual habitat elements (i.e. snags, large trees, within forest heterogeneity and understory plant patches), and limited habitats (i.e. aspen, recently burned forests) are discussed.

Over 1000 species were considered (1077) (Chapter 5 WIKI) but is an overestimate of what occurs on the national forests since data came from county or map quadrangle levels. Careful review and evaluation at the forest scales, to determine what occurs within national forest boundaries is currently underway. At this time, preliminary information (overestimate) includes over 100 threatened and endangered species, including: 30 fish, 19 amphibians, 98 invertebrates, 41 birds, 6 reptiles, 33 mammals, and 505 plants. The final list of species of concern will be decided upon by the regional forester, once the revised potential list is completed.

The concepts of management indicator species, keystone species or other terms used to identify a few number of species to represent impacts of management or environmental stressors (e.g. climate change) with changes to the habitats they represent is controversial. In the new planning rule, the concept of focal species is proposed with the intent to pick a reasonable number of species to evaluate and monitor over time. Noon et al. (2009) and Schultz et al. (2013) suggest criteria and processes for selecting focal species: base on a conceptual model of ecological processes and functions; include species that are indicators to key stressors, play a role as engineers of ecological processes, play an important role in food web dynamics, and are threatened/at risk/rare species; using a formal process. We provide some examples that meet the criteria proposed, some also addressing coarse-filter connectivity issues. Here, emphasis is on land-based species (terrestrial), water-based (aquatic) species are covered in the previous water section.

Spotted owls, fisher, pine marten, sage grouse, aspen, and large trees meet several of these criteria and also help assess landscape connectivity for key habitats: old forest and eastside sagebrush. All are at risk, rare or threatened, sensitive to stressors (i.e. high severity, large fires), and important in food web dynamics. Additional species, or fine-filter elements meeting multiple criteria include: large, especially old trees (habitat engineers, limited or rare, at risk); woodrats (important prey, nests are home to hundreds of insects and many reptiles); and woodpeckers (engineers of cavities used by many species -flying squirrels and cavity nesting birds); large snags (critical habitat for many species, often limited or very patchy due to past management); and amphibians (sensitive to climate change, air quality stressors, changes to riparian and aquatic ecosystems). Other engineers playing critical roles in ecosystem processes include carpenter ants (initial decomposition of large woody debris, and food source for many), fungi (mychorrizal relationships with trees and other plants), and bees (pollination and sensitive to stressors). In addition to focal species, for some taxa, community composition, or all of the co-occurring species in an area, are also useful. For example birds in various habitats (Chapter 1 WIKI) from Partners in Flight (http://www.prbo.org/calpif/). For plants, selections might include: cheatgrass (invasive grass that is a major stressor, changing fire regimes, soil fungi composition and levels, and constricting habitat of native and some key endangered species—i.e. sage grouse); aspen (at risk from fire suppression and other stressors, associated with rich and diverse floristic assemblages, critical habitat for numerous bird species); or forest understory plants requiring sunlight in small patches, particularly those with life histories enhanced by fire (fire stimulated flowering such as bearded penstemon or many lilies- Fites-Kaufman et al. 2006) that are stressed by fire deficits. A synopsis of current condition, trends and implications for restoration for large trees, snags, special habitats, and overall within-forest habitats are below. Some aspects were referred to previously in the NRV discussion.

Snags and large trees are highly variable in the landscape. Overall, large tree density and extent vastly is lower compared to historic conditions, particularly for foothill and montane pine and mixed conifer forests. Recent, large high severity fires have further reduced large trees, often old trees (>200 years old) that will take a very long time to replace. Recent concentrations of these fires on the Plumas and Lassen National Forests (Chips, Antelope, Moonlight fires) have resulted in large areas that had few large trees to begin with and now have only scattered remaining large trees. Large tree mortality and vigor have been reported, particularly in the southern Sierra Nevada, attributed to combined causes of increased forest density (vulnerability to moisture stress), ozone, and climate change (Van Mantgem and Stephenson 2007).

Snag densities and sizes are highly variable. In unburned forests, large snags tend to be low density, and smaller snags can be higher density, but in burned forests, there may be extensive areas of snags of all sizes in concentrations atypical of NRV (areas of large extent) (Safford 2013). The latter pattern is most prevalent in montane pine and mixed conifer forests but more uncommon and uncertain as to the status relative to NRV in upper montane forests (Meyer 2013).

Information on the occurrence and extent of specific habitats (contrasting with coarse-filter) is limited and the ecological condition is more uncertain than for common forest types. They are important to consider because they often serve as “hotspots” for uncommon, rare, or diverse assemblages of species. Similarly, understory herbs and grasses, often occur in patches at a fine-scale that is not mapped, such as forested openings, limestone rock outcrops, or fens. These elements of biodiversity will be covered in more detail at the individual forest scale, where it is possible to distinguish and describe them adequately. Here we display examples of the rich array that occur across the bioregion and distributions that cross land ownerships and administrative forest boundaries. Aspen and meadows are particularly vulnerable to climate change and in the dry Mediterranean and Great Basin climates of the bioregion, are important for many species of plants and animals. These were discussed in the NRV section as was montane chaparral, sagebrush, and oak/hardwood communities. Aspen depicted in this map is an overrepresentation because in its current, highly fragmented condition, it does not show up unless the locations are magnified (as we have done). Other special habitats, including Bristecone pine and giant sequoia illustrate the very limited distribution of these unique and well-loved plant communities. Recently burned patches can attract and support many species, in particular birds such as Olive-sided Flycatcher, Fox Sparrow, Yellow and MacGillivray’s Warblers, and Dusky Flycatcher , and black-backed woodpeckers (http://www.prbo.org/cms/docs/edu/NSierraShrub.pdf). They can provide both shrub rich environments as well as complex, early seral habitats (combination of post-fire shrubs, herbs, and legacy snags and logs). The pattern of recently burned areas is vastly different in montane forests than evidence from NRV indicates (Safford 2013). The patches are larger across continuous areas but vastly decreased as smaller patches, particularly within-stand scale (North 2012).

This uniformity, along with absence of low to moderate intensity fire, has resulted in a vast reduction in fine-scale forest heterogeneity or complexity. Small, sunny openings, favored by some plants are relatively rare. Areas cleared of dense, deep leaf and needle litter are uncommon, impeding germination of some types of plants. Shrubs and herbs that need sun and often fire to flower or develop vigorous foliage are scraggly or decadent. As a result, understory animals, such as rodents (mice, squirrels, woodrats) and songbirds, that depend on the plants in these small openings or sunnier, burned spots are decreased. The trend for homogenization and lack of fire to invigorate understory plants will continue. On the other hand, as discussed in the fire and NRV section, the trend is for larger patches of uniform, early aged, or early seral vegetation to develop after fire. This can be good for plants and animals associated with these habitats. But the patches are often very large, compared to historic patterns, and widely distributed in the bioregion, limiting movement of species between them, or connectivity.

Ch1_Terrestrial_Early_Seral_Veg.jpg
Ch1_Terrestrial_PctEarlySeral.jpg

Fine-Scale Vegetation Structure

Several measures were selected that are important to ecological integrity, have been affected by stressors or land-use, and for most have readily available information (as directed in the planning rule). These include within-forest heterogeneity (North xxxx), floristic fine-scale habitat (within patch), snags and large trees. These fall into an “intermediate” filter level of ecological integrity. Some additional limited habitat types of concern were also included. They are more general than individual species, but more refined than coarse-filter, broad habitat types or connectivity patterns. Detailed information on these characteristics are found in the topical paper on Ecological Integrity (Chapter 1, WIKI), and the Science Synthesis (Chapter 2; Forests: North 2013), North et al. (2009), and North (2012).


Vegetation Fine-Filter (Structure and Composition within Patches and Stands)


I. Within Stand Variation of Forest Structure of structural heterogeneity

Link to new page with graphs for Within Stand Variation of Basal Area for all Forests

II. Large Trees By Administrative Unit and Forest Type

Comparing Southern Sierra Forests


Inyo National Forest

Sequoia National Forest

Sierra National Forest

# of Plots
≥21
≥24
≥30
≥40
≥50
# of Plots
≥21
≥24
≥30
≥40
≥50
# of Plots
≥21
≥24
≥30
≥40
≥50
Conifer
240





247





312





Median

11.1
6.9
3.0
0.6
0.0

17.2
13.0
6.5
1.3
0.1

11.9
8.3
3.8
1.0
0.2
Mean

12.5
8.2
3.9
1.1
0.1

18.3
13.7
7.1
1.7
0.2

14.9
10.3
5.2
1.6
0.5
CV

55%
56%
72%
105%
162%

59%
56%
69%
106%
59%

96%
102%
122%
193%
221%
Conifer Hardwood
2





25





39





Median

6.0
6.0
2.0
0.7
0.0

16.0
6.0
1.0
0.0
0.0

8.0
4.0
1.0
0.0
0.0
Mean

6.0
6.0
2.0
0.7
0.0

18.0
9.5
4.1
1.0
0.0

8.2
5.6
2.9
0.9
0.2
CV

47%
47%
47%
141%
0%

90%
102%
129%
203%
500%

87%
106%
136%
217%
624%
Oak Woodland
3





56





70





Median

16.0
8.0
0.0
0.0
0.0

1.0
0.4
0.0
0.0
0.0

2.7
0.7
0.0
0.0
0.0
Mean

16.0
8.0
0.0
0.0
0.0

2.6
1.3
0.2
0.0
0.0

5.8
2.8
1.2
0.4
0.1
CV

100%
100%
0%
0%
0%

124%
113%
131%
88%
0%

168%
160%
201%
120%
211%
Riparian Wetland
13





5





9





Median

0.8
0.8
0.3
0.0
0.0

0.0
0.0
0.0
0.0
0.0

0.0
0.0
0.0
0.0
0.0
Mean

0.9
0.9
0.4
0.0
0.0

0.0
0.0
0.0
0.0
0.0

1.2
0.6
0.1
0.0
0.0
CV

153%
153%
153%
0%
0%

0%
0%
0%
0%
0%

182%
240%
300%
0%
0%

Link to new page with Large Trees for all Forests


III. Shade Tolerance by Ownership and Forest Type

Comparing Southern Sierra Forests

Inyo National Forest
Sequoia National Forest
Sierra National Forest

# of Plots
< 12
≥ 12
# of Plots
< 12
≥ 12
# of Plots
< 12
≥ 12
Conifer
240


247


312


Mean

7%
7%

26%
17%

26%
16%
CV

196%
198%

86%
107%

182%
240%
Conifer Hardwood
2


25


39


Mean

5%
0%

56%
35%

58%
28%
CV

141%
0%

75%
100%

64%
122%
Oak Woodland
3


56


70


Mean

9%
0%

32%
10%

51%
20%
CV

173%
0%

91%
107%

79%
156%
Riparian Wetland
13


5


9


Mean

0%
0%

46%
0%

67%
6%
CV

105%
0%

7%
0%

64%
300%

Link to new page of Shade Tolerance for all Forests

IV. Snags by Ownership and Forest Type

Comparing Southern Sierra Forests

Inyo National Forest
Sequoia National Forest
Sierra National Forest

# of Plots
≥ 15
# of Plots
≥ 15
# of Plots
≥ 15
Conifer
240

247

312

Mean

2.7

3.0

3.7
Median

1.1

1.3

1.3
St. Dev

5.5

5.6

6.1
CV

112%

101%

206%
Conifer Hardwood
2

25

39

Mean

0.7

2.7

2.6
Median

0.7

0.0

0.0
St. Dev

0.9

5.2

6.1
CV

141%

191%

233%
Oak Woodland
3

56

70

Mean

1.3

1.3

1.0
Median

0.0

0.0

0.0
St. Dev

2.3

4.3

3.2
CV

173%

64%

353%
Riparian Wetland
13

5

9

Mean

1.0

0.3

0
Median

0.2

0.3

0
St. Dev

4.2

0.4

0
CV

153%

71%

0

Link to new page for Snags for all Forests

INSERT Forest Inventory and Analysis (FIA) data on: forest heterogeneity; forest density; large trees; snags, logs; and dominant tree composition

V. Understory Floristic Diversity

The emphasis of this section is to address background on floristic diversity, including the ecology of plants, moss and other bryophytes, and lichens. Floristic diversity is very rich in California, including in the Sierra Nevada. In Chapter 5, Species at Risk, specific species are addressed that include threatened and endangered, management indicator species - Planning Rule dismisses use of MIS - will these still be included in Ch. 5?, or species of concern. As readily apparent in that chapter as well as the background below, there are hundreds of species of plants that are considered at risk. Given this enormous number, it is important to also assess a more “coarse-filter” view of floristic diversity; where we have measurable information. For a coarse-filter approach, we are using a “habitat guild” or “life history group” approach- most useful for addressing the large number of rare species that need to be discussed in Ch. 5 The indicator for rare communities/special habitat types, along with FIA and/or TEUI plot data, may be more useful for this Ch. 1 discussion of diversity?. This was utilized in the 2001 Sierra Nevada Forest Plan Amendment EIS (USFS 2001: Vol. 3, Chapter 3, Part 4, Section 4.6). The other primary source of information used in the background is from the scientific assessment by Dr. Shevock in the Sierra Nevada Ecosystem Study Project (1996).

Background Excerpt from Status of Rare and Endemic Plants from the SNEP Report
This excerpt paints a picture of California’s plant diversity; provides background for impact of invasives on California’s botanical treasures; shares unique, special places in California and glimpse of the value of plants for enjoyment of California’s people and future generations.

The Sierra Nevada represents nearly 20% of the California land base yet contains over 50% of the state’s flora. Approximately 405 vascular plant taxa are endemic to the Sierra Nevada. Of this total, 218 taxa are considered rare by conservation organizations and/or state and federal agencies. In addition, 168 other rare taxa have at least one occurrence in the Sierra Nevada. Five monotypic genera are endemic to the Sierra Nevada (Bolandra, Carpenteria, Orochaenactis, Phalacoseris, and Sequoiadendron). Information on rarity and endemism for lichens and bryophytes for the Sierra Nevada is very speculative and fragmentary due to limited fieldwork and the small number of available collections. Two mosses are endemic to the Sierra Nevada. Parameters obtained for each rare and/or endemic taxon include habitat type and distributions by county, river basin, and topographic quadrangle. Distribution information for many taxa remains incomplete based on limited field studies and vouchered specimens, especially in the more unroaded and rugged areas of the Sierra Nevada. Rare and endemic species are not evenly distributed throughout the Sierra Nevada. The Kern, Kings, Merced, San Joaquin, Tuolumne, and Feather River Basins contain the largest concentrations of rare and endemic taxa in the Sierra Nevada. For the eastern slope of the Sierra Nevada, the Owens River Basin is rich in species composition as well as rare and endemic taxa. Of the three geographical subunits, the northern, central, and southern Sierra, the southern Sierra is extremely rich in endemics, rare species, and total floristic composition. Adverse impacts to some Sierran rare plants are occurring along the western fringe of the range adjacent to the Central Valley, where conversion of lands to agriculture and urbanization may greatly restrict or alter essential habitat for some Sierran endemics and/or rare species.

For more than 100 years, the flora of the Sierra Nevada has fascinated botanists even beyond the borders of the United States. Visions of Yosemite, giant sequoias, and extensive mixed conifer forests have added to an awareness of this magnificent mountain range. The Sierra Nevada, part of the California Floristic Province, is characterized by high rates of plant endemism (Stebbins and Major 1965; Raven and Axelrod 1978; Messick 1995). For most of this century, plant collecting and floristic research remained the pursuits of professional botanists with ties to major scientific and educational centers (Shevock and Taylor 1987). Floristic studies have as one of their primary goals documentation of all the taxa (species, subspecies, varieties) for a particular geographic region and determination of their distribution and abundance within that study area (Palmer et al. 1995). Rare, endemic, and disjunct taxa have a special place in such studies because they contribute to the diversity and uniqueness of a flora. Remarkably, the Sierra Nevada lacks a comprehensive floristic treatment. Portions of the range are covered by a great variety of floristic studies, ranging from detailed floras to florulas and checklists. Floristic studies generally fall into four categories: county floras (Clifton 1994; Oswald 1994; True 1973; Twisselmann 1967), floristic tudies by watershed (Henry 1994; Lavin 1983; Palmer et al. 1983; Savage 1973; Shevock 1978; Smith 1973, 1983; Taylor 1981), studies based on park or preserve boundaries (Gillett et al. 1961; Knight et al. 1970; Potter 1983; Pusateri 1963; Rice 1969; Showers 1982), and studies by specific topographical features and habitats (Forbes et al. 1988; Howell 1951; Hunter and Johnson 1983; Sharsmith 1940; Smiley 1921; Tatum 1979; Williams et al. 1992 Much acreage remains in the Sierra Nevada that is not botanically surveyed or systematically vouchered, especially in unroaded or relatively rugged areas.

With the passage of the federal Endangered Species Act of 1973 (ESA, as mended) came a distinct shift in plant collecting and subsequent conservation efforts toward a focus on those taxa believed to be candidates for threatened or endangered status. These distribution data were increasingly obtained by plant enthusiasts, botanical consultants, and various state and federal agency botanists rather than traditional academic botanists with ties to major educational institutions (Ertter 1995; Shevock and Taylor 1987). Initially, the information available to determine which taxa were in fact rare and/ or endemic was fragmentary, with most information restricted to a handful of herbarium specimens (Powell 1974). With efforts directed at rediscovery of old herbarium records, along with systematic and focused fieldwork to document new occurrences, understanding of the distribution of rare and endemic species has greatly improved (Smith et al. 1980; Smith and York 1984; Smith and Berg 1988; Skinner and Pavlik 1994). Floristic inventories are becoming ever more important as a method of documenting the plant diversity of a specific landbase. However, many of the currently available floras and checklists lack citations of representative vouchered specimens to validate each of their entries. Without references to vouchered plant material deposited in major erbaria, these floras and checklists have reduced value because material on which the catalogue of names is based is not available for future study and taxonomic review (Palmer et al. 1995; Ferren et al. 1995). Of course, many floras are based on a review of herbarium records, but again, representative specimens are rarely cited in the publication of floristic studies. Wilken (1995) provides a convincing case for continued floristic studies in California that emphasize comparative analyses based on biogeographical patterns of diversity at both regional and local levels. It may come as a surprise to many not familiar with the California flora that vascular plants are still being discovered and described as new to science for the Golden State. The majority of these newly published species are both endemic and rare.

The period 1968–86 yielded over 220 newly described vascular plant taxa for California; sixty-five of these occur in the Sierra Nevada (Shevock and Taylor 1987). With publication of The Jepson Manual (Hickman 1993), ongoing floristic analysis by Shevock and Taylor (in preparation) will document that since 1986 this trend of discovery and publication of new vascular plant taxa continues. The southern Sierra Nevada in particular, along with other areas of carbonate and serpentinite geology, remains an area of the state worthy of continued floristic study and research (Norris 1987; Shevock 1988). During the past few years several new species have been discovered in the Sierra Nevada. Because many of these new taxa are rare and/or endemic to a single river basin, they are incorporated in this assessment with the specific epithet “sp. nov.,” “ssp. nov.,” or “var. nov.” until the names have been effectively published according to the International Code of Botanical Nomenclature. This assessment was developed to determine the distribution of both endemic and rare plant taxa in the Sierra Nevada, primarily at the river basin level. For the core study area, the Sierra Nevada was divided into twenty-four river basins (figure 24.1) ranging in size from the Feather at 971,611 ha (2,399,878 acres) to the Calaveras at 94,018 ha (231,285 acres). River basin boundaries are useful because they are easy to determine both in the field and on maps, in contrast to political boundaries such as counties, forests, and parks, which have the potential to change through time. Furthermore, river basins provide a biogeographical context in which to evaluate floristic components such as rare and/or endemic species. Size, elevation range, geology and soils, vegetation types, and geographical location of each river basin are factors used to speculate why river basins vary widely in total number of taxa, including rare and endemic species. As a general overview, the northern Sierra is predominantly volcanic in origin, and the central and southern Sierra are both mainly granitic, with several areas of metamorphic and metasedimentary parent materials.

The diversity of habitat types that occur in the Sierra Nevada also explains the great richness of endemic and rare species within this mountain range. The broad plant communities used by Munz and Keck 1959, along with those used in Skinner and Pavlik 1994, provide the basis for recording habitat preferences for rare and/or endemic taxa in this study. Several additional habitat types not based on vegetation were recorded, because many rare taxa seem to be more dependent on them than on the surrounding vegetation type. For example, seventy taxa, or nearly 12% of rare and/or endemic taxa, can be found on rock outcrops. Many endemics and/or rare taxa are located exclusively on a particular rock type, such as carbonate, serpentine, basalt, or granite. Other taxa have distributions that correspond more closely with elevation zones or that span several habitat types. Distribution patterns for rare and/or endemic species differ considerably from river basin to river basin, and the distribution of these elements between habitat types is also varied. There are five dominant habitat types: Jeffrey and ponderosa pine forest types contain 211 taxa, the largest concentration of rare and endemic elements in the Sierra; the second largest, the foothill woodland, contain 139 taxa; subalpine forests contain 124 taxa; meadows have 116 taxa; chaparral, 90 taxa. Of the five habitat types that contain the most rare and endemic taxa, the foothill woodland and chaparral are receiving the greatest increase in impacts and/or fragmentation by urbanization along the western slope of the Sierra Nevada. In chaparral vegetation types, the frequency of fire has been altered to protect other resource values, such as timber and homes. An example of this change in the Sierra Nevada is occurring at the residential development areas of Cameron Park, Pine Hill, and Salmon Falls in El Dorado County. Several rare taxa are restricted or locally endemic to gabbro soils in this area and are impacted by a direct loss of habitat by development. Those taxa that are dependent on fire as part of their life history and ecology may be negatively impacted by long-term changes in the management of chaparral vegetation. The changes may include a shift from fall to spring burning, mechanical treatments, or alteration of the fire frequency.

Habitat or Functional Floristic Guilds

The term “guild” in used in ecology to mean a group of species that use similar resources in a similar way (Root 1967), occur in similar habitat, and respond to processes such as fire or floods in the similarly. Species may be grouped by their edaphic (soil), moisture, or canopy closure requirements, associated vegetation types, or how they obtain “food” (e.g. photosynthesis or saprophytic). For example, a group of plants adapted to riparian forests could be said to comprise a riparian guild. Or a group may be based on plants that occur in sunny openings in forests, or unburned, litter rich, shady forest patches. The groups or guilds for this assessment are in progress but will be generalized as to what can be assessed with existing information at the bio-regional scale. This is likely to include: vegetation type, canopy cover, time since fire (at different severities), and within-stand vegetation heterogeneity. If possible, edaphically defined guilds may also be addressed, but it depends on the resolution and quality of available data. Guilds can vary in space (where they occur) or time (temporal), such as after a fire or flood.

The guilds used in the 2001 Sierra Nevada EIS included the following groups table below. We will be reducing the list by combining groups and perhaps adding others. For many of these we do not have spatial data.

Spatially Defined Guilds.
Meadows and Seeps
Vernally Wet
Riparian Woodland
Riparian Forest
Bogs and Fens
Non-forested Lakes and Streamsides
Rock Outcrops
Ultramafic (serpentine)
Cliff
Edaphic specialists
Temporally Defined Guilds
Interior (Old Growth) Forest
Openings (Small Gaps) in Forests
Post-fire Openings
General Openings

Edaphic habitats

Edaphic habitats are those where the ecology of a site is driven principally by soil conditions. These include areas underlain by ultramafic rock (“serpentine”), calcareous rock (limestone and marble), and areas of thin or nonexistent soil, such as rock outcrops and cliffs. Soils developed on ultramafic rocks are characterized by very low levels of most important plant macronutrients, including calcium, potassium, and nitrogen, and high levels of potentially toxic heavy metals such as chromium, nickel and cobalt. These habitats often develop open forest or shrublands characterized by stunted, slow-growing vegetation. The challenging conditions on serpentine soils result in the occurrence of many rare and endemic plant species. Soils developed on calcareous rocks are enriched in calcium, and can provide excellent growing soils under high precipitation regimes but are often rocky and thin in semiarid landscapes like much of the assessment area. Calcareous soils also support some rare and endemic plant species, mostly in the southern assessment area. Rock outcrops and cliffs may occur on any bedrock type. They present challenging conditions for growth simply due to the general absence of soil. These habitats are common throughout the assessment area.

All of these edaphic habitats are generally unproductive and tend to support vegetation dominated by scattered herbaceous plants and shrubs, or open forests where conditions allow. The lack of dense vegetation and slow succession on these habitats also results in less frequent fire and there is evidence that the occurrence of some rare and endemic species is more closely tied to escape from frequent fire than escape from biological competition.

In the northern assessment area, many areas of ultramafic soil are found in and around populated areas at lower elevations and urban and suburban expansion is impacting increasing areas of habitat. Because of slow growth, cutting of trees on ultramafic soils has much longer-lasting ecosystem effects than on more productive soils.

Examples of edaphic habitats from the eastside on the Inyo National Forest include the following types: • Carbonate (C) – includes those species restricted to carbonate substrates; Alkali Flat (AF) – includes species found in highly alkaline soils.

Meadows and seeps

Meadows occur where herbaceous plant species dominate the site. Meadows can be divided into two broad hydrologic types: groundwater fed meadows and dry meadows. Groundwater-fed meadows occur where there is a shallow water table, and finely textured soils accumulate (Ratliffe 1985). Dry meadows occur where the water table is deep but there is sufficient soil moisture at some point in the year, usually spring or early summer, to allow herbaceous species to establish and become dominant. Woody species may occur on these meadow types but they are not the dominant vegetative cover. Both groundwater-fed and dry Meadows occur in a number of different settings and are fed by a variety of water sources (Weixelman et al. 2011). Meadows occur in depressions where water collects (depressional meadows), adjacent to flowing streams (riparian meadows), adjacent to lakes or reservoirs (lacustrine fringe), near springs and seeps (discharge slope), or meadows may occur in valley bottoms with no flowing stream and only subsurface water feeding the meadow (subsurface meadows).

Plant species that dominate groundwater-fed meadows are typically hydric species adapted to a shallow water table (Fites-Kaufmann et al. 2005). These include sedges (Carex spp.), rushes (Juncus spp.), and grasses and forbs adapted to shallow water tables. Dry meadows contain herbaceous species adapted to drier soils and are typically less productive. Plant species that occur in meadows and seeps can be classified into groups that respond similarly to management (Weixelman and Gross, unpublished). These are termed plant functional groups. For example, plants that tolerate disturbance, e.g. trampling or grazing, are termed ruderal species (Winward 2000). These are species that are adapted to disturbance and tend to increase with disturbance in a meadow. Examples include dandelion (Taraxacum officinale), western aster (Aster occidentalis), and western yarrow (Achillea millefolium). Some species do not tend to increase with disturbance but instead decrease with disturbance. These are called late successional plant species or competitors. Examples include Nebraska sedge (Carex nebrascensis), and beaked sedge (Carex utriculata). Of importance to managers is knowing the proportions of these plant groupings, or plant guilds, in a meadow. For example, these plant groupings can be used to assess the ecological integrity, or ecological health, of the meadow in terms of species composition and the level of disturbance that is occurring. These species groupings, as used in this example, can be used in both groundwater-fed meadows and dry meadows to assess the condition of the meadow. Other metrics such as species richness and diversity are generally controlled by both the type of meadow and the level of disturbance on a site (Safford et al. 2001).

Other indicators of ecological integrity in a meadow include the amount of stream incision that may have occurred (Simon and Rinaldi 2006). Stream incision, or downcutting of the stream channel affects the timing and duration of flooding the meadow receives, as well as the level of the groundwater in many meadow systems, which in turn affects the ability of the meadow to support hydric vegetation and desired habitat for a multitude of meadow fauna (Loheide et al. 2009). An additional indicator of meadow ecological integrity is the amount of encroachment by upland plant species including coniferous species. Encroachment by these types of species can indicate drying of the meadow due either to management actions and/or climatic influences. Ecological assessment of meadows often takes into account factors related to both hydrology and vegetation of a meadow area (Stillwater Sciences 2012, Gross et al., unpublished).

References
  • Fites-Kaufman, J, P. Rundel, N. Stephenson, D. A. Weixelman. 2007. Montane and Subalpine Vegetation of the Sierra Nevada and Cascade Ranges. Pp 456-501. In: M.G. Barbour,T. Keeler-Wolk, and A.A. Schoenherr, eds. Terrestrial Vegetation of California, 3rd ed. Ed: University of California Press, Berkeley, CA, 712pp.
  • Gross, S.E., Weixelman, D.A., and H. Safford. Using an ecological framework to track meadow health and function in the Lake Tahoe Basin. Unpublished manuscript, to be submitted, Spring, 2013.
  • Loheide, S.P., Deitchman, R.S., Cooper, D.J., Wolf, E.C., Hammersmark, C.T., and Lundquist, J.D. (2009) A framework for understanding the hydroecology of impacted wet meadows in the Sierra Nevada and Cascade Ranges, California, USA.
  • Ratliff, R. D. 1985. Meadows in the Sierra Nevada of California: state of knowledge. Gen. Tech. Rep. PSW-84. Pacific Southwest Forest and Range Experiment Station, USDA Forest Service, Albany, California.
  • Safford, H.D., M. Rejma´nek, and E. Hadac. 2001. Species pools and the ‘‘hump-back’’ model of plant species diversity: an empirical analysis at a relevant spatial scale. OIKOS 95: pp. 282–290.
  • Simon, A., Rinaldi M., 2006. Disturbance, stream incision, and channel evolution: The roles of excess transport capacity and boundary materials in controlling channel response. Geomorphology 79 (2006) 361-383.
  • Stillwater Sciences. 2012. A guide for restoring functionality to mountain meadows of the Sierra Nevada. Prepared by Stillwater Sciences, Berkeley, California for American Rivers, Nevada City, California.
  • Weixelman, D. A., B. Hill, D.J. Cooper, E.L. Berlow, J. H. Viers, S.E. Purdy, A.G. Merrill, and S.E. Gross. 2011. A Field Key to Meadow Hydrogeomorphic Types for the Sierra Nevada and Southern Cascade Ranges in California. Gen. Tech. Rep. R5-TP-034. Vallejo, CA. U.S. Department of Agriculture, Forest Service, Pacific Southwest Region, 34 pp.
  • Weixelman, D.A, and Gross, S.E. 2013. Plant functional groups in relation to disturbance and hydrology in mountain meadows, Sierra Nevada and Southern Cascade Ranges, CA. Unpublished manuscript, to be submitted Spring, 2013.
  • Winward, A.H. 2000. Monitoring the Vegetation Resources in Riparian Areas. USDA Forest Service, Rocky Mountain Research Station. RMRS-GTR-47.
  • Yarnell, S.M., J.H Viers, and J.F.Mount. 2010. Ecology and management of the spring snowmelt recession. Bioscience: Vol. 60 No. 2. Pp 114-127.


Riparian Forest and Woodland Guild


Importance of Guild

Riparian forests represent a keystone community type, playing a more significant ecological role than their proportional area in the landscape would suggest (Gregory et al. 1991; Malanson 1993). Currently, the amount of land in the assessment area classified as riparian forest habitat type is only 58 km2, with an additional 119 km2 of riparian scrub (Kattelmann & Embury 1996). Yet riparian ecosystems in the Sierra Nevada, as elsewhere, provide many important ecological services, including: streambank stabilization, sediment retention, water quality improvement, hydraulic process moderation, and wildlife species habitat provisioning (Patten 1998). Key hydrologic functions provided by riparian vegetation include: improving water quality by trapping and filtering sediment, nutrients, and pollutants; reducing flood damage and enhancing ground-water recharge by slowing water velocity and increasing river surface area; and maintaining an elevated water table by preventing channelization (Patten 1998). Today, Sierra Nevada runoff provides almost 65% of water for agricultural and other human uses in California (Timmer 2003). Riparian communities contain more plant and animal species than any other California community type (Schoenherr 1992) and about one fifth of terrestrial vertebrate species in the Sierra Nevada depend on riparian habitat (Kattelmann & Embury 1996). Riparian zones also play an important role as ecological corridors (Naiman & Decamps 1997) and recreational sites.

Guild Description

Species of the riparian forest and woodland guild generally share the following ecological traits: broad-leaved; winter-deciduous; fast-growing; short-lived; requiring high soil-moisture; tolerant of flooding and low oxygen root environments; and able to produce sprouts, suckers, and new root systems (Kattelman & Embury 1996). Riparian tree species can generally be divided into two main categories: pioneer species and secondary successional species (Vaghti & Greco 2007). Pioneers, which include species of Salix, Platanus, Populus, and Alnus, often release their water/wind born seeds in late spring, when flooding creates moist, available substrate (Vaghti & Greco 2007). They rely on flooding to create habitat and low summer flows to promote seedling survival (Vaghti & Greco 2007). They are fast growing and produce debris like leaf litter that aids in soil development. Later seral species, like those of Acer, Fraxinus, and Quercus then grow up through the accumulated litter in areas where less frequent flooding occurs (Vaghti & Greco 2007).

In general, as slope increases, as substrate coarsens, and/or as flooding frequency increases, riparian communities tend to simplify (Harris 1989; Harris 1999). Depth to water table is a key determinant of vegetation patterns within riparian areas (Loheide & Gorelick 2007; Elmore et al. 2003), with obligate wetland plants (e.g. Salix gooddingii) giving way to facultative wetland plants (e.g. Populus fremontii) and facultative riparian conifers (e.g. some Pinus spp. and Caocedrus decurrens), and finally to upland species (e.g. Abies concolor ) and some oak (Quercus spp) in the outer floodplain locations as depth to groundwater increases (Stromberg et al. 1996; Harris 1989). Particular dominant vegetation is often associated with specific substrates or locations within the channel profile (e.g. Willows (Salix spp.) are often associated with sand and cobble substrates and alders (Alnus spp.) are often found immediately adjacent to channels; Harris 1989).

Disturbance is particularly important to riparian ecosystems as many riparian plants are disturbance adapted (Kobziar & McBride 2006; Naiman & Decamps 1997; Naiman et al. 1998; Potter 2005; Vaghti & Greco 2007). Plant distribution and composition depends on both fluvial disturbance (e.g. debris flow, floods, scouring) and nonfluvial disturbance from adjacent upland ecosystems (e.g. fire, wind, disease, avalanche, herbivory, pests, etc.; Gregory et al. 1991; Naiman et al. 1998). Riparian conditions (e.g. flooding, depth to water-table) are often the dominant force driving riparian stand composition in the Sierra Nevada, with fire playing a significant, though less prominent role (Russell & McBride 2001; Stromberg & Patten 1996). Under natural flow regimes in the Sierra Nevada, variation in flood frequencies, levels, and durations creates a diversity of age and structural conditions within riparian communities. These processes often result in high levels of patchiness through both space and time, with average riparian plant associations existing in patches smaller than 0.1 hectares or 0.25 acres (Kattelmann & Embury 1996; Kobziar & McBride 2006; Potter 2005).

Current Condition & Management Considerations

Despite evidence than many riparian zones (particularly bordering steeper, narrower, or more incised streams) historically exhibited fire return intervals (FRI) similar to those of surrounding upland areas, management plans in the assessment area often exclude any sort of disturbance-based management in riparian zones (Van de Water & North 2010). Mechanical thinning, as well as prescribed burning and managed wildfire, are frequently prohibited in the riparian corridor due to concern for both water quality and sensitive riparian ecosystems (Kobziar & McBride 2006). This policy may have both positive and negative impacts on the riparian guilds, including reduced fire-related erosion and stream warming, but also greater fuel accumulation, fire risk, and evapotranspirative water demand. All measures of fire risk in riparian zones (e.g. fuel loads, stand density, predicted post-fire tree mortality, etc.) are currently significantly higher than in reconstructed historic conditions (Van de Water & North 2011). One study showed that prescribed fire had no lasting negative effects in riparian areas of a northern Sierra Nevada stream (Beche et al. 2005), and scientists are beginning to recommend considering vegetation/fuel treatment in riparian areas as part of landscape restoration strategies (Van der Water & North 2011), taking into account characteristics of riparian systems that influence the natural fire regime (e.g width, presence of pine species, latitude, longitude; etc.).

In addition to fire suppression, water development has significantly impacted the riparian guild in the assessment area. Generally, water development in California has reduced overall flow, reduced seasonality of flow, and shifted flow peak timing of waterways, reducing spring flood pulses and augmenting summer flow (Vaghti & Greco 2007). Water diversion in some areas has been estimated to mimic the effects of the most severe droughts of the previous 2,000 years (Benson et al. 2002). The reduced seasonality of flow, resulting in a lack of episodic disturbance and increased summer water levels, has led to decreased recruitment of pioneer species like Populus through the western United States (Vaghti & Greco 2007). Decreased recruitment is compounded by decreased growth and survival, due to lower overall water flow averages (Stromberg & Patten 1990). Management to mimic natural flow regimes should be emphasized.

Riparian zones are among those areas within the assessment area most heavily affected by non-native species invasions (Schwartz et al. 1996). Salt cedars (Tamarix chinesis, T. ramosissima, T. parviflora) have notably invaded the southern and eastern portions of the Sierra Nevada, and are better adapted to survive water stress and drought conditions than genera like Populus and Salix (Smith et al. 1991; Shafroth et al. 2000; Alstad et al. 2008). Salt Cedar invasion may also increase flammability of riparian systems, interacting with the increase in fire risk through fire suppression to create highly volatile conditions (Alstad et al. 2008). Ailanthus (tree of heaven), introduced in to the US in 1784 from Asia, has impacted mainly the foothill regions of the Sierra Nevada, below elevations of 1,000 meters (3,280 ft) (Schwartz et al. 1996). Russian olive, introduced during the Euro-colonial period, is known to decrease site suitability for cottonwood species, thus further impacting riparian zone composition (Schwartz et al. 1996). Other non-native species that readily colonize riparian ecosystems of the Sierra Nevada include giant reed (Arundo donax), perennial pepperweed (Lepidium latifolium), Himalayan blackberry (Rubus discolor), and purple loosestrife (Lythrum salicaria) (D’ Antonio et al. 2004). Interrelated to the effects of invasive species, are the impacts of grazing, which have been particularly strong in the riparian zones. In addition to affecting overall vegetation density, grazing also directly affects riparian plant species in idiosyncratic ways. Some willow species, such as Lemmon’s willow (Salix lemmoni) and Shining willow (S. lucida ssp. lasiandra) are heavily browsed, while other, less palatable species like Sierra willow (S. orestera) are rarely browsed (Potter 2005). Thus, both grazing and species invasions have likely impacted relative species dominances and community composition within the riparian guild.

Trends

As of the mid 1990s, about one quarter of wildlife species that depend on riparian habitat were considered at risk of extinction (Graber 1996; Kattelmann & Embury 1996), and half of the 32 amphibian species and almost half of the 40 fish species/subspecies found in the Sierra Nevada were endgangered, threatened, or of special concern (Jennings & Hayes 1994; Moyle et al. 1996). Additionally, 85% of Sierra Nevada watersheds are characterized by poor to fair aquatic biotic communities (Moyle & Randall 1996). Today, riparian zones are at greater risk of fragmentation, non-native species invasion, and high severity fire, than historically. An analysis of aerial photographs of about 1/5 of the Sierra Nevada Watersheds showed that 121 of 130 watersheds have clear gaps in the riparian corridor – largely from road/railroad crossings, timber harvest, private lot clearing, livestock grazing, and dam/diversion dewatering (Kondolf et al. 1996). Riparian zones are also among those areas of the Sierra Nevada most impacted by non-native invasive species (Schwartz et al 1996), and altered riparian systems may be especially vulnerable (Parks et al. 2005). Van de Water and North (2011) found that current riparian forests are likely more fire prone than reconstructed historic riparian forests, including greater duff and total fuel loads, predicted surface and crown flame lengths, probability of torching, and predicted post-fire tree mortality.

Anticipated impacts of climate change to riparian ecosystems in the Sierra Nevada include more frequent and severe flash flooding events, earlier peak flows, greater streambed incision, increased evapotranspiration rates, contraction of riparian communities, increased invasions by non-native species, increased stream temperatures, and lower groundwater recharge (Southern Sierra Partnership 2010). Projected future conditions will thus likely exacerbate the current trends of increased fragmentation, invasion, and fire risk, as well as decreased average and minimum streamflows. Finally, as the human population of California continues to grow, so too will demand for water, leading to greater diversion and de-watering within the Sierra Nevada riparian systems (Elmore et al. 2003). The synergistic impacts of declining water table depth, due to human demand[, and increased climate variability, due to climate change, are likely to facilitate further invasion by non-native species (Elmore et al. 2003).

References

  • Alstad, K. P., S. C. Hart, J. L. Horton, and T. E. Kolb. 2008. Application of tree-ring isotopic analyses to reconstruct historical water use of riparian trees. Ecological Applications 18:421-437.
  • Bêche, L. A., S. L. Stephens, and V. H. Resh. 2005. Effects of prescribed fire on a Sierra Nevada (California, USA) stream and its riparian zone. Forest Ecology and Management 218:37-59.
  • Benson, L., M. Kashgarian, R. Rye, S. Lund, F. Paillet, J. Smoot, C. Kester, S. Mensing, D. Meko, and S. Lindstrom. 2002. Holocene multidecadal and multicentennial droughts affecting Northern California and Nevada. Quaternary Science Reviews 21: 659-682.
  • D’Antonio, C.; Berlow, E.L.; Haubensak, K.L. 2004. Invasive exotic plant species in Sierra Nevada ecosystems. In: Murphy, D.D.; Stine, P.A., eds. Proceedings of the Sierra Nevada Science Symposium; 2002 October 7-10, Kings Beach, CA. General Technical Report PSW-GTR-193. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 175-184.
  • Elmore, A.J., J.F. Mustard, and S.J. Manning. 2003. Regional patterns of plant community response to changes in water: Owens Valley, California. Ecological Applications 13: 443 – 460.
  • Graber, D.M. 1996. Status of terrestrial vertebrates. Pages 709 – 734 in Sierra Nevada Ecosystem Project: Final report to Congress, vol. II, Assessments and scientific basis for management options. Davis: University of California, Centers for Water and Wildland Resources.
  • Gregory, S. V., F. J. Swanson, W. A. McKee, and K. W. Cummins. 1991. An Ecosystem Perspective of Riparian Zones. BioScience 41:540-551.
  • Harris, R. R. 1989. Riparian Communities of the Sierra Nevada and their Environmental Relationships. Pages p. 393-398. In: Abell, Dana L., Technical Coordinator. 1989. Proceedings of the California Riparian Systems Conference: protection, management, and restoration for the 1990s; 1988 September 22-24; Davis, CA. Gen. Tech. Rep. PSW-GTR-110. Berkeley, CA: Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture.
  • Harris, R. R. 1999. Defining reference conditions for restoration of riparian plant communities: Examples from California, USA. Environmental Management 24:55-63.
  • Jennings, M.R., and M.P. Hayes. 1994. Amphibian and reptile species of special concern in California. Rancho Cordova: California Department of Fish and Game, Inland Fisheries Division.
  • Kattelmann, R. and M. Embury. 1996. Riparian areas and wetlands. In: Sierra Nevada Ecosystem Project: Final report to Congress, vol. III, Assessments and scientific basis for management options. Davis: University of California, Centers for Water and Wildland Resources.
  • Kobziar, L. N. and J. R. McBride. 2006. Wildfire burn patterns and riparian vegetation response along two northern Sierra Nevada streams. Forest Ecology and Management 222:254-265.
  • Kondolf, G., R. Mathias, R. Kattelmann, M. Embury, and D. Erman. 1996. Status of Riparian Habitat.
  • Loheide, S.P. and S.M. Gorelick. 2007. Riparian hydroecology: a coupled model of the observed interactions between groundwater flow and meadow vegetation patterning. Water Resources Research 43: W07414.
  • Malanson, G.P. 1993. Riparian landscapes. Cambridge University Press, Cambridge. 296 pp.
  • Moyle, P.B. and R.J. Randall. 1996. Biotic Integrity of Watersheds. In: Sierra Nevada Ecosystems Project: final report to Congress, vol. II, Assessments and scientific basis for management options. Davis: University of California, Centers for Water and Wildland Resources, 1996.
  • Moyle, P.B., R.M. Yoshiyama, and R.A. Knapp. 1996. Status of Fish and Fisheries. In: Sierra Nevada Ecosystems Project: final report to Congress, vol. II, Assessments and scientific basis for management options. Davis: University of California, Centers for Water and Wild­land Resources, 1996.
  • Naiman, R. J. and H. Decamps. 1997. The Ecology of Interfaces: Riparian Zones. Annual Review of Ecology and Systematics 28:621-658.
  • Naiman, R.J., K.L. Fetherston, S.J. McKay, and J. Chen. 1998. Riparian forests. In: Naiman R.J. and R.E. Bilby (eds). River ecology and management: lessons from the Pacific coastal ecoregion. New York: Springer, pp 289 – 323.
  • Parks, C. G., S. R. Radosevich, B. A. Endress, B. J. Naylor, D. Anzinger, L. J. Rew, B. D. Maxwell, and K. A. Dwire. 2005. Natural and land-use history of the Northwest mountain ecoregions (USA) in relation to patterns of plant invasions. Perspectives in Plant Ecology Evolution and Systematics 7:137-158.
  • Patten, D. T. 1998. Riparian ecosystems of semi-arid North America: Diversity and human impacts. Wetlands 18:498-512.
  • Potter, D.A. 2005. Riparian plant community classification: west slope, central and southern Sierra Nevada, California. Gen. Tech. Rep. R5-TP-022. Albany, CA: U.S. Department of Agriculture, Forest Service. Pacific Southwest Region. 630 p.
  • Russell, W. H. and J. R. McBride. 2001. The relative importance of fire and watercourse proximity in determining stand composition in mixed conifer riparian forests. Forest Ecology and Management 150:259-265.
  • Schoenherr, A. A. 1992. A natural history of California. Berkeley and Los Angeles: University of California Press.
  • Schwartz, M.W., D.J. Porter, J.M. Randall, and K.E. Lyons. 1996. Impacts of Nonindigenous plants. Pages 1203 –1226 in Sierra Nevada Ecosystem Project: Final report to Congress, vol. II, Assessments and scientific basis for management options. Davis: University of California, Centers for Water and Wildland Resources.
  • Shafroth, P. B., J. C. Stromberg, and D. T. Patten. 2000. Woody riparian vegetation response to different alluvial water table regimes. Western North American Naturalist 60:66-76.
  • Smith, S. D., A. B. Wellington, J. L. Nachlinger, and C. A. Fox. 1991. Functional Responses of Riparian Vegetation to Streamflow Diversion in the Eastern Sierra Nevada. Ecological Applications 1:89-97.
  • Southern Sierra Partnership. 2010. Framework for cooperative conservation and climate adaptation for the southern Sierra Nevada and Tehachapi Mountains, California, USA. Report prepared by The Nature Conservancy, Audubon Society, Sequoia Riverlands Trust, and Sierra Business Council. October, 2010. 275 p.
  • Stromberg, J. C. and D. T. Patten. 1996. Instream flow and cottonwood growth in the eastern Sierra Nevada of California, USA. Regulated Rivers: Research & Management 12:1-12.
  • Stromberg, J.C., R. Tiller, and B. Richter. 1996. Effects of groundwater decline on riparian vegetation of semiarid regions: the San Pedro, Arizona. Ecological Applications 6: 113 – 131.
  • Timmer, K.L. 2003. Troubled Water of the Sierra. Sierra Nevada Alliance. Lake Tahoe, CA, USA.
  • Vaghti, M.G. and S.E. Greco. 2007. Riparian vegetation of the Great Valley. Pages 425 – 455. In: M.G. Barbour, T. Keeler-Wolf, and A.A. Schoenherr (eds), Terrestrial Vegetation of California. University of California Press, Berkeley, CA.
  • Van de Water, K. and M. North. 2010. Fire history of coniferous riparian forests in the Sierra Nevada. Forest Ecology and Management 260:384-395.
  • Van de Water, K. and M. North. 2011. Stand structure, fuel loads, and fire behavior in riparian and upland forests, Sierra Nevada Mountains, USA; a comparison of current and reconstructed conditions. Forest Ecology and Management 262:215-228.


Post-fire Openings

High severity fire can create openings in forests characterized by varying densities of dead trees (snags). Openings vary greatly in size, depending on fire conditions, weather, topography and forest type. Shrub and herbaceous species diversity is often high in these sites, as in any forest gap, but comparatively few species in the Sierra Nevada are true “fire followers” (fire followers require fire heat, ash, or smoke to germinate). Most species responding positively to fire-created gaps are opportunistic species benefitting from increased availability of sunlight, mineral soil, and resources due to removal of the tree canopy and competitors. Examples of true fire followers in the assessment area include conifer species with serotinous cones, such as Pinus attenuata and the cypress species, and shrub species from the genera Ceanothus and Arctostaphylos. Some of the few herbaceous fire followers include species from the genera Emmenanthe, Dicentra, and Nama. Fire suppression reduced the frequency of this habitat across the assessment area, but successional trends toward denser forests dominated by fire intolerant trees led to greater size of postfire openings when they occurred. Over the last 25 years, increases in fire occurrence and severity have resulted in an increasing trend in the number and size of postfire openings.

Other habitats that support uncommon or rare understory plant species, particularly on the eastside or at high elevations in the alpine and subalpine ecological zones include the following.

  • Open (O) – includes those species found in very open, sparsely vegetated and in some cases barren communities, e.g., pumice flats, sandy meadow margins, talus, rock fields, etc.
  • Alkali Flat (AF) – includes species found in highly alkaline soils.
  • Shrub (S) – includes species found in Great Basin and montane shrub communities, e.g., sagebrush scrub, montane chaparral, bitterbrush, etc.
  • Desert shrub (DS) – includes the lower elevation desert shrub types, e.g., Mojave mixed desert scrub, saltbush, spiny menodora, shadscale, etc.
  • Pinyon woodland (PW) – includes species found in pinyon or pinyon-juniper woodlands.
  • Alpine (ALP) – includes those species found in alpine habitats, e.g., alpine fell-field communities.

Ch1_Terrestrial_SpecialHabitats.jpg
Ch1_Terrestrial_Aspen.jpg

Aspen depicted in this map is an overrepresentation because in its current, highly fragmented condition, it does not show up unless the locations are magnified, like we have done here. Other special habitats, including Bristlecone pine and giant sequoia illustrate the very limited distribution of these unique and well-loved plant communities. Recently burned patches can attract and support many species, in particular birds. The pattern of recently burned areas is vastly different in montane forests than the evidence from NRV indicates (Safford 2013). The patches are larger across continuous areas but vastly decreased as smaller patches, particularly within-stand scale (North 2012).

This uniformity, along with absence of low to moderate intensity fire, has resulted in a vast reduction in fine-scale forest complexity. Small, sunny openings, favored by some plants, are relatively rare. Areas cleared of dense, deep leaf and needle litter are uncommon, impeding germination of some types of plants. Shrubs and herbs that need sun or fire to flower or develop vigorous foliage are scraggly or decadent. As a result, understory animals, such as rodents and songbirds, that depend on these plants are decreased. The trend for homogenization and lack of fire to invigorate understory plants will continue. On the other hand, the trend is for larger patches of uniform, early aged, or early seral vegetation to develop after fire. This can be good for the plants and animals in these habitats. The patches are often very large; however, compared to historic patterns, and are widely distributed, limiting movement of species between them, or “connectivity”.

Ch1_Terrestrial_Early_Seral_Veg.jpg


Groups of Bird Species Associated with Specific Habitats

Many other habitat types warrant regular monitoring and assessment to ensure that important ecological functions and processes are continuing to be resilient to stresses and perturbations both natural and anthropogenic. Again, avian monitoring data are uniquely efficient and appropriate measures for addressing the conditions of habitat types such as:

shrub and chaparral

(http://data.prbo.org/apps/snamin/uploads/Managing%20Shrub%20Habitat%20for%20Birds%20in%20the%20Sierra%20Nevada.pdf);

aspen forest

(http://data.prbo.org/apps/snamin/uploads/images/aspen/Managing%20Aspen%20Habitat%20for%20Birds%20in%20the%20Sierra%20Nevada.pdf);

mixed conifer-hardwood

(http://data.prbo.org/apps/snamin/uploads/Managing%20Mixed%20Conifer%20Hardwood%20Habitat%20for%20Birds%20in%20the%20Sierra%20Nevada.pdf);

burned forest

(http://data.prbo.org/apps/snamin/uploads/images/fire/Managing%20Post%20Fire%20Habitat%20for%20Birds%20in%20the%20Sierra%20Nevada.pdf);

meadows

(http://data.prbo.org/apps/snamin/uploads/images/meadows/Managing%20Meadow%20Habitat%20for%20Birds%20in%20the%20Sierra%20Nevada.pdf).

Location data for more than 100 avian species on USFS lands are available via the Sierra Nevada Avian Monitoring Information Network (http://data.prbo.org/apps/snamin/) which include ongoing avian monitoring efforts and are updated yearly with new occurrence data. Species of special conservation concern were assessed through a collaborative effort by California Department of Fish and Game (CDFG) and PRBO Conservation Science (http://data.prbo.org/apps/bssc/) to inform biologists, land managers, and decision makers of the need to protect at-risk birds and of the best methods to do so.


Complex Early Seral Habitat

The Sierra Nevada ecoregion is widely regarded as having one of the most diverse temperate coniferous forest ecosystems in the world and its conservation status is considered critically endangered due to extensive forest fragmentation and other land-use stressors (Ricketts et al. 1999). An extraordinary assortment of vegetation types and diverse forest successional (seral) stages from young to old-growth forests adds to the region’s importance. While much of the conservation attention in the Sierra Nevada has focused on iconic conifers like giant sequoia (Sequoiadendron giganteum) and old-growth forests generally, complex early seral forests (CESFs) created by stand-replacing fire, or lower intensity disturbances such as fires, insects, and windthrow, are underappreciated for their unique biodiversity (Swanson et al. 2010), and, as such, CESFs are not even included as a habitat type in any current vegetation mapping used by the Forest Service (e.g., California Wildlife Habitat Relations). Complex early seral forests occupy sites with forest potential that occur in time and space between a stand-replacement disturbance and re-establishment of a closed-forest canopy. Today's young forests, if resulting from purposeful regeneration harvest or from fire salvage harvest, lack some of the features and characteristics of unmanaged forests.

CESFs are rich in post-disturbance legacies (e.g., large live and dead trees, downed logs), and post-fire vegetation (e.g., native fire-following shrubs, flowers, natural conifer regeneration), that provide important habitat for countless species and differ from those created by logging (e.g., salvage or pre-fire thinning) that are deficient in biological legacies and many other key ecological attributes (Table 1; see also Table 1 in Swanson et al. 2010, Table 1 in Donato et al. 2012). Thus, to distinguish early seral forests from logged early seral, the term “complex” is used in association with early seral produced by natural disturbances. However, as the characteristics that might define 'complex' are not universally defined, purposeful management actions may be able to retain and/or create functionally equivalent environments.

Ch1_Terrestrial_Early_Seral_Veg.jpg

In the Sierra Nevada, CESFs provide habitat for dependent species like Black-backed Woodpeckers and are most often generated by mixed-severity fires, which include patches of varying sizes burned at high severity. There are no inventories of CESFs in the Sierra Nevada. Importantly, there does not currently exist an inventory of CESFs nor have historic and baseline CESF levels been determined in order to assess representation of CESFs in the planning areas.


Photo: Burned forest, Tioga Pass, northern Sierra www-rcf.usc.edu

Table 1. Differences between early seral systems produced by natural disturbance processes vs. logging. For natural disturbances, assume that a disturbance originates from within a late-successional forest as legacies are carried over to disturbed sites during succession. For logged sites, assume site preparation includes conifer plantings but no herbicides. While the illustration below displays woody material, likely collected on a landing, rapid recolonization of plants soon occurs.
Attribute
Regeneration Harvest or Postfire Logged
image 3.jpg
Moonlight immediately postfire logging 2009
Natural Disturbance
image 4.jpg
Star fire 2008 unmanaged (subsequent to one or more growing seasons)
Large trees [snags and some live trees]/downed logs
lower than undistrurbed, but the degee is dependent on harvest design
abundant and widely distributed
Post-fire shrubs and natural conifer regeneration
dense conifer plantings followed by sparse vegetation as conifer crowns close (usually within 15-20 years depending on site productivity)
varied and rich flora
Species composition
highly variable, dependent on planting design and vegetation managment strategies used, deer initially abundant then excluded as conifer crowns close
varied and rich flora, rich invertebrates and birds, abundant deer
Structural complexity
reduced by the removal of dead wood, degree dependent on salvage design
highly complex; many biological legacies
Soils and below-ground processes
variable levels of compaction, dependent on several factors, reduced mycorrhizae, largely dependent on the length of time between tree death and recolonization
complex and functional below ground mats
Genetic diversity
low due to emphasis on commercial species and nursery genomes
complex and varied
Ecosystem processes (predation, pollination)
moderate initially then sparse as conifer crowns close; limited food web dynamics
rich pollinators and complex food web dynamics
Susceptibility to invasives
moderate to high depending on site preparation, soil disturbances, livestock, road densities (see McGinnis et al. 2010)
low due to resistance by diverse and abundant native species and low soil disturbances
Disturbance frequency
dependent on future wildfire effects (unknown timeframe) and/or management decisions (approximately 100 years to several centuries are possible)
varied and complex
Landscape heterogeneity
dependent on design used during reforestation
high; shifting mosaics and disturbance dynamics
Ecological integrity
ldependent on scale and management actions
high
Resilience/resistance to climate change
inherently dependent on the genetic variability of the seedlots used in reforestation; opportunities are significant to attempt to adjust for locally anticipated climate envelopes
varied and complex genomes allow for resilience and resistance to climate change

Fire and CESFs

CESFs in mixed conifer forests are found along the west slopes of the Sierra Nevada at mid elevations (760-1400 m, northern) ascending to higher elevations south (915-3050 m; Chang 1996) and along upper elevations on the east slopes of the range. In drier low-elevation forests, fires are reoccurring and are often low severity, but can have significant mixed-severity effects; mid to upper elevations and mesic forests are characterized by mixed-severity fires that include patches of high severity, and have variable return intervals. (Leiberg 1902, USDA 1910-1912, Show and Kotok 1924, Show and Kotok 1925, Stephenson et al. 1991, Beaty and Taylor 2001, Bekker and Taylor 2001, Nagel and Taylor 2005, Bekker and Taylor 2010, Collins and Stephens 2010, Miller et al. 2012, North 2013).

image 12.jpgimage 13.jpg
Star Fire of 2001, Northern Sierra unmanaged with forbs on left (2008) and natural conifer
re-establishment on right (2012)

Fire is nature’s architect in the Sierra Nevada and it varies widely depending on topography, vegetation, fuels, and climatic factors. Fire regimes most likely to generate CESFs include variable interval and intensity fires in upper montane red fir (Abies magnifica); very-long-interval, stand-replacement fires in mixed-conifer and white fir (Abies concolor) forests; and variable (both short and long interval) stand-replacement fires in Douglas-fir and lodgepole pine forests (Leiberg 1902, USDA 1910-1912, Show and Kotok 1924, Show and Kotok 1925, Stephenson et al. 1991, Chang 1996, Beaty and Taylor 2001, Bekker and Taylor 2001, Nagel and Taylor 2005, Bekker and Taylor 2010, Collins and Stephens 2010,
Miller et al. 2012). Fire, therefore, is an important pathway to CESFs, whether partially, as in low to moderate fire intensities that create fine-scaled heterogeneity (e.g., canopy gaps where succession is reset) at the stand level, or mixed intensity that creates coarse-grained heterogeneity at the landscape level.
image 14.jpgimage 15.jpgimage 16.jpg

Storrie fire of 2000, S. Cascades, unmanaged with snags and forbs on left (2007); Postfire logged portions of Freds fire in the Eldorado National Forest showing lack of nitrogen-fixing
shrubs (center) and presence of Klamath weed (Hypericum perfoliatum) and many readily ignitable, invasive grasses (right) (2011).

Although views on fire are gradually shifting, the Forest Service has attempted to mimic the lower severities of mixed-severity fires mechanically or via prescribed fire in mid- to upper-elevation mixed conifer forests. Management aimed at stopping large fires that historically and currently produce landscape heterogeneity continues through fire suppression as well as widespread mechanical fuel treatments designed to lower the susceptibility of forest ecosystems to high-severity burns. Although there are desired social and cultural benefits in reducing risks to crown-fire damage in iconic forests such as giant sequoia and in the wildland-urban interface, this has come with consequences to CESFs as sequoia, for example, depend in part on mixed- to high-severity fires. In addition, traditional views on high-severity fire as a destructive force that is increasing in frequency and extent have been challenged due to concerns about the importance of post-burned landscapes and data limitations of current fire studies (Brown et al. 1999, Baker and Ehle 2001, Veblen 2003, Baker 2006, Odion and Hanson 2006, Baker et al. 2007, Sherriff and Veblen 2007, Klenner et al. 2008, Odion and Hanson 2008, Baker 2012, Williams and Baker 2012a, Williams and Baker 2012b). Moreover, as described recently in Donato et al. 2012, the "slow, sparse or suppressed tree establishment" associated with CESFs post-fire "may actually accelerate the development of certain forms of spatial complexity that are typically associated only with late-successional forests."

image figure 3.jpg





(Figure 3 in Donato et al. 2012): "Three alternate successional pathways for forest development, showing the relative levels of structural complexity exhibited in each seral stage. In the conventional successional model, both early- and mid-seral conditions are dominated by a relatively even-aged tree cohort, and structural complexity does not arise until the latest stage of development. In the case of analogous precocity, early-successional stands exhibit structural complexity in some ways similar to that in old stands, but canopy closure results in reduced complexity during mid-succession. In the case of homologous precocity, the lack of a tree canopy-closure phase results in a continuity of complexity throughout forest development."






Climate Change And CESF Habitat

Forest fragmentation and climate change have been identified as key issues for forest planning in the Sierra Nevada. Indeed, the climate of the Sierra Nevada is changing and it is unequivocally caused by greenhouse gas emissions from burning of fossil fuels, deforestation and forest degradation, and other factors operating at global and regional scales. In the past century the Sierra Nevada have experienced climate changes (California Energy Commission 2006). Since the 1980s at least, the region has experienced an increase in monthly minimum temperatures of 3° C with effects differing across elevations (Jardine and Long 2013). Annual number of days with below-freezing temperatures in higher elevations is decreasing with more rain and less snowfall mainly in northern latitudes of the ecoregion, while the number of extreme heat days at lower elevations is increasing (Safford et al. 2012, Harpold et al. 2012). Snowmelt occurs 5 to 30 days earlier than decades ago, and peak stream flows have been occurring 5 to 15 days sooner. Some have projected that the onset of fire season could be extended as a result in low- to mid-elevation conifer forests (Safford et al. 2012). Regional climate models project further decreases in mountain snowpack, earlier snowmelt and peak stream flows, and greater drought severity (Overpeck et al. 2012). Such climatic changes are likely to affect the lower elevation ponderosa pine, which is projected to extend upward, and red fir or subalpine projected to lose much of its climate envelope in the coming century. It is unclear how such changes will affect CESFs; however, if fire increases in severity or frequency (Miller et al. 2009 and Miller and Safford 2012—note that these studies excluded severe fire early in their time period of analysis by not using pre-burn vegetation mapping and by omitting some fires), this could provide more opportunities for development of CESFs. This assumes, however, that there is not a proportional increase in post-fire logging, and that fire suppression activities either cannot keep up with the pace of climate-related fire events or prove ineffective due to the increasing influence of climate as a top-down driver of fire behavior. On the other hand, a number of climate models predict decreasing fire activity in these forests—even as temperatures increase—due to increasing precipitation, including summer precipitation and changes in vegetation (McKenzie et al. 2004, Krawchuk et al. 2009).

In addition to climate change, land-use stressors can magnify effects to forest communities and their resistance and resilience to change. For instance, Thorne et al. (2008) documented significant regional changes due to climate and land-use practices resulting in greater levels of disturbance (compared to historical), and substantial (42%) changes in cover types with largest gains in montane hardwood, Douglas-fir, and annual grasslands and biggest losses in low-elevation hardwoods (particularly blue oak, Quercus douglasii), woodland, chaparral, and upper elevation conifers like red fir. Millar (1996) also identified three paramount influences on Sierra Nevada ecosystems: (1) climate change and shifting hydrological patterns; (2) dense forests; and (3) rapidly expanding human populations.

Current Management of CESF Habitat

Post-disturbance management of CESFs has most often included post-disturbance (salvage) logging followed by intense site preparation, including burning of slash piles with associated soil disturbances, reseeding with grasses (often introducing invasive species inadvertently), use of straw-bales and other erosion prevention methods, use of herbicides to reduce shrub competition with conifers, planting with conifer nursery stock, and livestock grazing (Swanson et al. 2010, Long et al. 2013; Table 1). These activities remove or severely degrade CESFs or, at a minimum, can delay or limit the duration of CESFs (Paine et al. 1998, Swanson et al. 2010), contributing to “landscape traps,” whereby entire landscapes are shifted into, and then maintained (trapped) in, a highly altered state as the result of cumulative impacts (Lindenmayer et al. 2011). Thus, given the importance of the Sierra Nevada in general, and the values inherent to CESFs, these forests require proper stewardship, particularly to meet the intent of the new planning rule regarding its emphasis on ecological integrity and to limit cumulative effects of multiple, and often chronic, land-use disturbances in these developing forests.

The new forest planning rule directs the Forest Service to include ecological integrity in forest plan revisions, and, from an ecosystem perspective, managers wanting to implement an ecosystem integrity approach will need to determine historical and current representation of the full range of natural seral stages across the planning area to comply with the forest planning rules emphasis on diversity. Under-representation of any of these stages (from early to mid to late) would reflect shortcomings in ecological integrity approaches, and landscape-scale indices are needed to monitor extent of seral stages and their distributions in forest planning using a combination of baseline (reconstruction) and forecasting approaches (see below). Notably, recent studies (e.g., Fontaine et al. 2009, Burnett et al. 2010, Siegel et al. 2010, Burnett et al. 2011, Siegel et al. 2011, Burnett et al. 2012,
Donato et al. 2012,Siegel et al. 2012a, 2012b) have shown that avian use of post-burn sites is highest if the pre-burn site maintains biological legacies (large trees, snags, down logs) that “lifeboat” important ecosystem functions across seral stages. Thus, from a management standpoint, intense pre- or post-disturbance logging of seral stages can create a long-term successional debt that eliminates legacies essential for maintaining ecological integrity across forest seral stages (DellaSala et al. 2011).

Determining the appropriate representation and distribution of CESFs in a planning area will require “back-casting” designed to reconstruct an historical baseline by combining age-structure reconstructions (e.g., from either FIA plot data or General Land Surveys from the 1800s, see techniques in Baker 2012 and Williams and Baker 2011, Williams and Baker 2012) with fire scar data (although this requires rigorous sampling designs to address variability in tree scaring from fire, and cannot address historic high-severity fire occurrence) to allow reconstruction of historical fire severity. Historical baselines can then be compared to current and future projected conditions under a changing climate in order to determine appropriate levels of CESFs and other seral stages in a planning area. This information is lacking for the Sierra Nevada.

Black-Backed Woodpeckers Exemplify CESFs
image 5.jpg

I believe it would be difficult to find a forest-bird species more restricted to a single vegetation cover type… than the Black-backed Woodpecker is to early post-fire conditions…
Richard Hutto (1995:1050)

No other vertebrate species exemplifies CESF like the Black-backed Woodpecker, a “keystone species” and important primary excavator of nesting holes for itself and other cavity-nesting birds and mammals (Tarbill 2010). It also is one of the most highly selective bird species not only with respect to using burned or otherwise naturally disturbed CESFs, but also targeting specific nesting and foraging snags within a stand – their optimal habitat is dense conifer forest with high basal area of medium and large trees (e.g., mature and old-growth) that has been severely burned, or which has experienced high mortality from beetles, and has been protected from post-disturbance logging (Hutto 2006, 2008; Hanson and North 2008, Tarbill 2010, Siegel et al. 2012). Black-backed Woodpeckers can only effectively use a snag forest for a few years (typically 7 or 8) after it is created, and densities typically decline steeply after about 4 or 5 years following fire (Siegel et al. 2011). Thus, they depend upon the future occurrence of high-intensity natural disturbance to constantly replenish their habitat and are highly sensitive to post-fire logging, which tends to eliminate, or severely degrade, suitable habitat (Hanson and North 2008, Hutto 2008, Siegel et al. 2012 [Fig. 10—near total avoidance of clearcut salvage logged areas in a radiotelemetry study]). Unfortunately, due to lack of habitat protection and fire suppression, Black-backed Woodpeckers have become increasingly rare. For example, these birds in the Sierra Nevada were once described as “numerous” historically but are now considered “rare,” and their optimal habitat there has shrunk to a fraction of historical conditions (Hanson 2012, 2013). Several recent analyses of Black-backed Woodpecker populations in the Sierra Nevada estimate <600 nesting pairs occurring in burned forests, and several hundred pairs or at most several thousand in green forests (Bond et al. 2012; Appendix C Table 7 page 116). The best available science indicates that the overall population in the Sierra Nevada is likely to be below the extinction-risk thresholds of approximately 4,000 individuals (~ equivalent to 2,000 pairs) (Hanson 2013; Traill et al. 2007, 2010). Other research indicates that 7,000 adult individuals are necessary in a population to ensure 99% probability of population persistence over the course of 40 generations—and that the risk of extinction increases dramatically at such threshold population levels if the population is being subjected to “strong deterministic (anthropogenic) factors and habitat destruction” (Reed et al. 2003). Importantly, the remaining pairs have little or no protection on most of the area that they inhabit, and are under mounting pressure from logging practices that prevent high-quality woodpecker habitat from being created on the landscape, or remove it once created.

Historical and current post-fire logging is the greatest threat facing this woodpecker and, more broadly, the burned forest system its presence represents. Moreover, widespread fire suppression, forest restoration thinning, and fire/beetle-prevention thinning projects decrease the potential for new habitat to be created by natural disturbances because those activities are aimed at eliminating mixed- and high-severity fires. The reduction in tree density substantially degrades habitat quality when those thinned stands eventually do burn in a subsequent wildland fire (Hutto 2008). Finally, fire and beetle prevention projects that lower the density of larger trees (which most do) also degrade the older unburned forests used by the Black-backed Woodpecker when burned forest is temporarily unavailable (Siegel et al. 2011).

Post-fire occupancy by Black-backed Woodpeckers also is correlated to fire severity and forest density/maturity, with the woodpeckers strongly selecting areas with the highest densities of medium and large snags (Hanson and North 2008, Tarbill 2010, Siegel et al. 2012).

Given the tight association between these woodpeckers and CESFs, it is reasonable to assume that this species is an indicator (or focal species) of CESFs in the Sierra Nevada. Conifer forest types that are potentially used by Black-backed Woodpeckers in the Sierra Nevada region include mid- and upper-montane conifer forests (Figure 2, panel a). Post-fire habitat since 1984 within these conifer forest types on public lands is scarce (Figure 2, panel b) as it is often logged (private lands were not included since they are usually immediately logged post-fire). Similarly, moderate to high-severity fire habitat, equating to ~ >50% mortality (RdNBR >574—see Hanson et al. 2010) on public lands in the most recent fires for which there are fire severity data (2001-2010, panel c, and the most recent 5 years with fire severity data – panel d) is also rare.

Figure 2. (a) (b) (c) (d)
image 6.jpgimage 7.jpgimage 9.jpgimage 9.jpg

Notably, the new planning rule provides guidance to forest managers to use focal species as a means for maintaining species diversity and wildlife population viability. In particular, the planning rule refers managers to focal species approaches that were recommended by the Committee of Scientists (1999) to provide insights into the integrity of the larger ecosystem to which a particular species belongs. CESFs are a neglected and rare seral stage that provides habitat for dependent species like Black-backed Woodpeckers on the decline because burned habitat is most often logged. Given this woodpecker already is an indicator species of burned forests in the Sierra Nevada, and given its rarity and the threats to its persistence (Hanson et al. 2012, 2013), forest managers should designate this woodpecker as a Species of Conservation Concern and step up monitoring and protection of its CESF in the Sierra Nevada.

CESFs and California Spotted Owls
image 10.jpg

The California Spotted Owl is designated as a management indicator species for all national forests in the Sierra Nevada. Available evidence and knowledge of spotted owl ecology across all three subspecies (Mexican, California, Northern; Bond et al. 2002, Jenness et al. 2004, Clark 2007, Roberts 2008, Bond et al. 2009, Roberts et al. 2011, Lee et al. 2012) show that owls tolerate some degree of moderate to high-severity fire within territories. For example, mixed-severity fire (with an average of 32% high severity) does not reduce California spotted owl occupancy (Lee et al. 2012), and the owl is known to occur and reproduce in territories burned at all fire severities in this region and preferentially selected high-severity fire areas for foraging (Bond et al. 2009). Post-fire logging, however, may precipitate territory extinction (Clark 2007). Consequently, managing CESFs for high levels of ecological integrity would provide important habitat for California Spotted Owls, a species that the Forest Service currently assumes is threatened by high-severity fire.

Photo of California spotted owl on snag in the
McNally Fire area, California

Managing CESFs to Achieve Ecological Integrity

The forest planning rule directs the Forest Service to take an all lands approach to forest management, given that factors influencing a planning area occur at large spatial scales and the emergence of climate change requires coordinated actions across jurisdictions. For instance, Region 5 has been emphasizing management and restoration to achieve ecosystem resilience to climate, and this approach can be integrated with the planning rule’s emphasis on ecological integrity. Because CESFs currently represent a neglected seral stage, managers should account for the following regarding CESFs:
image 17.jpg1 - “Rehabilitation” is not necessary in complex early seral forests. Fire acts as a natural restorative agent for these forests by resetting the successional clock and providing habitat for disturbance-dependent species like Black-backed Woodpeckers. Just because they lack live trees initially and are populated by dead trees, does not mean CESFs require site rehabilitation or are “unhealthy” forests. (See, e.g., Hutto 1995, Shatford et al. 2007, Haire and McGarigal 2008, Hanson and North 2008, Hutto 2008, Donato et al. 2009, Saab et al. 2009, Burnett et al. 2010, Haire and McGarigal 2010, Swanson et al. 2010, Burnett et al. 2011, Collins et al. 2011 [pages 15-23; tables 5 and 6], Donato et al. 2012, Seavy et al. 2012, Buchalski et al. 2013).
2 – Postfire restoration activities may be necessary in early seral forests previously degraded by logging, grazing, and other human stressors. Areas of high ecological integrity (e.g., unmanaged CESFs) can serve as a baseline or reference condition from which to restore degraded areas (e.g., burned plantations), and this should be followed with effectiveness monitoring in an adaptive management sense. Moreover, forest managers can extend the early seral stage in areas that have previously been converted to plantations through creation of canopy gaps (e.g., through snag creation and felling trees to create downed log habitat) and variable-spaced thinning of small trees, providing a mixture of habitat for some closed canopy species and early seral dependents. As trees mature, snags can be created and felled to help meet coarse woody debris requirements for wildlife and increase structural complexity so that subsequent natural fire disturbance can produce a more natural post-disturbance landscape in the future.
3 – Land-use stressors can compromise the integrity of CESFs. Pre-fire “restoration” harvests outside the wildlands-urban interface, as well as post-fire logging, reseeding, conifer planting, erosion prevention, road building, and use of herbicides or insecticides, can severely impact CESFs. (See, e.g., Hutto 1995, 1998, Paine et al. 1998, Hanson and North 2008, Saab et al. 2009, Swanson et al. 2010, Lindenmayer et al. 2011, Burnett et al. 2011, Seavy et al. 2012, Siegel et al. 2012). Livestock grazing can also affect the ecological integrity of CESFs. Further, because prevention of high-severity fire (via mechanical means or fire suppression) is the status quo approach in the Sierra Nevada (Sierra Framework 2004), the importance of high-severity fire patches must be recognized and accounted for in order to conserve the wildlife and habitat associated with CESFs.

Burned forest, Lake Tahoe area
4 –Historical, current, and projected future distributions and spatio-temporal extent of CESFs is lacking. Because data is partly lacking regarding the historical and current status of CESFs, it is necessary to collect more data so that meaningful assessments can be made regarding CESFs. Back-casting and forecasting techniques can be used to make assessments and determine appropriate representation goals in order to maintain ecological integrity and habitat diversity implicit in the new forest planning rule. (See, e.g., Williams and Baker 2011). It is also important to differentiate between the trends and status associated with CESFs – for example, even if there exists a trend towards increasing high-severity fire, the status of CESFs may nonetheless have a different trajectory for a number of reasons, such as a) the burned area may not be complex in the first place (due to its pre-fire status), or b) the burned area’s complexity may be negated by salvage logging or by reforestation efforts. Moreover, the status of CESFs is important separate from trend because even if trend shows an increase in CESF, there may still be a severe deficit of CESF compared to past levels.
5 – Rare species associated with CESFs, especially the Black-backed Woodpecker, should be designated as “Species of Conservation Concern.” By continuing and expanding upon current monitoring efforts, and in partnership with the US Fish & Wildlife Service and species experts, the population viability and habitat needs of rare and important CESF species can be maintained.
6 – Old forest structures as well as dense, old forests should be maintained in order to protect CESF habitat. Large old forest structures take decades to centuries to develop and forest management has otherwise created a successional debt from intensive high-grade logging. Moreover, data indicate that some rare CESF species, such as the Black-backed Woodpecker, rely not merely upon higher-severity fire areas but upon dense, mature/old forests that have recently experienced such fire (Hutto 1995, 2006, 2008, Hanson and North 2008, Tarbill 2010, Siegel et al. 2012). Maintenance of dense, old forests is therefore important in order to provide high-quality habitat when such areas experience mixed-severity fire, or snag pulses from beetles or competition among conifers (Bond et al. 2012).

Literature Cited (Complex Early Seral Forests)

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Connectivity of Selected Ecosystem Types


The ability for species to move throughout a landscape or bio-region, is important for overall population viability and integrity. One key reason is that when local populations become isolated, they become genetically isolated. Then they tend to lose the genetic variability that allows them to respond successfully to changes, such as climate change or new diseases or major changes in habitat. This is suspected for the fisher, since the population in the southern Sierra Nevada is isolated from those to the north and west. Another species that is wide-ranging that is often used to represent the integrity of sagebrush ecosystems is the sage grouse (http://static.sagegrouseinitiative.com/sites/default/files/grsg_rangewide_breeding_density4.pdf). The connectivity of sagegrouse habitat, sagebrush ecosystems, is being widely affected by cheatgrass invasion and subsequent changes in fire regimes and further sage brush changes.

Old forest associated species were identified as an important indicators of ecological integrity because of the long history of reductions in old forest structure following settlement and more recently (Franklin and Fites-Kaufman 1996; USDA 2001 vol. 2, part 3.2 p. 148). Further, species of concern in the Sierra Nevada that preferentially utilize old forests tend to be associated with larger areas with at least some old forest elements throughout (Zielinski 2013, PSW Draft Science Assessment; Keanne 2013, PSW Draft Science Assessment).


Connectivity - Open Space

Connectedness of un-urbanized land (open space), species habitat, and ecological processes are important to biodiversity and ecological integrity (Lindenmayer and Fisher 2006). Connectivity is particularly important to consider at the bio-regional scale (Chapter 1, WIKI). Movement across all lands and different forest administrative units is difficult to consider one small area at a time.

Density and distribution of open space provides a broad picture of areas serving as habitat and movement corridors for individual species. Land where the focus is on resource management and conservation including county, state, and federal governments, land trusts, and conservation easements on private land are more likely to provide “open space” and connectivity for species and habitats, particularly species at risk. Urban areas do not.

In the map below, we assessed “open space” by creating a picture of the density of urbanized areas and private land where management was uncertain into the future. On this map, these areas are depicted as broad zones w with different concentrations, or percent of area, of open spaces and other lands. Broad categories of <5%, 5 to 25%, 25 to 50%, 50 to 75%, and more than 75% private land were mapped. The assessment area is subdivided into six different geographic areas that depict differences in climate and dominant vegetation. On the western half, to the west of the mountain crest, are four geographic areas. The northern geographic area includes the southern Cascade Mountains and areas to the west, encompassing the western one-third of the Lassen National Forest and Plumas National Forests, and Lassen National Park. The central geographic area includes the western half of the Tahoe National Forest and the entire Eldorado National Forest and adjacent private lands. The Stanislaus National Forest, Yosemite National Park and foothill areas to the east make up the central south geographic area. The south geographic area is comprised of the Sierra and Sequoia National Forests, Sequoia & Kings Canyon National Park, and private foothill lands to the west. To the east of the crest, there are two geographic areas. South of Lake Tahoe is the southeastern geographic area, encompassing the Inyo National Forest, the westernmost portion of the Toiyabe National Forest, and intervening Bureau of Land Management lands, and private lands. The entire Modoc plateau including the Modoc National Forest, and extensive Bureau of Land Management and private lands, the eastern two-thirds of the Lassen National Forest, and the eastern half of the Plumas and Tahoe National Forests comprise the northeastern geographic area.

Ch1_Terrestrial_OpenSpace.jpg

The foothills are the most urbanized and have the least potential for open space, most with >75% private land. Beyond the foothills, open space is more continuous in the southern and central portions, with <5% private land, than the northern portions of the bio-region. To the west of Lake Tahoe and north, there are alternating large areas with >75% private with other areas of <25% private land. Large areas on the Eldorado and Tahoe National forests have extensive “checkerboard” lands, with 50% private land, a legacy from railroad land grants. Not all private land is urbanized, and many areas provide for habitat and movement of at least some species.

Some of the foothill private lands are used for ranching, above the foothills for forest management. These private lands can provide benefits of “working” landscapes with connectivity for a wide variety of species, if not all. Recent reintroduction of fisher onto the private timber lands of Sierra Pacific Industry is an example where focused attention on biodiversity and commercial timber objectives can provide for connectivity. Previously, fisher was absent from its former range in the northern Sierra Nevada and southern Cascades, but in the reintroduction area they are expanding and successfully breeding. Time will tell the final outcome.

Intermixed, private land and the roads that go with and between them have impacted species, such as deer, that move seasonally across the same large areas every year. Roads provide important services to society; however, their presence can also negatively influence the movement of species, hydrology, geomorphology, and ecosystem processes on National Forest System lands. There are numerous articles in the peer reviewed literature describing the impacts of roads on the landscape (Chapter 11, WIKI). A significant number of deer are killed along roads, (Romin et al. 1996) and others limited in movement or foraging habitat by fences, houses, or pets. Areas that have a lower proportion of open space have greater and sometimes severe connectivity issues for migrating species like deer.

The ability for species to move throughout a landscape is important for overall population viability and integrity. When local populations become isolated, they also become genetically isolated. They then tend to lose the genetic variability that lets them respond successfully to changes such as a new disease, a change in habitat, or climate change. Connectivity depends on habitat needs and life history of each individual species. It is not practical to look at connectivity for all species, and so for this assessment, we focused on three aspects of connectivity related to habitat types or groups of species of concern: sagebrush (sage grouse), old forest (California spotted owl, and fisher), early seral vegetation (songbirds and some woodpeckers). In particular, the role of fire patterns in affecting connectivity of these habitats and the species associated with them.


Connectivity of Sagebrush Ecosystems


Sage grouse lives in sagebrush habitat, with riparian areas in proximity. Locations in California are restricted to several in the southeast, on the Inyo National Forest and adjacent BLM lands, and in the far northeast, on the Modoc Plateau. Expansion of the non-native, invasive cheatgrass is reducing and fragmenting habitat. Although fire is a natural component of the sagebrush ecosystem, more recently, it can also result in more rapid invasion of cheatgrass.


Ch1_Terrestrial_SageGrouse.jpg

Section in progress—for a map of sage grouse locations and report by BLM please see attached link
http://static.sagegrouseinitiative.com/sites/default/files/grsg_rangewide_breeding_density4.pdf


Early Forest Connectivity

Some species that rely on complex early-seral forest habitat, such as the black-backed woodpecker, may not be able to detect new habitat beyond a certain distance (see, e.g., Hoyt and Hannon 2002). Consequently, like the temporal aspect of post-disturbance habitat, the spatial extent and connectivity of post-disturbance habitat on the landscape is likewise critical to wildlife.

The pattern of recently burned areas is vastly different in montane forests than the evidence from NRV indicates (Safford 2013). The patches are larger across continuous areas but vastly decreased as smaller patches, particularly within-stand scale (North 2012).

This uniformity, along with absence of low to moderate intensity fire, has resulted in a vast reduction in fine-scale forest complexity. Small, sunny openings, favored by some plants, are relatively rare. Areas cleared of dense, deep leaf and needle litter are uncommon, impeding germination of some types of plants. Shrubs and herbs that need sun or fire to flower or develop vigorous foliage are scraggly or decadent. As a result, understory animals, such as rodents and songbirds, that depend on these plants are decreased. The trend for homogenization and lack of fire to invigorate understory plants will continue. On the other hand, the trend is for larger patches of uniform, early aged, or early seral vegetation to develop after fire. This can be good for the plants and animals in these habitats. The patches are often very large; however, compared to historic patterns, and are widely distributed, limiting movement of species between them, or “connectivity”.

Ch1_Terrestrial_PctEarlySeral.jpg


Old Forest Connectivity


We are using three approaches to look at connectivity of old forests or habitat that contains old forest element. First is the distribution of old forest characteristics itself. Second is the distribution of species and suitable habitat for wide-ranging, top trophic level species that are tied closely to at least some elements of old forest. The species we have chosen are the California spotted owl, fisher, and pine marten. Habitat suitablility models and characterizations for these species continue to be a focus of on-going research (http://www.fs.fed.us/psw/publications/reports/psw_sciencesynthesis2013/index.shtml). Some of the key habitat elements identified in ground-based research plots, including large trees and snags, have not been available in remote sensing based maps used to map landscape patterns of habitat suitability (i.e. California Wildlife Habitat Relations Types). This makes it difficult to assess connectivity of the habitat alone without considering the species that uses it. There is new remote sensing data from LIDAR that shows more promise but is only available in limited areas and has not been fully tested in this research application yet.

How does the following discussion of CASPO and fisher differ from what will be in Ch. 5? What habitat info is most pertinent to the Ch. 1 terrestrial ecosystems discussion, and how is it being used here? Focus on connectivity?? Should Ch. 1 be primarily the coarse scale discussion, with fine scale items/spp primarily addressed in Ch. 5, i.e. those elements/spp that are not adequately managed using the coarse filter info?


California Spotted Owl


The Science Synthesis completed by Dr. John Keane of the US Forest Service, Pacific Southwest Research Station, provides a comprehensive review of scientific literature on ecological condition of the California Spotted Owl (Keane 2013). This section is a brief summary of that scientific synthesis. In addition, there is a map of owl locations from the US Forest Service monitoring database. This section should be considered skeletal at this time, pending more time to incorporate the Science Synthesis, the final copy of which was available this week.

The California Spotted Owl is forest carnivore that occurs throughout the Sierra Nevada, on the west slopes in the southern Sierra Nevada and in the central and northern subregions on the western slopes and in some areas transitional to the eastside, drier landscapes north of the Eldorado National Forest. Mixed conifer, white fir, Douglas-fir, yellow pine are the most common CWHR habitat types the owl is found in. But it is also found in red fir at higher elevations, and hardwood, riparian woodlands at lower elevations, particularly in the Southern Sierra Nevada. Research on habitat relations has been conducted primarily at three different scales (Keane 2013).
Insert picture of California Spotted Owl

At the finest scale, nest or roost trees and patches, the owl preferentially selects large, an often the largest, and oldest trees, in a patch (Keane 2013). High canopy closure (local canopy density, as opposed to canopy cover, which is an average density across a stand: sensu North and others 2009, 2012) is associated with the nest or roost trees in these patches or clumps. Owls have poor temperature or thermoregulation, and are thought to prefer the canopy cover to maintain body temperature.

At the intermediate scale, the “core habitat” where the owls are most frequently located using radio-telemetry studies, owls are also associated with patches of high canopy closure and cover (Keane 2013). Average stand diameter tends to be at the high end (>24” dbh) but many stands with medium diameter (12-24” dbh) are also common, since in much of the Sierra Nevada large trees are found scattered or in clumps in these stands as well (Franklin and Fites-Kaufman 1996). Average stand diameter is often not a good reflection of the presence or abundance of large trees used by owls, but is what remote sensing vegetation data that is available characterizes (USDA 2001: p 129-137). On-going research with LIDAR imagry (laser) that can be used to detect presence and spatial patterns of large trees will greatly improve the ability to characterize owl habitat structure at the core area scale. At this time, it is unknown the density or distribution of large trees owls are associated with beyond those utilized by nest and roost trees.

At the homerange, encompassing one to several thousand acres, the size varying with habitat type and prey density, the owls are associated with more varied habitat mosaics (Keane 2013). This is likely because at this scale habitat use is for foraging and the small mammals they prey on use a variety of habitats and habitat elements. For example, wood rats are often found in small patches of shrubs. Deer mice are found in a variety of habitats and use large down wood at least some of the time. Flying squirrels use trees spaced closely (for flying distance) as well as large trees or snags for denning.
A spatial analysis of what habitat is present within nested circles around nest locations is being conducted using the existing vegetation maps shown previously with CWHR types. This is in progress. It can be difficult to interpret what this information represents for spotted owl occurrence and reproduction, since there is some research in this area but generalities are difficult at this time given the variability of habitat conditions they use at these scales, and the lack of mapping of key habitat elements such as large trees.

The California spotted owl is well distributed, depicted by occurrence monitoring by the US Forest Service. Two important cautions when viewing this map need to be considered. First, in order to see the owl locations in a map of this scale, the size of the dot is larger than an actual homerange of an owl, so they look much denser than they are on the ground. Second, in this type of course-filter monitoring, the locations represent individual sitings; there may be multiple sitings in different years of the same individual, figure below.

Although the owl is well distributed, there are some areas of concern that were identified by Verner et al. (1992) that are still of concern today. The bulk of these are in the northern Sierra Nevada where mixed ownership and heavy timber harvest occurred in the 1970’s and 1980’s took place. Today, on privately owned timber lands throughout the west slope of the Sierra Nevada, widespread clearcutting is occurring at a scale approaching 2 million acres. These are short rotation tree cropping systems managed with agricultural chemicals. Additional areas of concern have arisen more recently where numerous, very large fires have resulted in large expanses of non-forested or young forest areas (i.e. portions of the Stanislaus National Forest).

Gradual, but steady population declines over the past 20 years have been observed (Keane 2013). Population trends have been developed using metapopulation analysis of four demography study areas distributed throughout the Sierra Nevada. The next one is planned for late summer. It is unknown whether the declining trend will persist or not. It is unknown what historic distributions or populations were.

There have been few studies on the effect of fires and vegetation management on California Spotted Owl survival and reproduction (Keane 2013). At this time, the effect seems to depend upon the severity and extent of the fire. Low severity fires have been found to have little effect but extensive high severity fires have a great effect (Keane 2013). Most fires are a mosaic of different severities (mixed severity) and in these situations, less is known. Bond et al. 2009, in a radiotelemetry study, found that California spotted owls preferentially selected high-severity fire areas (which had not been salvage logged) for foraging. In addition, Lee et al. 2012 found that mixed-severity wildland fire, averaging 32% high-severity fire effects, did not decrease California spotted owl territory occupancy, but post-fire salvage logging appeared to adversely affect occupancy. Effects on nesting habitat are more straightforward to track than effects on foraging and prey base. Fire effects can include rejuvenation of understory vegetation and increase heterogeneity. Similarly, mechanical treatment can have varying effects depending upon the intensity, extent and changes to different habitat elements.

Distribution of California spotted owl occurances from the US Forest Service monitoring database. [Comment: Need range of dates that these occurence observations encompass]. Two important cautions when viewing this map need to be considered. First, in order to see the owl locations in a map of this scale, the size of the dot is larger than an actual homerange of an owl, so they look much denser than they are on the ground. Second, in this type of course-filter monitoring, the locations represent individual sitings; there may be multiple sitings in different years of the same individual


Ch1_Terrestrial_SPO_sm.jpg
Ch1_Terrestrial_SPO_NRF_sm.jpg
Add explanation of figure above

Trends in Owl Habitat in Relation to Fire

Owls and their associated habitat have developed over time in forested ecosystems characterized by recurrent fire, the foothill, montane, and upper montane forests and woodlands of the Sierra Nevada, southern California, and the southern Cascades. As fire patterns have changed dramatically since European settlement and suppression, vegetation has become denser, more uniform, and fire effects have trended toward larger areas of high severity (van Wagtendonk and Fites-Kaufman 2006). Fires and their effects can affect owl habitat and owls in both negative and positive ways (Bond et al. 2002 and 2009; Lee et al. 2012; Roberts and North 2012; Keane 2013). In addition, salvage logging that occurs post-fire can impact owls (Clark 2007) -- thus, when characterizing fires in regard to owls, it is essential to take into account whether the area was salvage logged (e.g., Moonlight Fire).

Given the uncertainty with what levels of fire severity or what proportion of habitat in different levels of fire severity are important to owl survival and reproduction, we conducted exploratory analysis on a range of values of fire severity and proportion of owl habitat affected. Using the US Forest Service Region 5 Fire Severity Monitoring data (Miller and Safford 2008, Miller et al. 2009) we mapped owl protected activity centers that has the following combinations of fire severity, defined by proportion of tree basal area affected, and area burned. Fires from 1984 through 2010 were included. Although the PAC layer is dated 2001, owls have a high fidelity for nest trees and it is a reasonable assumption that the 2001 PACs are representative of at least many of the owl sites that would have been present in 1984. It could also be an underestimate of owls that were affected between 1984 and 2001, since surveys were less common before then.

Source Information
of Protected Activity Centers
Fire Severity Level
(% Tree Basal Area
affected)
% of Protected Activity
Area Burned at Severity level
2001
>50
>50
Current
>50
>50
2001
>75
>50
Current
>75
>50

Both 2001 and current PAC layers were used because of two reasons. There have been changing land management direction on whether PACs are redrawn or removed. In the 2001 Forest Plan revisions, the direction was “Maintain PACs regardless of California spotted owl occupancy status, unless habitat is rendered unsuitable by a catastrophic stand-replacing event and surveys conducted to protocol confirm non-occupancy”. In the 2004 Supplemental Decision, the direction was modified to “PACs are maintained regardless of California spotted owl occupancy status. However, after a stand-replacement event, evaluate habitat conditions within a 1.5 mile radius around the activity center to identify opportunities for re-mapping the PAC. If there is insufficient suitable habitat for designating a PAC within the 1.5-mile radius, the PAC must be removed from the network.” This makes it difficult to track cumulative effects of fire over time on owl PACs.

These maps show differences between the 2001 and current base as well as some bioregional patterns. Each red dot depicts a PAC that met the criteria for the basal area severity criteria (either 50% or 75%).

Current PACs, 75% Basal Area Severity
2001 PACs, 75% Basal Area Severity
Ch1_Terrestrial_SPO_Current75_sm.jpg
Ch1_Terrestrial_SPO_2001_75_sm.jpg


Current PACs, 50% Basal Area Severity
2001 PACs, 50% Basal Area Severity
Ch1_Terrestrial_SPO_Current50_sm.jpg
Ch1_Terrestrial_SPO_2001_50_sm.jpg

First it is clearly evident that using the 2001 owl habitat base, there are more owl locations affected by fire. We have not sorted out yet, how many owl sites were subsequently removed due to loss of habitat from fire or lack of occupancy from owls with later surveys. The change in direction makes this a complicated question to sort out easily.

Second, there several spatial patterns evident. One is that there have been owl sites affected by high severity fire across more than 50% of the PAC across the entire range of its distribution in the bioregion. Second, there have been the most PAC’s affected in the north and south, particularly the north. The eastern portion of the Sequoia and Plumas have been most affected, in particular the Plumas. This has two potential implications. First, that the drier forests are more susceptible. Second, that single large fires can have big effects to multiple owls in a given area. Two examples are the McNalley fire on the Sequoia National Forest and the other is the Moonlight fire on the Plumas National Forest. The results from the Chips fire that occurred last summer on the Plumas are not tallied yet, but preliminary field observations are that multiple owl sites have also been affected by high severity fire (Keane, personal communication 2/2013). Given the continued trends in fire (area of high severity fire) in the primary owl habitat of mixed conifer, will likely make the number of PACs affected by high severity fire increase over time, and perhaps accelerate. When assessing the impacts of fire on PACs, it is also important to examine the salvage logging that occurred post-fire. For example, salvage logging associated with the Moonlight Fire occurred adjacent to PACs.

Another implication of the trends observed are that the owls that are on the eastern edges of its distribution are particularly at risk and have been impacted. This may be significant in that there may be genetic variation in those owls that is important, particularly in light of climate change and trends toward drier more open forests. This possible genetic variation was noted by Dr. Jared Verner, retired owl scientist, on numerous occasions.

Ch1_Terrestrial_SPO_NRF_AC_sm.jpg

References

  • Miller, J. D., & Safford, H. D. (2008). Sierra Nevada Fire Severity Monitoring 1984-2004. USDA Forest Service, Pacific Southwest Region.)
  • Miller, J. D., Safford, H. D., Crimmins, M., & Thode, A. E. (2009). Quantitative evidence for increasing forest fire severity in the Sierra Nevada and southern Cascade Mountains, California and Nevada, USA. Ecosystems, 12(1), 16-32.
  • Bond, M. L., Lee, D. E., Siegel, R. B., & Ward Jr, J. P. (2009). Habitat use and selection by California spotted owls in a postfire landscape. The Journal of Wildlife Management, 73(7), 1116-1124.
  • Bond, M. L., Gutierrez, R. J., Franklin, A. B., LaHaye, W. S., May, C. A., & Seamans, M. E. (2002). Short-term effects of wildfires on spotted owl survival, site fidelity, mate fidelity, and reproductive success. Wildlife Society Bulletin, 1022-1028.
  • Roberts, S.
  • Lee, D.E., M.L. Bond, and R.B. Siegel. 2012. Dynamics of breeding-season site occupancy of the California spotted owl in burned forests. The Condor 114: 792-802.


Goshawk


Goshawk is another potential focal species that occurs across broad areas, like the spotted owl, fisher, and pine marten, but occurs across a different array of habitats. It occurs in more open habitats on the western slopes and in eastside pine forests, and stands of aspen that the owls do not. Similarly, to the California spotted owl, the continuity of its distribution has also been impacted recently by several large wildfires, particularly in the northern Sierra Nevada and southern Cascades on the Plumas and Lassen national forests and vicinities. The map below, illustrates the location of known goshawk sites compared to ecological fire resilience.

Ch1_Terrestrial_Goshawk_FireRes_sm.jpg


Fisher

The Science Synthesis completed by Dr. Bill Zielinski of the US Forest Service, Pacific Southwest Research Station, provides a comprehensive review of scientific literature on ecological condition of the Fisher (Martes pennanti) (Zielinski 2013). At this time, we are in the process of incorporating additional information from this synthesis. There is also a large body of work underway by the Conservation Biology Institute, under the direction of Dr. Wayne Spencer, on modeling habitat relations at den sites, connectivity of habitat and risks to fire. This information will be incorporated in the trend section in the next few months.

Background

Fishers are carnivores and a large member of the weasel family (Mustelidae) that inhabit conifer, mixed-conifer, and hardwood tree habitats interspersed with forest openings (Zielinski 2013). Fishers require large, old trees, snags, or down logs with small cavities for denning and resting. Denning and resting sites are in localized areas of high canopy cover, but may be surrounded by or interspersed with areas of lower canopy cover. They prey on small mammals in the forest understory or in adjacent openings and typically includes squirrels, mice, voles and deer carrion (Grenfell and Fasenfest 1979; Zielinski 2013). Fishers are long-lived, have low reproductive rates, large home ranges (for carnivores of their size) and exist in low densities throughout their range (Powell 1993; Zielinski 2013).

Chap1_Terr_05.jpg

Average fisher home range sizes in the Southern Sierra Nevada of California.
MEAN MALEHome Range (acres)
MEAN FEMALEHome Range (acres)
Source
SequoiaSequoiaSequoia NF MeanSierraSierra
9,855a7,409d8,63215,3855,421
1,644a1,304d1,4743,5342,945
Zielinski et al. (1997)Zielinski et al. (2004b)Arithmetic MeanThompson et al. (2009)bMazzoni (2002)c
Sierra NF Mean
10,403
3,240
Arithmetic Mean
a Mean of two home range estimating techniques: 95% minimum convex polygon, and adaptive kernel. b Fixed kernel estimates based on 8 male and 17 female territories. Male territories include breeding season movements and may therefore overestimate actual territory size.c 95% Minimum convex polygon estimate d 100% MCP

Fisher Movements

Fishers may be active day or night, but peaks occur at sunrise and sunset (Powell 1993; Zielinski 2013). Assuming two activity periods per day, Powell (1993) estimated fishers may move up to 3.1 miles/day.

In 2003, Weir summarized information about fisher dispersal movements and concluded that they were capable of long distance movements, and that neither major rivers nor other topographic features appear to pose impenetrable barriers (Zielinski 2013). Recent anecdotal evidence shows that rivers may serve as filters, however (Purcell, pers. comm.; in Zielinski 2013). Other considerations such as availability of suitable habitat and prey, avoidance of mortality factors like predators, and the presence of conspecifics (which seems to serve as an attractant), may interact to influence dispersal (Weir 2003; Zielinski 2013). In southern Oregon, juvenile female fishers dispersed from 0 to 10.6 miles, with a mean of 3.7 miles, while males in the same area ranged from 4.4 to 34.2 miles, with a mean of 18.0 miles (Aubry and Raley 2006; Zielinski 2013).

The West Coast Distinct Population Segment (DPS), mapped as an area from northern British Columbia south to the southern end of the Sierra Nevada mountains, is currently a Candidate for listing under the Endangered Species Act (Zielinski 2013). Within this area, there are native populations in British Columbia, far southern Oregon, and California. Reintroduced fisher populations now occur in the Olympic Peninsula of Washington, the Crater Lake National Park vicinity in the southern Oregon Cascades and on Sierra Pacific Industries land in the northern Sierra Nevada, adjacent to the Lassen and Plumas National Forests.

Current Condition and Trends

Fisher distribution in California consists of two native populations, a northern California/southern Oregon population that is distributed over 10 million acres, and a smaller southern Sierra Nevada population occurring over approximately. 2.6 million acres, figure below (Zielinski 2013). These two populations are separated by approximately 240 miles. A recent genetic analysis established that this range contraction, isolation and population decline occurred during the end of the Pleistocene or Holocene epochs and may have been reinforced by mega-droughts in the 9th and 13th centuries AD, pre-dating the European settlement of California (Tucker et al. 2012; Zielinski 2013).

Fisher observation data from the USFS database. Note that dot sizes are much larger than the actual locations, in order to depict them at this scale of map.

Ch1_Terrestrial_Fisher_Obs_sm.jpg



The estimates of fisher population numbers in California are fewer than 500 animals in the southern Sierra Nevada, and from 1,000-4,000 in northern California (CDFG 2010). In the southern Sierra Nevada, preliminary estimates of the USFS long-term monitoring effort suggest that the population has remained stable since 2002-03 (Zielinski 2013). However, it is important to distinguish that the word “stable” here is relative: the population has not significantly declined from baseline monitoring numbers that already indicate the population is threatened with extinction.

Naïve occupancy rates, or the proportion of primary sample units detecting fisher across the entire fisher monitoring area (USDA Forest Service 2006, Truex et al. 2009).
Year
Fisher Detection Proportion
2002
0.268
2003
0.234
2004
0.241
2005
0.252
2006
0.277
2007
0.267
2008
0.238

Spatially explicit, empirical models were employed to create maps of the distribution of fisher populations and habitat in the Sierra Nevada and Cascade mountain ranges (Spencer and Rustigian-Romsos 2012). The general result of the modeling indicates that potential habitat tends to be more fragmented in the northern portion of the interior mountains as compared to southern Sierra Nevada (Ibid).

Uncharacteristically severe wildfire, fire and fuels vegetation management that excessively reduces late seral forest acreages and/or fails to retain adequate representations of late seral habitat elements, rodenticide, disease, and roadkill seem to pose the greatest threat to fisher persistence in the southern Sierra Nevada (Zielinski 2013). Other potential threats identified (predation, climate change, poaching/incidental capture, recreation, and urban development) are considered secondary as our understanding of their possible implications or significance would be more speculative (CDFG 2010).

Current Distribution Relative to Historic

In 1937, Grinnell et al. characterized the range of fishers in California as the northern Coast Range, Klamath Mountains, southern Cascades, and the entire western slope of the Sierra Nevada. Recent genetic analyses, however, shed further light on this. It now appears that a significant but non-quantifiable fisher range contraction, isolation and population decline occurred between the northern California and southern Sierra Nevada populations during the end of the Pleistocene or Holocene epochs which may have been reinforced by mega-droughts in the 9th and 13th centuries AD (Knaus et al. 2011, Tucker et al. 2012; Zielinski 2013). This range contraction pre-dates the European settlement of California. Current sub-population genetic structuring in the southern Sierra Nevada indicates a smaller secondary contraction may have occurred that might be attributable, at least in part, to historic logging practices and other human influences (Tucker et al. 2012; Zielinski 2013).

Historic Logging Practices impact on Fisher Populations

The 250 mile gap in the California fisher populations can be traced to the historic harvesting that originated in the Lake Tahoe Basin and extended westward to the Sierra Nevada of eastern California. All timber resources were manufactured to support the Tahoe Basin mining industry including homes and city buildings. As timber resources were logged out in the Tahoe Basin and the south shore of the Lake going last in the late 1880's, the harvesting pressure moved to areas just west of the Basin in California and then north and south along the Sierra Nevada. By the late 1890's large areas of eastern California had been logged and by 1900, it was reported that the original forests had been cut back from Lake Tahoe some 10 to 15 miles. It was described as "denudation of nearly the entire original forest" (History of Tahoe National Forest: 1840-1940).

Current fisher distribution in California consists of two native populations, a northern California/southern Oregon population that is distributed over approximately 10 million acres, and a smaller southern Sierra Nevada population occurring over approximately 2.6 million acres. These two populations are separated by approximately 250 miles (Zielinski-Science Synthesis 2013).

Population Status

Based on habitat and population monitoring, the size of the southern Sierra Nevada population is estimated at between 125 and 250 adults (Spencer et al. 2011). Monitoring has demonstrated that this population has not declined since 2002 (Zielinski et al., 2012). Populations may have saturated most available habitat on the Sequoia and Sierra National Forests.

There are an estimated 1,000-4,000 adult fishers in the existing northern California population (CDFG 2010). No comprehensive northern California regional monitoring is being conducted.

Based upon a personal communication with Aaron Facka (February 14, 2013), a total of 40 fishers (24 females and 16 males) from the northern California population were translocated onto private timberlands in the northern Sierra Nevada (Butte and Tehama Counties) between 2009 and 2011. As of February 2013, 11 of the original 40 animals are known to have died. A minimum of 34 kits have been born, and the population has approximately 78 percent average annual survival. This survival rate is similar to rates at other study sites in California. Depending upon the estimator and method used, this population is now estimated to have a minimum of at least 40 fishers.

Habitat Status

Generally, habitat is restricted to the western slope of the Sierra Nevada in an elevation band of between 3,500 and 7,000 feet. The status and reproduction of the northern Sierra Nevada reintroduced population would seem to be a preliminary indication that suitable habitat is available, but unoccupied. This zone supports a large number of illegal marijuana plantations and some of the areas at high risk and hazard for wildfire.

Due to the departure from historic fire return intervals in the southern Sierra Nevada followed by large wildfires, there may be less habitat now than prior to European settlement. An opposing theory suggests that the lack of fire has created dense younger forests that provide thermal conditions more favorable to fishers in this hot, dry environment. The only reliable empirical data we have is habitat occupancy and modeling based on demonstrated habitat use. Changes in these metrics should be carefully noted.

Low fisher habitat quality and distribution on the Stanislaus National Forest (Spencer et al. 2008) poses a potential barrier to northward expansion of the southern Sierra Nevada population. Other factors that may also be influencing this lack of expansion are mortality rates from predation and roadkill with secondary effects of anti-coagulant rodenticide poisoning.

Trends Under Current Management

Population and Habitat

In Naney et al. 2012, habitat loss to uncharacteristically severe wildfire was the single most important threat for the southern Sierra Nevada population. It is important to keep in mind, however, that no published studies yet exist that examine how fisher respond to actual fires. The studies that do exist are modeling studies that examine the relative risks to Pacific fishers of mechanical thinning versus wildland fire and base their assessments on the assumption of 90% to 100% tree mortality from fire, while actual mortality rates are far lower. (Odion and Hanson 2006, Odion and Hanson 2008, Collins et al. 2009, Collins and Stephens 2010.)

The second tier included mortality from forest roads, fire suppression activities, vegetation management in the form of fuels reduction and timber production activities (including over- and under-story reduction, decreases in structural elements and vegetative diversity), fragmentation, climate change and forest insect/disease outbreaks. The current trajectory of increasing fire risk and hazard, as well as larger more intense fires will affect fisher habitat via fragmentation (decreasing connectivity), and reduction in overall quality and quantity. This may reasonably be expected to decrease population size (via lower reproduction, recruitment and increased mortality) as well as decrease habitat quality, quantity and connectivity with largely the same effects as above plus decreased fitness and survivorship.

In contrast, the northern Sierra Nevada greatest threats were habitat losses due to reductions in overstory and structural elements, habitat fragmentation and uncharacteristically severe wildfire (Naney et al. 2012). Secondarily, the same panel of experts specified mortality from highways and forest roads, human-related lethal events and activities, urbanization, recreation, reduction of understory and vegetative diversity, climate change and forest insect/disease outbreaks as lesser threats for northern Sierra Nevada. Trajectories are projected to be largely similar to those in the southern Sierra Nevada, but perhaps manifesting at a slower pace due to the larger population size and area of occupancy.

Since the West Coast-Wide fisher assessment (Lofroth et al. 2010, Naney et al. 2012), a new highly-pervasive threat has become evident. California accounts for 70 percent of illegal marijuana production nationwide (Gabriel 2013). Anticoagulant rodenticides applied to remove rodents in illegal marijuana plantations bioaccumulate in the tissues of carnivores, and often interact synergistically with other chemicals such as organo-phosphates. This has resulted in both primary and secondary poisoning effects to fishers, creating potential sink habitats (Gabriel 2013). Examples of secondary effects include reductions in fitness and increased susceptibility to mortality factors such as disease and predation.

Level of Certainty

There has been little disagreement among forest carnivore experts as to the level, immediacy and potential effects of the threats noted above.

Trends in Fisher and Fire Resilience

The restricted distribution of the fisher make it vulnerable to the effects of



Sierra Marten


Current Distribution relative to Historic

Historically, the marten was reported to occur throughout the upper montane regions of the Cascades and Sierra Nevada, but survey results indicate that populations in the southern Cascades and northern Sierra Nevada region are now reduced in distribution and fragmented (Zielinski et al. 2005; Zielinski 2013).

Population and Habitat Status

Available habitat for martens in the southern Cascades and northern Sierra Nevada is isolated and has been reduced in area since the early 1900s (Kirk and Zielinski 2009; Zielinski 2013). Remaining marten populations are associated with sites with the largest amount of reproductive habitat (dense, old forest), the greatest number of nearby habitat patches, and nearby reserved land (land protected from timber harvest (Zielinski 2013).

Evidence from surveys in the central and southern Sierra Nevada (Kucera et al. 1995, Zielinski et al. 2005) suggests that the marten population is well distributed.

Trends Under Current Management

Population

Timber harvest is regarded as one of the primary causes of reduction in marten populations in the western United States (Buskirk and Ruggiero 1994). If the bulk of anticipated thinning is planned considering marten needs for large trees, coarse woody debris and dense overstory (>69%; Ellis 1998) canopy and it occurs from below, population decreases from this threat can be minimized. Unless overly dense forest conditions are treated, habitat will continue to be lost to wildfire. Loss of habitat from any cause results in lowered marten population density.

Habitat

Forest thinning for any reason poses the greatest direct threat to marten habitat, with thinning from below having the least impact (Zielinski 2013). Habitat loss due to wildfire is also a great threat. Since the marten elevational distribution of ~4,500 to 10,500 ft. with much in the red fir zone is higher than that of fishers, there may be less thinning to reduce fuels and fire hazard.

Level of Certainty

It is difficult to assess trade-offs between the threat of habitat loss due to vegetation management vs. wildfire with any certainty. Both are likely to result in downward pressures on marten populations and habitat in the most immediate future, while resulting in gains over the long term.


Landscape Mosaics of Old Forests


There are few sources of geographic information on the spatial distribution of old forests, and in particular the locations and densities of key old forest elements of large trees, large snags, and large logs. This is largely due to the fact that only recently have remote sensing data, such as LIDAR, has been available to map large trees. But it is still cost prohibitive for large areas. Consequently, the large, landscape mosaic maps of old forests developed for SNEP using expert knowledge in 1996 is displayed below. There were some updates for fires up to 2000. The second source of information was from on-going modeling of quality and suitable habitat for fisher and marten by the Conservation Biology Institute. This work is in progress, but the authors have graciously given us permission to display here.

Old forest ("LSOG") map from Sierra Nevada Ecosystem Project (Franklin and Fites-Kaufman, 1996. These are "series normalized" ranks, ranging from 0 (none) to 5 (high concentration). The criteria for what is old forest in the series normalized varies with the dominant forest type. For example, in montane westside forests, trees >40" dbh are considered. In subalpine forests, trees >18" or sometimes smaller, with sparse canopy would be considered high quality. This map does not incorporate fires since 1996, any tree mortality or harvests. This map only represents forests on public lands (all ownerships), not private.


Ch1_Terrestrial_LSOG_sm.jpg

Trends in fire across the bioregion have implications for connectivity of wide ranging species of concern, like the spotted owl. There has been a disproportionately high concentration of owl nest sites impacted by high severity fire in the north, primarily from several large fires that burned under very hot, dry and often windy conditions in steep terrain (e.g. Moonlight and Chips fires). Some birds, early seral or snag favoring, respond favorably to these fires (see previous focal species discussion; Chapter 1, WIKI). However, many distributed, smaller large severity patches would provide better connectivity across the bioregion, than several large, high severity patches in limited areas. A few, high severity fires, do not contribute as much to bioregional connectivity for early seral species and are detrimental to connectivity for late-seral, forest species.


A substantial proportion of key landscape areas of aquatic conservation concern, critical habitat for yellow-legged frogs and old forest mosaics (Franklin and Fites-Kaufman 1996) also have low fire resiliency. These are areas where concentrations of uncommon, ecologically important species and habitats are in otherwise good ecological condition.

Ch1_Terrestrial_Aquatic_FireRes_sm.jpg

Ch1_Terrestrial_LSOG_FireRes_sm.jpg

Ongoing efforts by the Conservation Biology Institute can be found at their website at
http://d2k78bk4kdhbpr.cloudfront.net/media/reports/files/Report_Decision-support_maps_for_Sierra_Nevada_carnivores_8_21_12.pdf


Potential Trends with Climate Change


Note: this section is in progress with many additions underway to reflect on-going current efforts, such as by the interagency California Conservation group, the national park service, researchers and others.

An interagency effort is underway to characterize and evaluate potential trends in vegetation and biodiversity in California. As part of this, projects of changes in vegetation have been developed with potential climate change (http://californialcc.org/, http://californialcc.org/projects/vulnerability-assessments, http://ecoadapt.org/programs/adaptation-consultations/calcc, http://goo.gl/Lg3Bn). There is uncertainty about what the changes in climate will be and how those changes will affect vegetation, other living things directly and indirectly through changes in habitat, environmental tolerances and fire. There is general agreement that changes are and will occur but not on how much or where. The common view overall is that at the boundaries between different vegetation types, such as the lower elevation of ponderosa pine and mixed conifer or red fir or subalpine, that there will be the most changes. In general, it is predicted that there will be an upward migration of vegetation types or species and shrinking of higher elevation or upper montane (i.e. red fir) and subalpine zones. It is unknown how fast these trends will occur.

Maps of current vs. projected future habitat type distributions and zonation analysis of priority avian conservation species targets. Maps were taken from the California LCC Environmental Change Network (http://data.prbo.org/apps/ecn/).
Chap1_Terr_08.jpg

Potential Trends with Fire



Potential Trends with Human Demographic and Land Use Trends


Under construction will likely be covered as an integrated discussion in the actual assessment document - rather than these topical papers that are broken out by different areas.

Moving Beyond Vegetation Sensing to Ensure Protection and Sustainability of Biodiversity--The Fine Filter Approach


One of the fundamental and ongoing debates in forest management is centered on the scales and intensity of monitoring wildlife species to assess responses to changes in the environment. In a recent publication in the Journal of Wildlife Management(Schultz et al. 2013) (add Link), several experts in wildlife conservation planning express concern of the Forest Service’s historic reliance on what is termed “coarse filter” approaches to monitoring wildlife species. The authors state, “Research indicates that the coarse-filter approach is unlikely to provide a reliable basis for multi-species conservation planning, (Cushman 2008), only limited testing of the approaches validity has occurred (Noon et al. 2009), and the monitoring of a select group of species using a fine-filter approach is necessary to determine the efficacy of coarse-filter approaches (Committee of Scientists 1999, Flather et al. 2009). A recent review of the degree to which coarse-filter models can be used to infer animal occurrence concluded that ‘..the observed error rates were high enough to call into question any management decisions based on these models’ (Schlossberg and King 2009).” The authors go on to state that the basic assumption that habitat is a valid proxy for species health is at best a risky stretch and at worst a weak and incomplete picture of the health, functioning and diversity of a particular ecosystem.

Another monitoring approach, also largely driven by expediency, postulates that species surrogates (indicator species) are adequate proxies for suites of species associated with various vegetation types across a landscape. In recent research (Cushman et al. 2010) examined 72,495 bird observations of 55 species across 1046 plots across 30 sub-basins and found “few significant indicator species relationships at either scale” where there was a presumed association.

In PSW-GTR-237, Managing Sierra Nevada Forests (2012) authors Malcolm North and Patricia Manley suggest that “coarse filter” approaches such as the California Wildlife-Habitat Relations model “generally fail to account for the different spatial and temporal scales at which species may respond to forest conditions or assess habitat features other than large trees and canopy cover.”

The Sierra Nevada Framework Environmental Impact Statement (2001) habitat projections for old forest attributes are an example of the coarse filter approach. Old forest habitat--large trees greater than 50 inches in diameter and large snags--were projected to increase significantly over a 140-year time scale. Oaks modeled to 60 years showed similar results. Yet, species monitoring has demonstrated that the California spotted owl, one of the key sensitive species of management concern closely tied to these habitat values, is currently experiencing a declining population trend (Keane 2013). The information regarding declining spotted owl trend was the result of fine-filter monitoring via a long-term spotted owl research project. If managers (and conservation advocates) were to rely simply upon the optimistic habitat projections in the 2001 Framework Plan and EIS (which the conservation community actively supported) we would be flying blind in what looks like an increasing grave situation for the owl’s survival.

Fine-filter monitoring approaches are less likely to oversimplify how animals use habitat and are more likely to capture effects of fine scale habitat fragmentation, predator-prey relations, behavioral responses to changed conditions, the value of understory diversity and snags and downed wood, landscape scale relationships or connectivity and spatial and temporal patterns of detection and non-detection.

In the new Forest Service Draft Directives, FSH 1909.12, Chapter 30 Monitoring, Section 32.12 “Selecting Monitoring Indicators,” stresses the financial feasibility, practicality, measurability and relevance to key monitoring questions. Section 32.13 establish eight monitoring indicators for tracking ecological conditions and progress toward desired conditions, plan objectives and important trends. Included in the directives are indicators to assess ecological conditions and status of focal species that are tied to ecological conditions.

These are generally coarse filter metrics that will be further defined in the specific revision of forest plans, including the Inyo, Sierra and Sequoia National Forest early adopter forests in California. Chapter 20 of the new Directives address the need for specific fine-filter standards when more general ecosystem indicators are not specific enough to address at-risk species needs such as nest tree protection or culverts allowing proper fish passage.

The National Forest Management Act requires the Forest Service to provide for a diversity of plant and animal species and not simply a range of ecological conditions that may or may not support diversity. The new Forest Service Planning Rule and its Directives system must ensure diversity of plant and wildlife species is maintained. The Forest Service’s obligation cannot devolve into a suite of invalid assumptions, ruled by efficiency which ultimately fail to meet the intent of the NMFA and the public’s expectation that Forest Service land managers will examine closely and rigorously the effects of management and changing conditions on the land.


Ecological Integrity - Restoration Pace and Scale

What we leave on the land, not what we take away is the essence of ecological restoration. Ecological restoration embraces a revised perspective on how lands are managed in two key ways. One is restoring ecosystems where they have been degraded from past management and are not providing for plants and animals that depend upon them. Second is ensuring the resilience, or sustainability, into the future with trends in climate, drought, and fire. Only with resilience, can forest and water ecosystems provide habitat for plants and animals, the plants and animals themselves, and ecosystem services such as water, recreation, fire resilience, and carbon regulation—all part of ecological integrity.

Many of the landscapes, distribution of plants and animals, and fire patterns have been drastically altered by human management in the last century. Some of the forests, meadows, and streamside areas have been degraded. Putting out fires was a good strategy for saving individual trees, but made forests overcrowded and susceptible to large, high intensity fires and vulnerable to and drought, insects). Large trees, and especially fire and drought resistant pines were selectively harvested, reducing habitat (food and shelter) for some specialist animals, plants, and fungi.

Intensive grazing in the late 1800’s and early 1900’s degraded meadows and resulted in streams that sunk far below natural levels (incised), removing natural flooding that sustained water-loving (wetland) plants and animals. Roads and trails were built through meadows and streams with little thought of erosion sensitive design. Extensive water development, including diversions and dams, supported a nationally important agricultural industry and growing cities and communities in the state but at the expense of natural flooding cycles that sustained stream and riverside and water plant and animal communities.

Invasive plants and animals rode the wave of these uses, taking advantage of the fur of livestock or areas cleared with logging or grazing to gain entry. Once there, they often expanded and invaded other areas, often dominating and displacing native plants and animals. Humans aided in the introduction and spread of numerous, non-native plants and animals that compete and often entirely displace native plants and animals, such as star-thistle, cheat grass, brown cowbird, or barred owls, that change fire patterns, disrupt nesting or breeding and imperil more of these species.

Management of forests, meadows, rivers, and lakes in recent decades has been more careful and scientifically based, but has not kept pace with changes in climate, fire, and sustaining needs of people. Weather is getting hotter and drier, increasing the intensity and length of fire season. Forests continue to get more overcrowded and demands for recreation opportunities in the bioregion grow. A steadily growing presence of people in towns, and scattered homes have broken up the continuity of plant and animal habitat, impeding movement of wide-ranging ones like deer, fisher, or mountain lions. Other plants and animals, with more constricted living areas (distributions) have had habitat removed all together. The rich diversity of plants and animals, that draw many people to live and visit the area have an increasing number that are considered threatened or vulnerable to future changes in weather, fire, or development.

Over time, particularly over the last 50 years, public land management agencies, such as the US Forest Service, and state agencies responsible for managing the forests, grasslands, wetland, and water ecosystems have tried to keep up with the changing ecosystem conditions and human needs. As science increases our knowledge, using a scientific basis is always a goal. Understanding the complexities of natural ecosystems and how to balance human uses will likely always remain beyond our reach to entirely capture the entirety of them and science is always changing, building upon past knowledge and refining or sometimes entirely changing ideas. In the meanwhile, ecosystems and human needs go on and the important task of sustaining the legacy for future generations and providing for current needs of both natural ecosystems and humans is a central goal. In the past several decades, as fires have become more uniformly intense , and climate has become hotter and drier (Chapter 3, WIKI), there is a need to increase the speed (pace) and breadth (scale) of management that restores forest (North, Collins and Skinner, Keane, Zielinski 2013-Science Synthesis), shrub, grass, and water ecosystems (Long et al., Hunsaker et al. 2013-Science Synthesis) so that they can withstand (resilient) these changes and still provide for native plants and animals, and all of the other services ecosystems provide such as water (State ? meadow restoration program), recreation, and rural community sustenance.

Specific strategies for increasing the pace and scale of ecosystem restoration have been identified recently by a number of scientific efforts. A number of them are summarized below, with emphasis on those that are important across large areas of the bioregion, improve or maintain,major aspects of ecological integrity, are economically and socially sustainable, and are most within reach with current resources.

Past and current management strategies for land-based (terrestrial) and water-based (aquatic) ecosystems have focused on averages or “normal” conditions. An example of this is from flood zones. Typically, zoning is focused on the average “100” year flood line. But when the “200” year flood comes, houses get flooded or levies get ruptured. Similarly, fire and forest-management have “high” fire or drought conditions, or the 90th percentile weather. With longer, hotter fire seasons already here (Westerling 2006), and increasing early and more erratic flooding and alternatively very dry years (Null and Viers 2012), this “normal” average approach is ineffective and will be more ineffective in the future. This tendency to manage for the “normal” condition, rather than the less likely but high impact events is human nature (Taleb 2007) and called the “Black Swan” syndrome. We don’t expect a black swan, and when we see one, are usually taken aback. Planning for the present and near future in the bioregion needs to consider that “normal” is changing for water, fire and drought. This can be done in several ways.

Water is of vital importance to Californians and numerous meadow and aquatic ecosystems, and these ecosystems have been identified as amongst the most vulnerable to climate change (Null and Viers 2012; Chapter 1, WIKI; Hunsaker et al. 2012; Sierra Conservancy 2012b; NPS 2013). Restoration of meadow condition has been identified by the State of California as a priority for maintaining and improving future water storage with drying climates. This will also benefit numerous species at risk from shrinking meadow habitats with warming climates (TACCIMO 2013). I second important recommendation was that In a white paper prepared by the UC Davis for the California Energy Commission, is that scientific models used to regulate water storage and releases from dams and diversions be changed from one based on “water year type” where climates are considered stationary to one where changes are assumed. Critically dry water years are expected to be 8% and 32% more likely in the northern and southern portions of the bioregion in the latter half of the century and meadow restoration and consideration in water development plans (FERC relicensing 4E conditions) that include requirements for aquatic ecosystem conservation.

For forest resiliency to fire and drought, several broad restoration strategies will be important in achieving sustainability of plant and animal habitat, as well as stability of carbon cycling, reducing poor air quality from large, high intensity wildfires, and ensuring the capacity to maintain forest resilience to future climate changes. First, much more extensive areas of the landscapes, especially forested need to be restored to more resilient conditions (Chapter 1, 3 WIKI; Collins and Skinner 2012, Science Synthesis).

Currently a small fraction of the landscape is treated, typically less than 5% and has not been effective in restoring forests so that when intense fires burn through during the hottest and driest, or windiest weather, that habitat and ecological integrity is maintained. While there is repeated documentation of strategically placed fuel treatment zones reducing fire intensity and spread, and improving effectiveness of firefighters, increasingly this only affects a small portion of the landscape. In addition to these strategically placed areas of intensive management, reduction of forest density and increasing forest patchiness or “heterogeneity” across 2/3 or more of the landscape in the lower and middle elevations (montane, ponderosa pine and mixed conifer) will be needed to effectively change fire intensity and tree kill to levels that provide for ecological integrity (carbon stability, connectivity, habitat, and fire process). Current, widely used fire prediction models do not account for the more extreme (vs average) explosive, fires that are becoming increasingly common (Brown et al. 2004, Westerling et al. 2006, Westerling and Bryant 2008, Westerling and Bryant 2008)). They still provide useful planning tools but target weather needs to be changed from 90th to 97th percentile (dry to very dry) conditions, and other tools or strategies to evaluate more explosive fires need to be addressed, even if qualitatively. One tool is currently in development by Westerling and others as part of a USDA research grant, that links the probability of very large, very severe fires with changing climate and proportion of the landscape in fire resilient states (condition classes – Barrett et al. 2010) (Westerling, personal communication).

Although the landscape nature of fires and wildlife habitat connectivity have long been recognized in national forest and other land management plans in the bioregion, they often have great detail on individual species sites, or forest stand characteristics over the short-term in guiding management. Lack of focus on the “big picture” over the landscape, distribution of species and resilience in time greatly limits reaching goals of sustainability of ecological integrity. One approach currently in progress, are landscape “adaptive management” projects, eg. Last Chance and Dinkey Creek (USFS 2010, 2011). Some have proposed distributing these across more large landscapes (Aplet and Gallo 2013). The scope of the changes needed to address changes in large fire intensity and resilience to drought will require even more extensive adaptive management, with rapid, real-time, focused monitoring and adjusting. Trends in larger, more frequent fires with early spring snowmelt are already occurring (Westerling, personal communication, in progress) and may have great impacts before large, formal adaptive management experiments are completed.

Ch1_Terrestrial_SnowMelt_sm.jpg

There are several strategies for improving the pace of restoring and maintaining forest resiliency. One is to emphasize partnerships to help offset costs for restoration treatments that reduce potential air pollution emissions and benefit carbon storage stability. Fire resilient forests provide more resilient carbon storage (North 2012, Science Synthesis; Vaillant et al. 2013) in dry, fire prone forests. Placer County has developed and is testing and innovative way to utilize partnerships amongst counties, the US Forest Service and private contractors, to use mechanical thinning and biomass removal to restore forest density and composition, while reducing potential air pollution during intense wildfires and offset costs (Springsteen et al. 2011). Stewardship contracts are one vehicle that that US Forest Service is increasing use of to enhance capacity for such innovative projects. Rapid expansion of these would allow for their more widespread application. Stewardship contracts are also a vehicle for increasing the opportunity for tribal involvement in restoring forest resiliency and ecological integrity through traditional ecological practices (TEK).

Traditional ecological practices include a wide variety of active management from reduction of forest and vegetation density through varied mechanical or hand treatments or fire to restore ecosystem conditions that provide and enhance materials and areas important to tribal cultures (Lake 2012, Science Synthesis; USFS 2013 Forest Restoration Strategic Plan). Another way to incorporate TEK and enhance capacity and increased pace of restoration is to incorporate tribal fire crews into roving, “strike teams”, specializing in fire restoration.

Economic and organizational efficiency is restoration is paramount. The need is vast but money and people are increasingly limited to achieve restoration needs that are more imminent. Strike teams of fire management crews that specialize in prescribed fires or burning for ecological integrity on managed wildlfires is a critical way to achieve two key aspects of restoring ecological integrity. Fires serve to restore large areas with relatively cheap tools, that are often less economically viable or more controversial for mechanical treatment, and restores fire as a process where fire deficits are widespread. These strike teams can also specialize in collaborative work with local fire managers, air quality and air pollution control boards that are part of successful, large projects to restore fire, and reduce future emissions and fire intensity (Vaillant et al. 2013). This approach has been successfully applied on the Sequoia National Forest and could be expanded. “Burn bosses” qualified to lead these teams are in short supply and sharing them amongst forests and with shared firefighting duties has been a limiting factor. Special burn strike teams would address this limitation.

Similarly, there are limitations on capacities needed to plan and implement more extensive thinning and biomass treatments to improve forest resiliency to high intensity fire and drought and restore ecological sustainability. Retirements and declining budgets have greatly reduced the number of experienced, high expertise persons that design and implement mechanical thinning and biomass treatments. This is particularly critical with increased requirements for ecologically sensitive treatments and effective utilization of new and evolving equipment. Similar to “strike teams” of fire restoration crews, mechanical forest restoration teams are also needed to increase the pace and scale of ecosystem restoration.

Another limitation is the infrastructure for biomass and thinning treatments. Originally, there was a large distributed infrastructure of mills developed to process large quantities of large and medium logs that were harvested from private lands for commercial timber harvest. As priorities changed and shifted to ecosystem management, a large number of the mills closed, particularly in the southern portion of the bioregion. While some were retooled to handle the smaller diameter trees that came from forest health thinning projects, some were not. Plants that take biomass removed from even smaller trees and shrubs, “ladder fuels” that carry fire from the ground up into the tops of trees, are even more limited in number and extent. This makes it uneconomical to apply these restoration tools, important for fire and drought resiliency, and many forests are left untreated as a result. Collaborative projects with counties, Department of Energy and private industry are one way that Placer County is working to remedy the situation. More collaborative efforts like this are urgently needed. While energy from biomass is more expensive at this time, increasing utility rate collections for these energy sources by 11 cents a kilowatt (Western Governors Association 2006) as proposed by the Placer County group (Springsteen et al. 2011) would address the problem as well as improve within-state energy resources.

In summary, as stated in the national US Forest Service Restoration Strategic Plan “Increasing the pace and scale of restoration of the Nation’s forests is critically needed to address a variety of threats—including fire, climate change, bark beetle infestation, and others—for the health of our forest ecosystems, watersheds, and forest-dependent communities.“

Ch1_Terrestrial_ClimateVeg_sm.jpg


Appendix – CWHR Classification Groupings


Combined cover type

Combined size class

Appendix - Wildlife Species Groups and Proposed Habitat/Ecosystem Types


Proposed Habitat/Ecosystem Types
Species
TACCIMO
CA Wildlife Strategy
USFS

Foothill Chaparral
Fox Sparrow










Oak Woodland
Blue Oak
x




Black Oak





Mule Deer





Pallid Bat




Burned Forest






Black-backed Woodpecker
x



Early Seral Forest
Mountain quail





Deer (subspecies?)




Plantation -- Conifer Agriculture
White breasted nuthatch










Mid-Seral Forest
Mountain quail










Forest with Snags
Hairy Woodpecker
















Late-Seral Open Forest

















Late-Seral Varied Canopy Forest (Closed, Patchy and Open)
Giant Sequoia groves
x




Northern Goshawk
x




California Spotted Owl
x




Flying Squirrel
x




Sierra Nevada Red Fox
x




Pacific Fisher
x




Marten
x









High Elevation Woodlands and other communities (e.g. grasslands, rock scree, cliff)
Bristle Cone Pine





Foxtail Pine





Limber Pine





Whitebark Pine





Western White Pine





Sierra Nevada Bighorn Sheep





Gray-headed Pika




Sagebrush
Greater Sage Grouse





Swainson’s hawk




Other Eastside ?













References



Additional references to consider on terrestrial ecosystems (plant communities)/climate change (reviewed in TACCIMO:http://goo.gl/Lg3Bn)):

Plant Communities - general
  • Aber, J. D., Goodale, C. L., Ollinger, S. V., Smith, M., Magill, A. H., Martin, M. E.,…Stoddard, J. L. (2001). Forest processes and global environmental change: Predicting the effects of individual and multiple stressors. BioScience, 51(9), 735-751.
  • Alpert, H. & Loik, M. E. (2013). Pinus jeffreyi establishment along a forest-shrub ecotone in eastern California, USA. Journal of Arid Environments, 90, 12 – 21.
  • Barbour, E. & Kueppers, L. M. (2011). Conservation and management of ecological systems in a changing California. Climatic Change, DOI 10.1007/s10584-011-0246-y, 1-
  • Klausmeyer, K. R., Shaw, M. R., MacKenzie, J. B. & Cameron, D. R. (2011). Landscape-scale indicators of biodiversity’s vulnerability to climate change. Ecosphere, 2(8), 1 - 18. doi:10.1890/ES11-00044.1
  • Kueppers, L. M., Snyder, M. A., Sloan, L. C., Zavaleta, E. S., & Fulfrost,B. (2005). Modeled regional climate change and California oak ranges. Proceedings of the National Academy of Sciences, 102(45), 16281-16286.
  • Lenihan, J. M., Drapek, R., Bachelet, D., & Neilson, R. P. (2003). Climate change effects on vegetation distribution, carbon, and fire in California. Ecological Applications, 13(6), 1667-1681.
  • Lenihan, J. M., Bachelet, D., Drapek, R., & Neilson, R. P. (2006). The response of vegetation distribution, ecosystem productivity, and fire in California to future climate scenarios simulated by the MC1 dynamic vegetation model. California Energy Commission, PIER Energy-Related Environmental Research Program, CEC-500-2005-191-SF, 25pp.
  • Lloret, F., Penuelas, J., Prieto, P., Llorens, L., & Estiarte, M. (2009). Plant community changes induced by experimental climate change: Seedling and adult species composition. Perspectives in Plant Ecology, Evolution and Systematics, 11, 53-63.
  • Loarie, S. R., Carter, B. E., Hayhoe, K., McMahon, S., Moe, R., Knight, C. A., & Ackerly, D. D. (2008). Climate Change and the Future of California's Endemic Flora. PLoS ONE 3(6), e2502. doi:10.1371/journal.pone.0002502
  • Lutz, J. A., Van Wagtendonk, J. W., & Franklin, J. F. (2010). Climatic water deficit, tree species ranges, and climate change in Yosemite National Park. Journal of Biogeography, 37(5), 936-950.
  • Moser, S., Franco, G., Pittiglio, W., Chou, W., & Cayan, D. (2009) The future is now: An update on climate change science impacts and response options for California. California Energy Commission Public Interest Energy Research Program, CEC-500-
  • Rehfeldt, G. E., Crookston, N. L., Saenz-Romero, C. & Campbell, E. M. (2012).North American vegetation model for land-use planning in a changing climate: a solution to large classification problems. Ecological Applications, 22 (1), 119 – 141.
  • Rice, K. J. & Emery, N. C. (2003). Managing microevolution: restoration in the face of global change. Frontiers in Ecology and the Environment, 1 (9), 469 – 478.

High elevation
  • Bunn, A. G., Waggoner, L. A. & Graumlich, L. J. (2005). Topographic mediation of growth in high elevation foxtail pine (Pinus balfouriana Grev. et Balf.) forests in the Sierra Nevada, USA. Global Ecology and Biogeography, 14, 103 – 114.
  • Diaz, H. F. & Eischeid, J. K. (2007). Disappearing "alpine tundra" Koppen climatic type in the western United States. Geophysical Research Letters, 34 (L18707), 1-4.
  • Eckert, A. J. & Eckert, M. L. (2007). Environmental and ecological effects on size class distributions of foxtail pine (Pinus balfouriana, Pinaceae) in the Klamath Mountains, California. Madrono, 54(2), 117 – 125.
  • Graham, E. A., Rundel, P. W., Kaiser, W., Lam, Y., Stealey, M. & Yuen, E.M. (2012). Fine-scale patterns of soil and plant surface temperatures in an alpine fellfield habitat, White Mountains, California. Arctic, Antarctic, and Alpine Research, 44(3), 288 – 295.
  • Hurteau, M., Zald, H. & North, M. (2007). Species-specific response to climate reconstruction in upper-elevation mixed-conifer forests of the western Sierra Nevada, California. Canadian Journal of Forest Research, 37, 1681 – 1691.
  • Hurteau, M., & North, M. (2009). Response of Arnica dealbata to climate change, nitrogen deposition, and fire. Plant Ecology, 202, 191-194.
  • Jovan, S. Lichen bioindication of biodiversity, air quality, and climate: baseline results from monitoring in Washington, Oregon, and California. (2008). General Technical Report PNW-GTR-737. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 115 p.
  • Karl, T. R., Melillo, J. M., & Peterson, T. C. (2009). Global climate change impacts in the United States. New York, NY, USA: Cambridge University Press.
  • Kelly, A. E. & Goulden, M. L. (2008). Rapid shifts in plant distribution with recent climate change. Proceedings of the National Academy of Sciences, 105 (33), 11823-11826.
  • Lloyd, A. H. & Graumlich, L. J. (1997). Holocene dynamics of treeline forests in the Sierra Nevada. Ecology, 78(4), 1199-1210.
  • Lloyd, A. H. (1997). Response of tree-line populations of foxtail pine (Pinus balfouriana) to climate variation over the last 1000 years. Canadian Journal of Forest Research, 27, 936 – 942.
  • Millar, C. I., King, J. C., Westfall, R. D., Alden, H. A. & Delany, D. L. (2006). Late Holocene forest dynamics, volcanism, and climate change at Whitewing Mountain and San Joaquin, Mono County, Sierra Nevada, CA, USA. Quaternary Research, 66, 273 –
  • Millar, C. I., Westfall, R. D., Delany, D. L., King, J. C. & Graumlich, L. J. (2004). Response of subalpine conifers in the Sierra Nevada, California, U. S. A., to 20th-century warming and decadal climate variability. Arctic, Antarctic, and Alpine Research, 36(2), 181 –
  • Salzer, M. W., Hughes, M. K., Bunn, A. G. & Kipfmueller, K. F. (2009). Recent unprecendented tree-ring growth in bristlecone pine at the highest elevations and possible causes. Proceedings of the National Academy of Sciences, 106(48), 20348 – 20353.
  • Taylor, A. H. (1995). Forest expansion and climate change in the mountain hemlock (Tsuga mertensiana) zone, Lassen Volcanic Park, California, U.S.A. Arctic and Alpine Research, 27 (3), 207-216.

Arid Lands
  • Breshears, D. D., Myers, O. B., Meyer, C. W., Barnes, F. J., Zou, C. B…. & Pockman, W. T. (2009). Tree die-off in response to global change type drought: mortality insights from a decade of plant water-potential measurements. Frontiers in Ecology and the Environment, 7, 1 – 5. doi:10.1890/080016
  • Karl, T. R., Melillo, J. M., & Peterson, T. C. (2009). Global climate change impacts in the United States. New York, NY, USA: Cambridge University Press.
  • Lawler, J. J., Tear, T. H., Pyke, C., Shaw, M. R., Gonzalez, P., Kareiva,P., Hansen, L., Hannah, L., Klausmeyer, K., Aldous, A., Bienz, C., & Pearsall, S. (2010). Resource management in a changing and uncertain climate. Frontiers in Ecology and the Environment, 8(1), 35-43.
  • Lawson, D. M., Regan, H. M., Zedlers, P. H., & Franklin, J. (2010). Cumulative effects of land use, altered fire regime and climate change on persistence of Ceanothus verrucosus, a rare, fire-dependent plant species. Global Change Biology, 16, 2518-2529. doi: 10.1111/j.1365-2486.2009.02143.x
  • Van de Ven, C. M., Weiss, S. B. & Ernst, W. G. (2007). Plant species distributions under present conditions and forecasted for warmer climates in an arid mountain range. Earth Interactions, 11 (Paper No. 9), 1 – 33.

Temperate Forests
  • Barbour, E. & Kueppers, L. M. (2011). Conservation and management of ecological systems in a changing California. Climatic Change, DOI 10.1007/s10584-011-0246-y, 1-
  • Conlisk, E., Lawson, D., Syphard, A. D., Franklin, J., Flint L, … Regan, H. M. (2012) The roles of dispersal, fecundity, and Predation in the population persistence of an oak (Quercus engelmannii) under global change. PLoS ONE, 7(5),1 – 11. e36391. doi:10.1371/journal.pone.0036391.
  • Damschen, E. I., Harrison, S., Ackerly, D. D., Fernandez-Going, B. M. & Anacker, B. L. (2012). Endemic plant communities on special soils: early victims or hardy survivors of climate change? Journal of Ecology, doi: 10.1111/j.1365-2745.2012.01986.x
  • Gauthier, M. –M. & Jacobs, D. F. (2011). Walnut (Juglans spp.) ecophysiology in response to environmental stresses and potential acclimation to climate change. Annals of Forest Science, 68(8), 1277-1290. doi: 10.1007/s13595-011-0135-6
  • Jimerson, T. M. & Carothers, S. K. (2002). Northwest California oak woodlands: environment, species composition, and ecological status. In R. B. Standiford, D. McCreary & K. L. Purcell, (technical coordinators ). Proceedings of the fifth symposium on oak woodlands: oaks in California’s changing landscape. 2001 October 22-25; San Diego, CA. General Technical Report PSW-GTR-184. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station; 846 p.
  • Lutz, J. A., van Wagtendonk, J. W., & Franklin, J. F. (2009). Twentieth-century decline of large-diameter trees in Yosemite National Park, California, USA. Forest Ecology and Management, 257, 2296-2307.
  • McLaughlin, B. C. & Zavaleta, E. S. (2012). Predicting species responses to climate change: demography and climate microrefugia in California valley oak (Quercus lobata). Global Change Biology, 18, 2301 – 2312. doi: 10.1111/j.1365-2486.2011.02630.x
  • Rogers, P. C., Shepperd, W. D. & Bartos, D. L. (2007). Aspen in the Sierra Nevada: Regional conservation of a continental species. Natural Areas Journal, 27 (2), 183 –
  • Royce, E. B. & Barbour, M. G. (2001). Mediterranean climate effects. II. Conifer growth phenology across a Sierra Nevada ecotone. American Journal of Botany, 88(5), 919 –
  • Sork, V. L., Davis, F. W., Westfall, R., Flint, A., Ikegami, M., Wang, H., & Grivet, D. (2010). Gene movement and genetic association with regional climate gradients in California valley oak (Quercus lobata Nйe) in the face of climate change. Molecular Ecology, 19, 3806–3823. doi: 10.1111/j.1365-294X.2010.04726.x
  • Spero, J. G. (2002). Development and fire trends in oak woodlands of the northwestern Sierra Nevada foothills. In R. B. Standiford, D. McCreary & K. L. Purcell (technical coordinators): Proceedings of the fifth symposium on oak woodlands: oaks in California’s changing landscape. 2001 October 22-25; San Diego, CA. General Technical Report PSW-GTR-184. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station; 846 p.
  • York, R. A., Fuchs, D., Battles, J. J., & Stephens, S. L. (2010). Radial growth responses to gap creation in large, old Sequoiadendron giganteum. Applied Vegetation Science, 13(4), 498-509.

Additional Terrestrial References

  • Alexander, J. D., N. E. Seavy, and P. E. Hosten. (2007). Using Conservation Plans and Bird Monitoring to Evaluate Ecological Effects of Management: An Example with Fuels Reduction Activities in Southwest Oregon. Forest Ecology and Management 238: 375–383.
  • Aubrey, K.B. and C.M. Raley. 2006. Ecological characteristics of fishers (Martes pennanti) in the Southern Oregon Cascade Range. USDA Forest Service, Pacific Northwest Research Station, Olympia Forestry Sciences Laboratory, Olympia, WA.
  • Aubry, K.B., C.M Raley, S.W. Buskirk, W.J. Zielinski, M.W. Schwartz, R.T. Golightly, K.L. Purcell, R.D. Weir and J.S. Yaeger. Submitted. Meta-analysis of habitat selection at resting sites by fishers in the Pacific Coastal states and provinces. Journal of Wildlife Management.
  • Aubry K.B., Zielinski W.J., Raphael M.G., Proulx G., and Buskirk, S.W., eds. 2012. Biology and Conservation of Martens, Sables and Fishers: A New Synthesis. Cornell Univ. Press, Ithaca, NY. 580pp.
  • Buskirk, A.S. Harestad, M.G. Raphael, and R.A. Powell, editors. 1994. Martens, sables and fishers: biology and conservation. Cornell University Press, Ithaca, NY. 484 pp.
  • California Department of Fish and Game. 2010. A status review of the fisher (Martes pennanti) in California. Report to the Fish and Game Commission. Sacramento, CA. 104 pp. + appendices.
  • Buskirk, S.W., and L.R. Ruggiero. 1994. American marten. Pages 7-37 in American marten, fisher, lynx, and wolverine in the western United States (L.F. Ruggiero, K.B. Aubry, S.W. Buskirk, L.J. Lyon, and W.J. Zielinski, editors). United States Department of Agriculture Forest Service General Technical Report. RM-254.
  • Chase, M. K. & Geupel, G. R. (2005). The Use of Avian Focal Species for Conservation Planning in California. In: Ralph, C. John; Rich, Terrell D., editors 2005. Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference. 2002 March 20-24; Asilomar, California, Volume 1 Gen. Tech. Rep. PSW-GTR-191. Albany, CA: U.S. Dept. of Agriculture, Forest Service, Pacific Southwest Research Station: p. 130-142
  • Ellis, L.M. 1998. Habitat-use patterns of the American marten in the southern Cascade mountains of California, 1992-1994. Master’s thesis. Department of Wildlife, Humboldt State University, Arcata, CA.
  • Gabriel, M.W. 2013. Integral Ecology Research Center. Grow site impacts and new mortalities from anticoagulant rodenticides. Presentation at the Western Section of The Wildlife Society. Sacramento, CA. Jan. 30 – Feb. 1, 2013.
  • Grenfell, W.E. and M. Fasenfest. 1979. Winter food habits of fishers, Martes pennanti, in northwestern California. Calif. Fish and Game 65:186-189.
  • Grinnell, J., J.S. Dixon, and J.M. Linsdale. 1937. Fur-bearing mammals of California. Vol. 1. University of California Press, Berkeley, CA. 375 pp.
  • Hargis, C. D., Bissonette, John. A. and Turner, D. L. 1999. The influence of forest fragmentation and landscape pattern on American martens. Journal of Applied Ecology, 36: 157–172. doi: 10.1046/j.1365-2664.1999.00377.x
  • Kirk, T.A., and W.J. Zielinski. 2009. Developing and testing a landscape habitat suitability model for the American marten (Martes americana) in the Cascades mountains of California. Landscape Ecology 24:759-773.
  • Knaus, B.J., R. Cronn, A. Liston, K. Pilgrim, and M.K. Schwartz. 2011. Mitochondrial genome sequences illuminate maternal lineages of conservation concern in rare carnivore. BMC Ecology 2011 11:10.
  • Lofroth, E. C., C. M. Raley, J. M. Higley, R. L. Truex, J. S. Yaeger, J. C. Lewis, P. J. Happe, L. L. Finley, R. H. Naney, L. J. Hale, A. L. Krause, S. A. Livingston, A. M. Myers, and R. N. Brown. 2010. Conservation of fishers (Martes pennanti) in south-central British Columbia, western Washington, western Oregon, and California–Volume I: Conservation Assessment. USDI Bureau of Land Management, Denver, Colorado, USA. 163pp.
  • Lofroth, E. C., J. M. Higley, R. H. Naney, C. M. Raley, J. S. Yaeger, S. A. Livingston, and R. L. Truex. 2011. Conservation of Fishers (Martes pennanti) in South-Central British Columbia, Western Washington, Western Oregon, and California–Volume II: Key Findings From Fisher Habitat Studies in British Columbia, Montana, Idaho, Oregon, and California. USDI Bureau of Land Management, Denver, Colorado, USA. 117pp.
  • Mazzoni, A. 2002. Habitat use by fishers (Martes pennanti) in the southern Sierra Nevada, California. M.S. Thesis. California State University, Fresno, CA.
  • Naney, R. H., L. L Finley, E. C. Lofroth, P. J. Happe, A. L. Krause, C. M. Raley, R. L. Truex, L. J. Hale, J. M. Higley, A. D. Kosic, J. C. Lewis, S. A. Livingston, D. C. Macfarlane, A. M. Myers, and J. S. Yaeger. 2012. Conservation of fishers (Martes pennanti) in south-central British Columbia, western Washington, western Oregon, and California–Volume III: Threat Assessment. USDI Bureau of Land Management, Denver, Colorado, USA. 55pp.
  • North, M., P. Stine, K. O’Hara, W. Zielinski, and S. Stephens. 2009. An ecosystem management strategy for Sierran mixed conifer forests. General technical report PSW-GTR-220. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 49 pages.
  • Powell RA. 1993. The fisher: life history, ecology and behavior. 2nd ed. Minneapolis: University of Minnesota Press.
  • Spencer, W.D., H.L. Rustigian, R.M. Scheller, A. Syphard, J. Strittholt, and B. Ward. 2008. Baseline evaluation of fisher habitat and population status, and effects of fires and fuels management on fishers in the southern Sierra Nevada. Unpublished report for USDA Forest Service, Pacific Southwest Region. Conservation Biology Institute. Corvallis, OR. 133 pp + appendices.
  • Spencer, W.D., H. Rustigian-Romsos, J. Strittholt, R. Scheller, W. Zielinski, and R. Truex. 2011. Using occupancy and population models to assess habitat conservation opportunities for an isolated carnivore population. Biological Conservation 144: 788-803.
  • Spencer, W. and H. Rustigian-Romsos. 2012. Decision-support maps and recommendations for conserving rare carnivores in the interior mountains of California. Unpublished report for Sierra Forest Legacy. 37pp.
  • Stephens, J. L., K. Kreitinger, C. J. Ralph, and M. T. Green, eds. (2011). Informing Ecosystem Management: Science and Process for Landbird Conservation in the Western United States. Biological Technical Publication FWS/BTP-R1014-2011. Portland, Oregon: U.S. Department of Interior, Fish and Wildlife Service. http://library.fws.gov/BTP/information-ecosystem-management-2011.pdf.
  • Thompson, C., K. Purcell, J. Garner and R. Green. 2009. Kings River Fisher Project. Two-year preliminary progress report presented to the Western Section of The Wildlife Society meeting, January 21-23, 2009. Sacramento, California.
  • Truex, R.L. W.J. Zielinski, J.S. Bolis, and J.M. Tucker. 2009. Fisher population monitoring in the southern Sierra Nevada, 2002 – 2008. Paper presented at the 5th International Martes Symposium, Seattle, WA. September 8–12, 2009.
  • Tucker, J.M., M.K. Schwartz, K.L. Pilgrim, and F.W. Allendorf. 2012. Historical and contemporary DNA indicate fisher decline and isolation occurred prior to the European settlement of California. PLoS ONE 7(12): e52803. doi: 10.1371/journal.pone.0052803
  • USDA Forest Service. 2006. Sierra Nevada forest plan accomplishment monitoring report for 2005. USDA Forest Service, Pacific Southwest Region R5-MR-000. 12pp.
  • Weir, R.D. 2003. Status of the fisher in British Columbia. British Columbia Ministry of Sustainable Resource Management, Conservation Data Center, and the Ministry of Water, Land, and Air Protection, Biodiversity Branch. Victoria, British Columbia, Canada.
  • Wiens, J. A., Hayward, G. D., Hoilthause, R. S., Wisdom, M. J. (2008). Using Surrogate Species and Groups for Conservation Planning and Management. Bioscience, 58(3), 241-252.
  • Zielinski, W.J. 2013. The forest carnivores: fisher and marten. Pages xxx-xxx in: Long, Jonathan; Skinner, Carl; North, Malcolm; Winter, Pat; Zielinski, Bill; Hunsaker, Carolyn; Collins, Brandon; Keane, John; Lake, Frank; Wright, Jessica; Moghaddas, Emily; Jardine, Angela; Hubbert, Ken; Pope, Karen; Bytnerowicz, Andrzej; Fenn, Mark; Busse, Matt; Charnley, Susan; Patterson, Trista; Quinn-Davidson, Lenya; Safford, Hugh; chapter authors and Synthesis team members. Bottoms, Rick; Hayes, Jane; team coordination and review. Meyer, Marc; Herbst, David; Matthews, Kathleen; additional contributors. USDA Forest Service Pacific Southwest Research Station. 2013. Science Synthesis to support Forest Plan Revision in the Sierra Nevada and Southern Cascades. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 504 p.
  • Zielinski, W.J, R.L. Truex, J.R. Dunk and T. Gaman. 2006. Using forest inventory data to assess fisher resting habitat suitability in California. Ecological Applications 16:1010-1025.
  • Zielinski, W.J., R.L. Truex, C.V. Ogan, and K.Busse.1997. Detection surveys for fishers and American martens in California, 1989-1994: Summary and interpretations. Pages 372-392. In G. Proulx, H.N. Bryant, and P.M. Woodard, editors. Martes: taxonomy, ecology, techniques and management. Provincial Museum of Alberta, Alberta, Canada.
  • Zielinski, W.J., R.L. Truex, R. Schlexer, L.A. Campbell, and C. Carroll. 2005. Historical and contemporary distributions of carnivores in forests of the Sierra Nevada, California. J. Biogeog. 32:1385-1407.
  • Zielinski, W.J, R.L. Truex, F.V. Schlexer, L.A. Campbell, and C. Carroll. 2005. Historical and contemporary distributions of carnivores in forests of the Sierra Nevada, California, U.S.A. Journal of Biogeography 32:1385-1407.
  • Zielinski, W.J., R.L. Truex, G.A. Schmidt, F.V. Schlexer, K.N. Schmidt, and R.H. Barrett. 2004a. Resting habitat selection by fishers in California. J. Wildl. Mngt. 68(3):475-492.
  • Zielinski, W.J., R.L. Truex, G.A. Schmidt, F.V. Schlexer, K.N. Schmidt, and R.H. Barrett. 2004b. Home range characteristics of fishers in California. J. Mammalogy, 85(4):649–657.
  • Zielinski, W.J., J.A. Baldwin, R.L. Truex, J.M. Tucker, and P.A. Flebbe. 2013. Estimating trend in occupancy for the southern Sierra fisher Martes pennanti population. Journal of Fish and Wildlife Management 4(1):xx-xx; e1944-687x. doi: 10:3996/012012-JFWM-002. 17p.


Additional references to consider on terrestrial ecosystems (animal communities)/climate change (reviewed in TACCIMO:**http://goo.gl/Lg3Bn)**):

  • A’Bear, A. D., Boddy, L. & Jones, T. H. (2012). Impacts of elevated temperature on the growth and functioning of decomposer fungi are influenced by grazing collembola. Global Change Biology, 18, 1823 – 1832.
  • Aber, J. D., Goodale, C. L., Ollinger, S. V., Smith, M., Magill, A. H., Martin, M. E.,…Stoddard, J. L. (2001). Forest processes and global environmental change: Predicting the effects of individual and multiple stressors. BioScience, 51(9), 735-751.
  • Alpert, H. & Loik, M. E. (2013). Pinus jeffreyi establishment along a forest-shrub ecotone in eastern California, USA. Journal of Arid Environments, 90, 12 – 21.
  • Barbour, E. & Kueppers, L. M. (2011). Conservation and management of ecological systems in a changing California. Climatic Change, DOI 10.1007/s10584-011-0246-y, 1-
  • Blois, J. L., McGuire, J. L. & Hadly, E. A. (2010). Small mammal diversity loss in response to late-Pleistocene climatic change. Nature, 465, 771 – 775.
  • Bruzgul, J. & Root, T. L. (2010) Temperature and long-term breeding trends in California birds: Utilizing and undervalued historical database. California Energy Commission, PIER Energy-Related Environmental Research Program, CEC-500-2010-002.
  • Breshears, D. D., Myers, O. B., Meyer, C. W., Barnes, F. J., Zou, C. B…. & Pockman, W. T. (2009). Tree die-off in response to global change type drought: mortality insights from a decade of plant water-potential measurements. Frontiers in Ecology and the Environment, 7, 1 – 5. doi:10.1890/080016
  • Bunn, A. G., Waggoner, L. A. & Graumlich, L. J. (2005). Topographic mediation of growth in high elevation foxtail pine (Pinus balfouriana Grev. et Balf.) forests in the Sierra Nevada, USA. Global Ecology and Biogeography, 14, 103 – 114.
  • Conlisk, E., Lawson, D., Syphard, A. D., Franklin, J., Flint L, … Regan, H. M. (2012) The roles of dispersal, fecundity, and Predation in the population persistence of an oak (Quercus engelmannii) under global change. PLoS ONE, 7(5),1 – 11. e36391. doi:10.1371/journal.pone.0036391.
  • Dahlhoff, E. P., Fearnley, S. L., Bruce, D. A., Gibbs, A. G., Stoneking, R., … & Rank, N. E. (2008). Effects of temperature on physiology and reproductive success of a montane leaf beetle: Implications for persistence of native populations enduring climate change. Physiological and Biochemical Zoology, 81(6), 718 – 732.
  • Damschen, E. I., Harrison, S., Ackerly, D. D., Fernandez-Going, B. M. & Anacker, B. L. (2012). Endemic plant communities on special soils: early victims or hardy survivors of climate change? Journal of Ecology, doi: 10.1111/j.1365-2745.2012.01986.x
  • Diaz, H. F. & Eischeid, J. K. (2007). Disappearing "alpine tundra" Koppen climatic type in the western United States. Geophysical Research Letters, 34 (L18707), 1-4.
  • Eastman, L. M., Morelli, T. L., Rowe, K.C., Conroy, C. J. & Moritz, C. (2012). Size increase in high elevation ground squirrels over the last century. Global Change Biology, 18, 1499 – 1508.
  • Eckert, A. J. & Eckert, M. L. (2007). Environmental and ecological effects on size class distributions of foxtail pine (Pinus balfouriana, Pinaceae) in the Klamath Mountains, California. Madrono, 54(2), 117 – 125.
  • Forister, M. L., McCall, A. C., Sanders, N. J., Fordyce, J. A., Thorne, J. H., O'Brien, J., Waetjen, D. P., & Shapiro, A.M. (2010). Compounded effects of climate change and habitat alteration shift patterns of butterfly diversity. Proceedings of the National Academy of Science, 107 (5), 2088-2092.
  • Gardali, T., Howell, C. A., Seavy, N. E. Shuford, W. D. & Stralberg, D. (2011). Projected effects of climate change in California: Ecoregional summaries emphasizing consequences for wildlife, Version 1.0. Petaluma, CA: PRBO Conservation Science. 68pp. http://data.prbo.org/apps/bssc/climatechange
  • Gauthier, M. –M. & Jacobs, D. F. (2011). Walnut (Juglans spp.) ecophysiology in response to environmental stresses and potential acclimation to climate change. Annals of Forest Science, 68(8), 1277-1290. doi: 10.1007/s13595-011-0135-6
  • Goodman, R. E., Lebuhn, G., Seavy, N.E., Gardali, T., & Bluso-Demers, J. D.(2012). Avian body size changes and climate change: warming or increasing variability? Global Change Biology, 18, 63-73.
  • Graham, E. A., Rundel, P. W., Kaiser, W., Lam, Y., Stealey, M. & Yuen, E.M. (2012). Fine-scale patterns of soil and plant surface temperatures in an alpine fellfield habitat, White Mountains, California. Arctic, Antarctic, and Alpine Research, 44(3), 288 – 295.
  • Hurteau, M., Zald, H. & North, M. (2007). Species-specific response to climate reconstruction in upper-elevation mixed-conifer forests of the western Sierra Nevada, California. Canadian Journal of Forest Research, 37, 1681 – 1691.
  • Hurteau, M., & North, M. (2009). Response of Arnica dealbata to climate change, nitrogen deposition, and fire. Plant Ecology, 202, 191-194.
  • Jimerson, T. M. & Carothers, S. K. (2002). Northwest California oak woodlands: environment, species composition, and ecological status. In R. B. Standiford, D. McCreary & K. L. Purcell, (technical coordinators ). Proceedings of the fifth symposium on oak woodlands: oaks in California’s changing landscape. 2001 October 22-25; San Diego, CA. General Technical Report PSW-GTR-184. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station; 846 p.
  • Jovan, S. Lichen bioindication of biodiversity, air quality, and climate: baseline results from monitoring in Washington, Oregon, and California. (2008). General Technical Report PNW-GTR-737. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 115 p.
  • Karl, T. R., Melillo, J. M., & Peterson, T. C. (2009). Global climate change impacts in the United States. New York, NY, USA: Cambridge University Press.
  • Kelly, A. E. & Goulden, M. L. (2008). Rapid shifts in plant distribution with recent climate change. Proceedings of the National Academy of Sciences, 105 (33), 11823-11826.
  • Klausmeyer, K. R., Shaw, M. R., MacKenzie, J. B. & Cameron, D. R. (2011). Landscape-scale indicators of biodiversity’s vulnerability to climate change. Ecosphere, 2(8), 1 - 18. doi:10.1890/ES11-00044.1
  • Kueppers, L. M., Snyder, M. A., Sloan, L. C., Zavaleta, E. S., & Fulfrost,B. (2005). Modeled regional climate change and California oak ranges. Proceedings of the National Academy of Sciences, 102(45), 16281-16286.
  • Lawler, J. J., Tear, T. H., Pyke, C., Shaw, M. R., Gonzalez, P., Kareiva,P., Hansen, L., Hannah, L., Klausmeyer, K., Aldous, A., Bienz, C., & Pearsall, S. (2010). Resource management in a changing and uncertain climate. Frontiers in Ecology and the Environment, 8(1), 35-43.
  • Lawson, D. M., Regan, H. M., Zedlers, P. H., & Franklin, J. (2010). Cumulative effects of land use, altered fire regime and climate change on persistence of Ceanothus verrucosus, a rare, fire-dependent plant species. Global Change Biology, 16, 2518-2529. doi: 10.1111/j.1365-2486.2009.02143.x
  • Lenihan, J. M., Drapek, R., Bachelet, D., & Neilson, R. P. (2003). Climate change effects on vegetation distribution, carbon, and fire in California. Ecological Applications, 13(6), 1667-1681.
  • Lenihan, J. M., Bachelet, D., Drapek, R., & Neilson, R. P. (2006). The response of vegetation distribution, ecosystem productivity, and fire in California to future climate scenarios simulated by the MC1 dynamic vegetation model. California Energy Commission, PIER Energy-Related Environmental Research Program, CEC-500-2005-191-SF, 25pp.
  • Lloret, F., Penuelas, J., Prieto, P., Llorens, L., & Estiarte, M. (2009). Plant community changes induced by experimental climate change: Seedling and adult species composition. Perspectives in Plant Ecology, Evolution and Systematics, 11, 53-63.
  • Loarie, S. R., Carter, B. E., Hayhoe, K., McMahon, S., Moe, R., Knight, C. A., & Ackerly, D. D. (2008). Climate Change and the Future of California's Endemic Flora. PLoS ONE 3(6), e2502. doi:10.1371/journal.pone.0002502
  • Lutz, J. A., Van Wagtendonk, J. W., & Franklin, J. F. (2010). Climatic water deficit, tree species ranges, and climate change in Yosemite National Park. Journal of Biogeography, 37(5), 936-950.
  • Lloyd, A. H. (1997). Response of tree-line populations of foxtail pine (Pinus balfouriana) to climate variation over the last 1000 years. Canadian Journal of Forest Research, 27, 936 – 942
  • Lloyd, A. H. & Graumlich, L. J. (1997). Holocene dynamics of treeline forests in the Sierra Nevada. Ecology, 78(4), 1199-1210.
  • Lutz, J. A., van Wagtendonk, J. W., & Franklin, J. F. (2009). Twentieth-century decline of large-diameter trees in Yosemite National Park, California, USA. Forest Ecology and Management, 257, 2296-2307.
  • McLaughlin, B. C. & Zavaleta, E. S. (2012). Predicting species responses to climate change: demography and climate microrefugia in California valley oak (Quercus lobata). Global Change Biology, 18, 2301 – 2312. doi: 10.1111/j.1365-2486.2011.02630.x
  • Macmynowski, D. P., Root, T. L., Ballard, G. & Geupel, G. R. (2007). Changes in spring arrival of Nearctic-Neotropical migrants attributed to multiscalar climate. Global Change Biology, 13, 2239 – 2251. doi: 10.1111/j.1365-2486.2007.01448.x
  • Millar, C. I., King, J. C., Westfall, R. D., Alden, H. A. & Delany, D. L. (2006). Late Holocene forest dynamics, volcanism, and climate change at Whitewing Mountain and San Joaquin, Mono County, Sierra Nevada, CA, USA. Quaternary Research, 66, 273 –
  • Millar, C. I., Westfall, R. D., Delany, D. L., King, J. C. & Graumlich, L. J. (2004). Response of subalpine conifers in the Sierra Nevada, California, U. S. A., to 20th-century warming and decadal climate variability. Arctic, Antarctic, and Alpine Research, 36(2), 181 –
  • Monzon, J., Moyer-Homer, L., & Palamar, M. B. (2011). Climate change and species range dynamics in protected areas. BioScience, 61(10), 752-761.
  • Moritz, C., Patton, J. L., Conroy, C. J., Parra, J. L., White, G. C., & Beissinger, S. R. (2008). Impact of a century of climate change on small-mammal communities in Yosemite National Park, USA. Science, 322, 261-264.
  • Moser, S., Franco, G., Pittiglio, W., Chou, W., & Cayan, D. (2009) The future is now: An update on climate change science impacts and response options for California. California Energy Commission Public Interest Energy Research Program, CEC-500-
  • Parra, J. L. & Monahan, W. B. (2008). Variability in 20th century climate change reconstructions and its consequences for predicting geographic responses of California mammals. Global Change Biology, 14, 1-17.
  • Preston, K. L., Rotenberry, J. T., Redak, R.A., & Allen, M. F. (2008). Habitat shifts of endangered species under altered climate conditions: importance of biotic interactions. Global Change Biology, 14, 2501-2525.
  • Rehfeldt, G. E., Crookston, N. L., Saenz-Romero, C. & Campbell, E. M. (2012).North American vegetation model for land-use planning in a changing climate: a solution to large classification problems. Ecological Applications, 22 (1), 119 – 141.
  • Rice, K. J. & Emery, N. C. (2003). Managing microevolution: restoration in the face of global change. Frontiers in Ecology and the Environment, 1 (9), 469 – 478.
  • Rogers, P. C., Shepperd, W. D. & Bartos, D. L. (2007). Aspen in the Sierra Nevada: Regional conservation of a continental species. Natural Areas Journal, 27 (2), 183 –
  • Royce, E. B. & Barbour, M. G. (2001). Mediterranean climate effects. II. Conifer growth phenology across a Sierra Nevada ecotone. American Journal of Botany, 88(5), 919 –
  • Rubidge, E. M., Monahan, W. B., Parra, J. L., Cameron, S. E., & Brashares, J. S. (2011). The role of climate, habitat, and species co-occurrence as drivers of change in small mammal distributions over the past century. Global Change Biology, 17, 696-708. doi: 10.1111/j.1365-2486.2010.02297.x
  • Rubidge, E. M., Patton, J. L., Lim, M., Burton, A. C., Brashares, J. S. & Moritz, C. (2012).Climate-induced range contraction drives genetic erosion in an alpine mammal. Nature, 2, 285 – 288.
  • Salzer, M. W., Hughes, M. K., Bunn, A. G. & Kipfmueller, K. F. (2009). Recent unprecendented tree-ring growth in bristlecone pine at the highest elevations and possible causes. Proceedings of the National Academy of Sciences, 106(48), 20348 – 20353.
  • Sork, V. L., Davis, F. W., Westfall, R., Flint, A., Ikegami, M., Wang, H., & Grivet, D. (2010). Gene movement and genetic association with regional climate gradients in California valley oak (Quercus lobata Nйe) in the face of climate change. Molecular Ecology, 19, 3806–3823. doi: 10.1111/j.1365-294X.2010.04726.x
  • Spero, J. G. (2002). Development and fire trends in oak woodlands of the northwestern Sierra Nevada foothills. In R. B. Standiford, D. McCreary & K. L. Purcell (technical coordinators): Proceedings of the fifth symposium on oak woodlands: oaks in California’s changing landscape. 2001 October 22-25; San Diego, CA. General Technical Report PSW-GTR-184. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station; 846 p.
  • Stralberg, D., Jongsomjit, D., Howell, C. A., Snyder, M. A., Alexander, J. D.,.... & Root, T. L. (2009). Re-shuffling of species with climate disruption: A no-analog future for California birds? PLoS ONE, 4 (9), 1 - 8. doi:10.1371/journal.pone.0006825
  • Taylor, A. H. (1995). Forest expansion and climate change in the mountain hemlock (Tsuga mertensiana) zone, Lassen Volcanic Park, California, U.S.A. Arctic and Alpine Research, 27 (3), 207-216.
  • Tingley, M. W., Monahan, W. B., Beissinger, S. R. & Moritz, C. (2009). Birds track their Grinnellian niche through a century of climate change. Proceedings of the National Academy of Sciences, 106 (2), 19637 – 19643.
  • Tingley, M. W., Koo, M. S., Moritz, C., Rush, A. C. & Beissinger, S. R. (2012). The push and pull of climate change causes heterogeneous shifts in avian elevational ranges. Global Change Biology, doi: 10.1111/j.1365-2486.2012.02784.x
  • Van de Ven, C. M., Weiss, S. B. & Ernst, W. G. (2007). Plant species distributions under present conditions and forecasted for warmer climates in an arid mountain range. Earth Interactions, 11 (Paper No. 9), 1 – 33.
  • Yang, D. -S., Conroy, C. J., & Moritz, C. (2011). Contrasting responses of Peromyscus mice of Yosemite National Park to recent climate change. Global Change Biology, 17,
  • York, R. A., Fuchs, D., Battles, J. J., & Stephens, S. L. (2010). Radial growth responses to gap creation in large, old Sequoiadendron giganteum. Applied Vegetation Science, 13(4), 498-509.


Additional references to consider on terrestrial ecosystems (animal communities)/climate change (reviewed in TACCIMO:http://goo.gl/Lg3Bn)):

Animal Communities - general
  • Barbour, E. & Kueppers, L. M. (2011). Conservation and management of ecological systems in a changing California. Climatic Change, DOI 10.1007/s10584-011-0246-y, 1-
  • Gardali, T., Howell, C. A., Seavy, N. E. Shuford, W. D. & Stralberg, D. (2011). Projected effects of climate change in California: Ecoregional summaries emphasizing consequences for wildlife, Version 1.0. Petaluma, CA: PRBO Conservation Science. 68pp. http://data.prbo.org/apps/bssc/climatechange
  • Preston, K. L., Rotenberry, J. T., Redak, R.A., & Allen, M. F. (2008). Habitat shifts of endangered species under altered climate conditions: importance of biotic interactions. Global Change Biology, 14, 2501-2525

Birds
  • Bruzgul, J. & Root, T. L. (2010) Temperature and long-term breeding trends in California birds: Utilizing and undervalued historical database. California Energy Commission, PIER Energy-Related Environmental Research Program, CEC-500-2010-002.
  • Goodman, R. E., Lebuhn, G., Seavy, N.E., Gardali, T., & Bluso-Demers, J. D.(2012). Avian body size changes and climate change: warming or increasing variability? Global Change Biology, 18, 63-73.
  • Macmynowski, D. P., Root, T. L., Ballard, G. & Geupel, G. R. (2007). Changes in spring arrival of Nearctic-Neotropical migrants attributed to multiscalar climate. Global Change Biology, 13, 2239 – 2251. doi: 10.1111/j.1365-2486.2007.01448.x
  • Monzon, J., Moyer-Homer, L., & Palamar, M. B. (2011). Climate change and species range dynamics in protected areas. BioScience, 61(10), 752-761.
  • Preston, K. L., Rotenberry, J. T., Redak, R.A., & Allen, M. F. (2008). Habitat shifts of endangered species under altered climate conditions: importance of biotic interactions. Global Change Biology, 14, 2501-2525.
  • Stralberg, D., Jongsomjit, D., Howell, C. A., Snyder, M. A., Alexander, J. D.,.... & Root, T. L. (2009). Re-shuffling of species with climate disruption: A no-analog future for California birds? PLoS ONE, 4 (9), 1 - 8. doi:10.1371/journal.pone.0006825
  • Tingley, M. W., Monahan, W. B., Beissinger, S. R. & Moritz, C. (2009). Birds track their Grinnellian niche through a century of climate change. Proceedings of the National Academy of Sciences, 106 (2), 19637 – 19643.
  • Tingley, M. W., Koo, M. S., Moritz, C., Rush, A. C. & Beissinger, S. R. (2012). The push and pull of climate change causes heterogeneous shifts in avian elevational ranges. Global Change Biology, doi: 10.1111/j.1365-2486.2012.02784.x

Invertebrates
  • A’Bear, A. D., Boddy, L. & Jones, T. H. (2012). Impacts of elevated temperature on the growth and functioning of decomposer fungi are influenced by grazing collembola. Global Change Biology, 18, 1823 – 1832.
  • Dahlhoff, E. P., Fearnley, S. L., Bruce, D. A., Gibbs, A. G., Stoneking, R., … & Rank, N. E. (2008). Effects of temperature on physiology and reproductive success of a montane leaf beetle: Implications for persistence of native populations enduring climate change. Physiological and Biochemical Zoology, 81(6), 718 – 732.
  • Forister, M. L., McCall, A. C., Sanders, N. J., Fordyce, J. A., Thorne, J. H., O'Brien, J., Waetjen, D. P., & Shapiro, A.M. (2010). Compounded effects of climate change and habitat alteration shift patterns of butterfly diversity. Proceedings of the National Academy of Science, 107 (5), 2088-2092.

Mammals
  • Blois, J. L., McGuire, J. L. & Hadly, E. A. (2010). Small mammal diversity loss in response to late-Pleistocene climatic change. Nature, 465, 771 – 775.
  • Eastman, L. M., Morelli, T. L., Rowe, K.C., Conroy, C. J. & Moritz, C. (2012). Size increase in high elevation ground squirrels over the last century. Global Change Biology, 18, 1499 – 1508.
  • Moritz, C., Patton, J. L., Conroy, C. J., Parra, J. L., White, G. C., & Beissinger, S. R. (2008). Impact of a century of climate change on small-mammal communities in Yosemite National Park, USA. Science, 322, 261-264.
  • Parra, J. L. & Monahan, W. B. (2008). Variability in 20th century climate change reconstructions and its consequences for predicting geographic responses of California mammals. Global Change Biology, 14, 1-17.
  • Rubidge, E. M., Monahan, W. B., Parra, J. L., Cameron, S. E., & Brashares, J. S. (2011). The role of climate, habitat, and species co-occurrence as drivers of change in small mammal distributions over the past century. Global Change Biology, 17, 696-708. doi: 10.1111/j.1365-2486.2010.02297.x
  • Rubidge, E. M., Patton, J. L., Lim, M., Burton, A. C., Brashares, J. S. & Moritz, C. (2012).Climate-induced range contraction drives genetic erosion in an alpine mammal. Nature, 2, 285 – 288.
  • Yang, D. -S., Conroy, C. J., & Moritz, C. (2011). Contrasting responses of Peromyscus mice of Yosemite National Park to recent climate change. Global Change Biology, 17,

Additional Fisher References
  • Aubry, K.B., S.M. Wisely, C.M. Raley, and S.W. Buskirk. 2004. Zoogeography, spacing patterns, and dispersal in fishers: insights gained from combining field and genetic data. p. 201-220 In D. J. Harrison and A. K. Fuller, eds. Proceedings of the 3rd International Martes Symposium: Martens and fishers (Martes) in human-altered environments: an international perspective. Springer, US. 279p.
  • Aubry K.B., Zielinski W.J., Raphael M.G., Proulx G., and Buskirk, S.W., eds. 2012. Biology and Conservation of Martens, Sables and Fishers: A New Synthesis. Cornell Univ. Press, Ithaca, NY. 580pp.
  • Aubrey, K.B. and C.M. Raley. 2006. Ecological characteristics of fishers (Martes pennanti) in the Southern Oregon Cascade Range. USDA Forest Service, Pacific Northwest Research Station, Olympia Forestry Sciences Laboratory, Olympia, WA.
  • Aubry K.B., Zielinski W.J., Raphael M.G., Proulx G., and Buskirk, S.W., eds. 2012. Biology and Conservation of Martens, Sables and Fishers: A New Synthesis. Cornell Univ. Press, Ithaca, NY. 580pp.
  • Buskirk, A.S. Harestad, M.G. Raphael, and R.A. Powell, editors. 1994. Martens, sables and fishers: biology and conservation. Cornell University Press, Ithaca, NY. 484 pp.
  • California Department of Fish and Game. 2010. A status review of the fisher (Martes pennanti) in California. Report to the Fish and Game Commission. Sacramento, CA. 104 pp. + appendices.
  • Grenfell, W.E. and M. Fasenfest. 1979. Winter food habits of fishers, Martes pennanti, in northwestern California. Calif. Fish and Game 65:186-189.
  • Lofroth, E. C., C. M. Raley, J. M. Higley, R. L. Truex, J. S. Yaeger, J. C. Lewis, P. J. Happe, L. L. Finley, R. H. Naney, L. J. Hale, A. L. Krause, S. A. Livingston, A. M. Myers, and R. N. Brown. 2010. Conservation of fishers (Martes pennanti) in south-central British Columbia, western Washington, western Oregon, and California–Volume I: Conservation Assessment. USDI Bureau of Land Management, Denver, Colorado, USA. 163pp.
  • Lofroth, E. C., J. M. Higley, R. H. Naney, C. M. Raley, J. S. Yaeger, S. A. Livingston, and R. L. Truex. 2011. Conservation of Fishers (Martes pennanti) in South-Central British Columbia, Western Washington, Western Oregon, and California–Volume II: Key Findings From Fisher Habitat Studies in British Columbia, Montana, Idaho, Oregon, and California. USDI Bureau of Land Management, Denver, Colorado, USA. 117pp.
  • Mazzoni, A. 2002. Habitat use by fishers (Martes pennanti) in the southern Sierra Nevada, California. M.S. Thesis. California State University, Fresno, CA.
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[snapshot: 4/9/2013 @0936]




Bond et al. 2009, in a radiotelemetry study, found that California spotted owls preferentially selected high-severity fire areas (which had not been salvage logged) for foraging. In addition, Lee et al. 2012 found that mixed-severity wildland fire, averaging 32% high-severity fire effects, did not decrease California spotted owl territory occupancy, but post-fire salvage logging appeared to adversely affect occupancy.