Concurrent Session I. Conifer Forest Habitats

Some geologic–biologic relationships in southwestern California
Douglas M. Morton
U.S. Geological Survey, Department of Earth Sciences, University of California, Riverside, CA 92521, scamp@ucrac1.ucr.edu

Geologic materials and features can play an important role in governing the distribution of plants that in turn can govern the distribution of animals. In some plant communities, the relationship is a product of the chemistry of the parent rock; or physical property, such as permeability, or rock-surface conditions.
In the montane and chaparral-coastal sage communities of southwestern California some relationships between geology and biology are well known such as the endangered plant species endemic to carbonate rocks in the San Bernardino Mountains. However, many geologic-biologic relationships are less obvious. Black sage (Salvia mellifera) favors gabbro that contains relatively large amounts of calcium, iron and magnesium. Ground-water barriers formed by joints and faults are less obvious than in the desert, but such barriers are important in controlling the distribution of riparian plants. Physiography produced by geologic processes can play an important ecologic role. Closed depressions, extant for 9 million years on the surface of basalt flows, form the vernal pools on Santa Rosa Plateau. Some vegetation changes affect geologic processes or the rate of processes. As an example, some sedimentary rock units are particularly susceptible to surficial landsliding. Introduced grasses with shallow root systems revegetate the denuded landslide areas more rapidly than native species with deeper root systems. The slopes covered by shallow-rooted grasses are more likely to produce soil slips than slopes with deeper rooted natives; thus, the process of landsliding is accelerated with the conversion from coastal sage communities to introduced grasses

Carbonate and pebble plain endemic plants: current knowledge and management challenges
Scott Eliason
Mountaintop District Botanist, San Bernardino National Forest, seliason/r5_sanbernardino@fs.fed.us

Rare plants in the San Bernardino Mountains tend to be associated with one of several narrowly distributed habitat types. The carbonate and pebble plain habitats are among these types, and each support unique complexes of species. High species endemism within these types is likely a result of characteristic environmental conditions, combined with isolation on a range of scales. The rarity of several plant species that occur within these habitat types, combined with considerable ongoing human impacts to these habitats, have led to listing of these species under the federal Endangered Species Act. Considerable distributional and ecological data have been collected on these species, and the listings have accelerated this data gathering process. The listings have also raised the stakes on planning and management efforts directed at protecting and recovering the species. Activities within pebble plain habitat that most challenge management and species protection include gold prospecting, unauthorized vehicle use, and land development in Big Bear Valley and Baldwin Basin. The carbonate habitats have been, and continue to be the subject of considerable study. All of the challenges of managing pebble plain habitat also face carbonate habitat, but large scale mining of limestone within carbonate habitat poses a substantial additional set of challenges. This paper will review the current state of knowledge of carbonate and pebble plain habitats, and the special status plants they support, with examples of how this knowledge is applied to current management challenges.

Sensitive species of snakes, frogs, and salamanders: status and management
Glenn R. Stewart 1, Mark R. Jennings2 and Robert H. Goodman1
1 California State Polytechnic University, Pomona, grstewart@csupomona.edu
2 Department of Herpetology, California Academy of Sciences

Among the snakes, frogs and salamanders that we believe need attention as sensitive species in conifer forest habitats of southern California are: Southern Rubber Boa (Charina bottae umbratica), San Diego Mountain Kingsnake (Lampropeltis zonata pulchra), San Bernardino Mountain Kingsnake (L. z. parvirubra), Mountain Yellow-legged Frog (Rana muscosa), San Gabriel Mountains Slender Salamander (Batrachoseps gabrieli), Large-blotched Salamander (Ensatina eschscholtzii klauberi), and Yellow-blotched Salamander (E. e. croceater). The Southern Rubber Boa currently is state-listed as THREATENED. The Mountain Yellow-legged Frog, two mountain kingsnakes, and two ensatinas currently are recognized by the state as SPECIES OF SPECIAL CONCERN. The slender salamander was just recently described and is not currently listed.
At the present time, the Mountain Yellow-legged Frog is in extreme jeopardy, it is represented by only nine known populations and is being reviewed for federal ENDANGERED status. The status of the other species is not well documented. However, recent studies on the Southern Rubber Boa have verified its taxonomic distinctness, better defined its range, and increased knowledge of its biology. Field work on the San Gabriel Mountains Slender Salamander has increased its known range.
To varying degrees, most of theses species face threats of habitat fragmentation or degradation, and a multitude of other impacts ranging from predation by alien species and human collectors to genetic deterioration and random environmental catastrophes. Further research is needed to elucidate the status and needs of these species, and to provide the basis for appropriate management programs. Programs must be monitored to ensure that objectives are achieved.

The spotted owl in southern California: ecology and special concerns for the maintenance of a forest dwelling species in a human dominated, desert landscape
William S. La Haye 1 and R. J. Gutierrez 2
1 P. O. Box 523, Big Bear City, CA 92314, blahaye@gte.net
2 Wildlife Department, Humboldt State University, Arcata, CA 95521

The spotted owl is a northern forest owl that is a rare inhabitant in southern California. It occurs in a very localized fashion in forested habitats in most of the major mountain ranges in the region. This owl has been studied for more than a decade in the San Bernardino Mountains, and there is strong empirical and demographic evidence that this owl has declined during the study period.
Numerous problems contribute to the difficulties associated with long term maintenance of this species in the region. A list of the key issues affecting this species include: its naturally fragmented distribution, increasing fragmentation caused by urban expansion, wildfires, increased human recreation impacts, and changes in riparian vegetation due to water extraction. Our insight into the plight of the spotted owl is clouded by the fact that we are not sure what is causing the observed decline. And, it is possible that the decline is being caused by a complex interaction of many factors. We provide an update on our current knowledge about the owl and discuss the list of problems that may be impacting this species

Fire control, stand-densification, and stand-replacement fires in southern California conifer forests
Richard A. Minnich
Department of Earth Sciences, University of California Riverside, CA 92521, richard.minnich@ucr.edu

Spatial variation in fire regimes related to climate, productivity, and fuel accumulation rates exert profound selection in the distribution, structure, and dynamics of conifer forests in California. Historical reference data of presuppression forests in southern California and data for modern forests in northern Baja California where fire control is nonexistent or ineffective can be used to determine whether fire control has altered fire regimes and conifer forests. Stand densification and high intensity conflagrations have occurred in many California forest ecosystems over the past century. A critical question is whether recent changes in forests reside within the natural variability of disturbances and successions, or reflect long-term directional vegetation change. A goal in management should be to simulate the dynamics of ecosystems (ecosystem management) as a low maintenance, inexpensive option. In altered ecosystems, restoration goals should be to reverse the impacts of fire control. Management strategies, depending upon ecosystem, may require the use of stand-replacing fires (closed-cone conifer forest), intense subcanopy burns (bigcone Douglas fir, mixed conifer forest), or no management (pinyon-juniper woodlands, subalpine forest).

Fire and field management as restoration tools
Sue Husari
USDA Forest Service, Vallejo CA 94592, shusari/r5@fs.fed.us

Abstract not received.

Air pollution impacts in the mixed conifer forests of southern California
Patrick J. Temple, Andrzej Bytnerowicz, Mark E. Fenn, and Mark A. Poth

USDA Forest Service, Pacific Southwest Research Station, Riverside, CA 92507, temple_patrick/psw_rfl@fs.fed.us
For the past 40+ years, mixed conifer forests in the mountains of southern California have experienced the highest levels of oxidant air pollution and some of the highest levels of nitrogen deposition of any ecosystem in North America. Foliar injury, premature needle abscission, crown thinning, and reduced growth and vigor have been well documented, particularly for ponderosa (Pinus ponderosa Laws.) and Jeffrey (P. jeffrey Grev. and Balf.) pines on the western side of the pollution deposition gradient. Tree mortality of the more ozone-sensitive ponderosa and Jeffrey pines has led to alterations in stand composition, in favor of increased dominance by more ozone-resistant species such as incense cedar (Calocedrus decurrens (Torr.) Florin), white fir (Abies concolor (Gord. & Glend.) Lindl.), and sugar pine (P. lambertiana Doug.). Increased rates of litter deposition, alterations in C/N ratios in litter and soil, and reductions in fine root biomass of trees have also altered the dynamics of biogeochemical processing in stands impacted by ozone and excess N deposition. Research into the effects of atmospheric deposition across the mixed conifer forests of the San Bernardino Mountains continues to provide insights into the complex interactions among anthropogenic and natural stresses in a forest ecosystem.

Concurrent Session II. Coastal Sage Scrub and Chaparral Habitats

History of fire-induced type conversion in California shrublands
Jon E. Keeley
U.S. Geological Survey, Sequoia National Park, Three Rivers, CA 93271, jon_keeley@usgs.gov

Chaparral and coastal sage scrub vegetation have a disproportionately high number of rare and endangered plants and thus threats to these ecosystems are of particular conservation concern. Unnaturally high fire frequency has been a leading cause of degradation of chaparral and coastal sage scrub ecosystems. While these shrublands are fire-adapted, below a certain threshold of fire frequency, resilience is inversely related to the fire return interval – this threshold is approximately 15 years in chaparral and 5-10 years in coastal sage scrub. Numerous studies have shown that unnaturally high fire frequency depletes the native flora and increases the proportion of non-native herbaceous species. Resilience to different fire regimes varies across growth forms and thus it is of particular significance that the growth form distribution of rare species is significantly different from the proportions of growth forms in these communities. Annuals, many of which are highly specialized to postfire environments, are poorly represented in the list of rare plants for these shrublands. Herbaceous perennials, which by and large show no specialization to fire, represent a disproportionately large portion of the rare plants. In addition to fire, other disturbances such as grazing pose a threat to the native shrubland floras. In contrast to the grazing induced mesquite invasion of southwestern grasslands, in California there is over-whelming evidence that grazing, particularly when coupled with burning, is associated with type conversion of shrublands to grassland. Inferences drawn from historical documents suggest that type conversion from woody shrublands to herbaceous grasslands began with increased fire subsidy provided by Native Americans, continued with the advent of the Spanish pastoral system, increased dramatically in the late 19th century and continues today. Numerous studies show that with a reduction in fire and grazing disturbance, annual grasslands readily return to their former shrubland associations, although it is unlikely that the full complement of species in these communities is readily restored.

Air pollution and vegetation change in California shrublands
Edith B. Allen 1*, Abby Sirulnik 1, Patrick J. Temple 2, Pamela J. Padgett 2, and Andrzej Bytnerowicz 2
1 University of California Riverside, Riverside CA 92521, * edith.allen@usr.edu
2 USDA Forest Service, Pacific Southwest Research Station, Riverside CA 92507

The coastal sage scrub (CSS) vegetation of southern California is converting to annual grasslands, perhaps in part because of air pollution. A comparative analysis of ozone and nitrogen deposition on plants of CSS, chaparral, exotic annual grassland, and coniferous forest shows these vegetation types have different susceptibilities to each pollutant. Historically high concentrations of ozone in the local mountains weakened pines, contributing to tree mortality. Native shrubs had decreased growth in chambers with current-day levels of 150 ppb ozone. The shrubs may escape ozone damage by being physiologically active early in the season, when ozone is lower in concentration. Pines may be more susceptible to ozone than summer-deciduous CSS shrubs and senescent annual grasses. Nitrogen deposition has very different effects because N accumulates on leaf and soil surfaces during the summer. Conifers are more susceptible to leaf-deposited nitric acid because they are physiologically active in summer, while chaparral may be less so because of thick cuticles and reduced summertime activity. Deciduous CSS and senescent grasses are less susceptible to direct leaf damage. However, N becomes available for root uptake after the first fall rains. Soil accumulation up to 87 ug/g extractable N has been measured in CSS shrubland, levels that have caused mortality in the greenhouse. Grasses may escape high soil N damage because of their annual habit, conifers because of a combination of high biomass, lack of N saturation, and microbial immobilization of N in litter. The resistance of chaparral to high N may be due to N immobilization, higher biomass, and slower growth rates than CSS.

A new look at coastal sage scrub- what 70 year old VTM plot data tell us about southern California shrublands
Robert Taylor
Department of Geography, University of California, Santa Barbara, Santa Barbara CA, rtaylor@geog.ucsb.edu

Coastal sage scrub (css) is a drought-deciduous, soft-leafed shrubland frequently dominated by Artemisia californica, Eriogonum fasciculatum, and/or Salvia spp. The Vegetation Type Map (VTM) Survey of California was a depression-era WPA project conducted from 1929 to 1934, under aegis of the U.S. Forest and Range Experiment Station, Berkeley. In addition to mapping vegetation (at about 1:64,000 scale), the survey recorded plot data on plant size, cover, density, and understory species in thousands of plots throughout southern California. The VTM Survey is a valuable and under-utilized historic data set useful for studying css.
The Natural Community Conservation Planning (NCCP) region contains over 1500 plots including 1435 plots covered predominantly by shrubs. The data was collected around 1930, at a rather early point in the explosive urban development of southern California, and thus constitutes a valuable historical snapshot of California plant communities when they were still relatively intact and expansive.
Modern statistical methods applied to this large historic data set provide insights into css community organization. Several types of ordinations and classifications produce convergent results. Gradient analysis shows how css species respond to major environmental gradients and offers tests of general theories of plant community organization. Overlays with modern GIS data show how effective current conservation efforts are at protecting various css types.

Cryptobiotic soil surfaces in coastal sage scrub and other southern California habitats
Peter A. Bowler 1, and J. Belnap 2
1 University of California, Irvine, Department of Ecology and Evolutionary Biology, Irvine CA 92717, pabowler@uci.edu
2 U.S. Geological Survey, Canyonlands Field Station, Moab, UT 84532-0278, jayne_belnap@usgs.gov

Microbiotic or cryptobiotic soil crusts exist worldwide, and are composed of cyanobacteria, lichens, and mosses. They are significant early colonizers which accelerate weathering processes and hold soil from wind or water erosion by binding soil particles together. Soil crusts are important in fixing nitrogen and retaining water in areas where soil nitrogen can be limiting. While soil crusts in coastal sage scrub have not been extensively studied, there is no question that they are important within this community, one of whose characteristics is an open canopy with an extensive annual plant flora. There appears to be a correspondence between the presence of well developed soil crusts and the absence of a dominance of exotics, although causality is not clear. In some habitats biotic soil crusts inhibit the germination of exotic annual grasses. Cryptobiotic crusts in coastal sage scrub and other habitats can be artificially inoculated and microbiotic inoculation should be a part of habitat recovery and restoration plans. Habitat managers are encouraged to be especially protective of areas within preserves having undisturbed soil surfaces and established, healthy soil crusts, because of their significance in sustaining existing communities such as coastal sage scrub. When the soil surface is broken and soil crusts are disturbed, they are slow to recover and there will likely be significant damage to the existing vascular plant community for an extended period of time. In areas with low rainfall and instable soils, complete soil crust recovery can take 250 years. Even seemingly minor disturbances such as bicycle and horse tracks have an impact upon soil crusts. Intact soil crusts should be viewed as a significant habitat asset when selecting new areas for preservation.

Arthropod biodiversity of coastal sage scrub
Richard A. Redak and Jutta C. Burger
Department of Entomology and Center for Conservation Biology, University of California, Riverside, CA 92521, richard.redak@ucr.edu

Arthropods constitute well over one-half of the species of higher life on the planet and are the dominant terrestrial life form on the planet. Unfortunately, very little is known about most of these components of biodiversity. There are an estimated 163,487 species of insects in North America of which only 66% are taxonomically known. Similarly, there are an estimated 35,514 species of North American arachnids of which only 9316 are described; over 73% have yet to be discovered and described. Using both pitfall and vacuuming sampling techniques across a wide geographic range, we provide estimates of the arthropod biodiversity of Southern California's endangered coastal sage scrub (CSS). Here we present a synthesis of our work involving multi-year sampling efforts across over 70 sites ranging from coastal Diegan CSS communities to interior Riversidean CSS communities. Comparisons of the various dominant arthropod communities within and across coastal sage scrub habitats will be provided in an effort to detail the effects of habitat loss on the overall biodiversity of arthropods in these communities. Additionally, using various scenarios and assumptions, we will provide estimates of the hypothetical number of currently endangered insects and arachnids found within CSS.

Status of reptiles and amphibians in the southcoast ecoregion
Robert N. Fisher 1 and Ted Case 2
1 USGS Western Ecological Research Center, Department of Biology, San Diego State University, San Diego, CA 92182, rfisher@sunstroke.sdsu.edu
2 University of California, San Diego La Jolla, CA 92093, case@biomail.ucsd.edu

The southcoast ecoregion of California is host to a large diversity of reptiles and amphibians (>60 species). Many of these species are thought to be at risk due to land use changes over the last 150 years in this region. We have assessed the current status of this fauna utilizing standard techniques across 30+ sites incorporating the majority of habitats in this area since 1995 at long-term monitoring sites. We have collected field data for >36,000 records of 46 species across this five county sampling area. We can now determine which species appear to be at risk even with the planned reserve network that will spread across this region and which species should be adequately protected within this protected matrix of sites. Long-term monitoring of this herpetofauna will be necessary to ensure that changes in the reserves and landscape in this ecoregion will not impact species that currently are stable. Additional studies will be needed to identify adaptive management solutions for species that are currently at risk.

Distributional patterns of birds and small mammals in southern Californian coastal sage scrub
John T. Rotenberry*, William B. Kristan, III, and Mary V. Price
Department of Biology and Center for Conservation Biology, University of California, Riverside, CA 92521, * rote@citrus.ucr.edu

Between 1995-1997 we assessed distributions of birds and small mammals using surveys conducted at 238 points grouped into 22 sites throughout southern Californian coastal sage scrub (CSS) vegetation. At each point we also measured local vegetation and landscape compositional features. Analyses yielded several results. Although distinct at a regional level (compared to other southern Californian vegetation types), CSS is a heterogeneous plant community. Within CSS there were geographical gradients in local vegetation structure and composition, as well as landscape-level vegetation and land-use classification, mainly reflecting north - south and east-west gradients in climate and topography. Several of these gradients include patterns induced by human activities (e.g., exotic forbs and grasses, urbanization). Individual animal species responded to these gradients, with virtually all taxa showing significant associations with local, landscape, or geographical variables. Likewise, several species also exhibited significant urban "edge effects." However, the considerable heterogeneity of individual responses precludes generalization. Patterns of bird and mammal communities were associated with habitat variables, and were correlated with each other; however, species richness of birds and small mammals was uncorrelated. We conclude that a regional reserve system that spans the range of CSS conditions and geographical areas will be necessary if we are to preserve CSS species diversity. However, any system of reserves cannot rely on the local diversity of any single taxonomic group as an indicator of appropriate design, but must be based on meeting the needs of multiple, independent species’ criteria.

Poster Session

Southern California Conservation Strategy: Province-wide forest planning at work
Steven A. Anderson, Jacqueline A. Leonard, Eric Lindroth, and Therese O’Rourke
USDA Forest Service, Cleveland National Forest, San Diego, CA

Natural landscapes are scarce in southern California and continue to shrink, due to loss through development and non-native species invasion. The National Forests contain much of the remaining natural habitat and are home to more than 60 threatened and endangered species. Restoring and maintaining these habitats, and the plant and animal populations they support, is an enormous challenge, particularly given the growing demand for recreation opportunities and open space in the southern part of the state.
The Southern California Conservation Strategy is an integrated effort by the Angeles, San Bernardino, Cleveland, and Los Padres National Forests to enhance ecosystem health and protection of species while providing recreation and other activities on National Forests. The current southern California Forest Management Plans are 10 to 15 years old and have not been revised or significantly amended. During this time, new issues and new information common to all four Forests have emerged, and the Forest Plans need to be updated in a coordinated manner.
Collaboration with scientists and the public will be an important part of the Forest Plan revision process, sharing the latest information on species and habitats as well as innovative ideas for management of the land. An Environmental Impact Statement (EIS) for all four Forests that outlines alternatives for addressing these issues will be developed, with a draft expected to be released for public review in 2002.

A conservation strategy for the Northern Channel Islands
Tim Coonan 1, Sarah Chaney 1, Kate Faulkner 1, Lauren Johnson 2, Kathryn McEachern 3, Connie Rutherford 4, Cathy Schwemm 1, and Tim Thomas 4
1 Channel Islands National Park, Ventura, CA 93001
2 Niobrara/Missouri National Scenic Riverways, O'Neill, NE 68763
3 U.S. Geological Survey-BRD, Channel Islands Field Station, Ventura, CA 93001, kathryn_mceachern@usgs.gov
4 U.S. Fish & Wildlife Service, Ventura CA 93003

It is not unusual in southern California for several rare taxa to occur together on the same land management unit. Yet, even in these systems conservation and recovery management plans traditionally target single species at the population level. Single-species management is not an effective strategy where rare and unusual taxa occur together. There are fourteen Federally listed plant taxa in the northern Channel Islands, ranging from annuals to shrubs. Although they each have unique biological requirements, they are all suffering from the ecological effects of sustained overgrazing. Here, it makes sense to manage the ecological system for recovery. Management at the landscape level will benefit the rare species, as well as a host of other native plants and animals that are of concern. In 1994, scientists from the National Park Service, U.S. Fish and Wildlife Service, and U.S. Geological Survey-BRD formed a team to design recovery of plant communities and ecosystem processes that sustain the rare island taxa. The team developed management strategies using information on the conditions of island plant communities and plant and animal populations. Specific short-term and long-term recovery goals were developed, so that progress toward recovery can be measured. Several of the management strategies are currently being implemented. Their success will be evaluated at the ecosystem (litter accumulation, nutrient cycling, fire frequency), plant community (native and non-native cover, shrub density), and population (fecundity, recruitment, mortality) levels.

South Coast Wildlands Project -- vision maps for landscape connectivity
Rich Hunter
Talon Associates, Bodega CA 94922

The southwestern California region is globally recognized for its unique natural characteristics, intersection of varied ecosystems, and diverse assemblage of species. At the same time, the region's spectacular wildlands and biodiversity are among the most threatened in North America. While Natural Community Conservation Plans (NCCP) have brought disparate interests together to protect some key areas of the most intensely threatened habitats, they have fallen short of offering a vision for regional landscape connectivity. The South Coast Wildlands Project is developing a strategy to complement on-going conservation efforts that focuses on habitat conservation for large mammalian carnivores. Our approach emphasizes the protection of core wildlands and restoration of landscape connectivity. We selected a suite of focal species with demanding needs for connectivity and core habitat. Using GIS, we analyzed the opportunities to provide for the spatial and ecological requirements for cougar, bobcat, and steelhead. With these maps, we identified a reserve network of conservation areas throughout the region. Key connectivity zones at the regional scale were evident by comparing the focal species habitats with various human disturbance factors, including land use and roads. The results provide an important regional perspective for maintaining and restoring ecological integrity in the South Coast region. Next steps include further collaboration with federal, state, and local agencies and organizations to identify connectivity zones at finer scales and provide site-specific recommendations for implementing the vision. We welcome comments on these draft maps.

The California Natural Diversity Data Base
Darlene McGriff
California Department of Fish and Game, Sacramento, CA, dmcgriff@dfg.ca.gov

Environmental changes, associated with the state's population growth and correlated development are contributing to the decline of native species. In 1979, to help conserve California's biological diversity, the Department of Fish and Game and The Nature Conservancy established the California Natural Diversity Data Base (CNDDB) within the Department of Fish and Game. The CNDDB is a continually updated, computerized inventory of location information on California's rarest plants, animals, and natural communities. The CNDDB collects data from a wide variety of sources and makes it available in a standardized format. The CNDDB currently contains over 35,000 records on more than 3,000 native species, and communities. State-of-the-art computer mapping is used to maintain the CNDDB. The CNDDB uses ESRI Arc/Info geographic information system (GIS) software and Oracle relational database. The GIS allows us to map and analyze the CNDDB information in a myriad of ways. RareFind2 is a PC application of the CNDDB. It contains all of the textual data in the CNDDB in a versatile, searchable database. It can be used alone or linked with the ESRI GIS application ArcView for even greater flexibility. Consultants, planners, state and federal agencies, and conservation groups use the CNDDB to determine where declining species and natural communities are known to occur. By providing information that can help in making wise land-use and resource management decisions, the CNDDB is one of California's most valuable conservation tools.

Spatial and temporal variation in ephemeral pool crustacean communities
Janette Holtz 1, Marie A. Simovich 1, and Thomas Philippi 2
1 University of San Diego, San Diego, CA
2 Savannah River Ecology Lab, University of Georgia, Drawer E Aiken, SC

Understanding the spatial distribution of biodiversity among pools is crucial for effectively protecting, monitoring, and restoring vernal pools. Crustacean communities in eight vernal pools in San Diego County, California were sampled over three years with differing rainfall amount and pattern. In 1994, rains occurred late but were moderate in quantity; species richness ranged from 1 to 22 species. 1998 was a high rainfall El Niño year, and pools varied from 0 to 15 species. 1999 was a low rainfall La Niña year, and pools contained 4 to 7 species. No spatial pattern was seen among neighboring pools. Longer-lived pools had more species including the more rare species; smaller pools included the more common taxa. Diversity within pools varied between years, although the highest rainfall year did not result in the highest diversity. These data indicate the necessity of surveying multiple pools over a period of several years to establish baseline data for these complex communities. Furthermore, adequate monitoring of restored or created pools must extend over several pools and several years.

Bee diversity associated with Limnanthes floral patches in California vernal pool habitats
Joan M. Leong 1,2 and Robbin W. Thorp1
1 Department of Entomology, University of California, Davis
2 Department of Biological Sciences, California State Polytechnic University, Pomona

Like other wetland habitats, it is estimated that approximately 90% of vernal pool habitat has been lost in California. In southern California, losses are estimated to be even greater. The flora of these endangered habitats is reasonably well known, especially the spring flowering annuals that are found in, or at the margins of vernal pools (i.e. Blennosperma, Limnanthes, Lasthenia and, Downingia species). However, the insect pollinator fauna associated with these floral species is much less well known, and what work has been done has been limited primarily to the northern central valley region. One of our studies examined the bee fauna associated with floral patches of Limnanthes douglasii rosea using a new sampling or monitoring method . We used colored pan traps to assess the species richness and abundance of the bee fauna associated with seven L. douglasii rosea patches in the spring of 1996 near Sacramento, CA. Our study revealed that over 30 bee species were foraging in these floral patches over a 3 week period. The most abundant species was a native, solitary species, Andrena (Diandrena) limnnathis, a specialist on the pollen of L. douglasii rosea. Approximately two-thirds of the bee species belong to the family Andrenidae, many of which are thought to be endemic to vernal pool habitats. These results indicate that the number of bee species associated with L. douglasii rosea patches can be suprisingly high during discrete periods. We propose that a similar level of bee diversity may occur in southern California vernal pool habitats.

Habitat ephemerality and hatching fractions of a diapausing Anostracan (Crustacea: Branchiopoda)
Marie A. Simovich 1, Thomas E. Philippi 2, Ellen T. Bauder 3, and Jacob A. Moorad 4,5.
1 Department of Biology, University of San Diego, San Diego CA 92182
2 Savannah River Ecology Lab, University of Georgia
3 Department of Botany, San Diego State University, San Diego CA 92182
4 Department of Marine and Environmental Science, University of San Diego
5 Department of Biology, Indiana University

Diapause allows aquatic organisms to survive periods of drydown in intermittent pools. However, often not all of the individuals hatch in response to a filling event. This prolonged diapause can be a bet-hedging adaptation to unpredictability in the duration of filling events. Under the simplest bet-hedging model of selection on prolonged diapause, the fraction of eggs hatching in any filling event should approximate the fraction of filling events lasting long enough for successful reproduction. We quantified filling durations in 7 vernal pools in San Diego County inhabited by the endemic fairy shrimp Branchinecta sandiegonensis (Branchiopoda: Anostraca) for all winter and spring events from 1983-1996. For any given rainfall event, larger, deeper pools held water longer than smaller, shallower pools. However, the distributions of filling durations did not differ significantly among these pools, so selection should be similar across pools. Approximately 28% of the filling events lasted 17 days or longer, the developmental time to first reproduction (under field conditions) in B. sandiegonensis. Laboratory hatching experiments determined a maximum hatching rate of 28% at 10oc, with lower hatching percentages at higher and lower temperatures. The close fit between the probability of adequate filling duration and the hatching fraction, and the similar distributions of filling durations among these pools, suggest that creating pools with hydrology suitable for B. sandiegonensis may require care to match the filling durations B. sandiegonensis appears adapted to.

Surveys for California red-legged frog and arroyo southwestern toad on the Los Padres National Forest
Thomas G. Murphey, Valerie K. Hubbartt, and Richard J. Raymond
USDA Forest Service, Los Padres National Forest, Santa Maria, CA 93453

USDA Forest Service biologists are conducting biological surveys throughout the Los Padres National Forest for the federally listed California red-legged frog (Rana aurora draytonii) and arroyo southwestern toad (Bufo microscaphus californicus). These surveys are being done to determine potential impacts of Forest Service activities on these threatened and endangered species. Historical locations and areas having suitable habitat for both species are visited to confirm occupancy. Day and night surveys are conducted for both species and when present, locations of individuals are mapped. Sites known to have frogs or toads present are monitored for breeding and possible impacts of Forest Service activities. Potential impacts to frogs and toads include, roads, trails, campgrounds, off highway vehicles, grazing allotments, and introduced species. Future surveys will be conducted to further identify areas of potentially suitable habitat. Inventorying and monitoring will continue where Forest Service activities may result in adverse impacts on the listed species.

Impact assessment and numbers of Oncorhynchus mykiss on the Los Padres National Forest
N. Kautzman, C. Slaughter, T. Weddle, T. Wallace, and J. Uyehara
USDA Forest Service, Los Padres National Forest, Goleta CA

Declines in central and southern California steelhead populations have resulted in federal listing of Oncorhynchus mykiss. One objective of 1999 monitoring surveys was to assess if management practices on the LPNF are impacting anadromous streams. A second objective was to estimate the numbers and size classes of O. mykiss (resident and anadromous). Potential impacts to the streams come from roads, grazing allotments, recreation, fire suppression, and resource extraction. To assess habitat quality we surveyed 28.2 km of anadromous streams. Reaches with potential impacts were surveyed along with an upstream reference reach. Preliminary analysis did not find differences between the mean values of impact and reference reaches in terms of sedimentation, embeddedness, instream cover, or riparian vegetation. However, based on these same values, many of the streams are considered "at-risk" or "nonfunctional" using standards developed by National Marine Fisheries Service. The streams tend to have high temperatures (sometimes exceeding the upper lethal temp for O. mykiss), substantial sedimentation/embeddedness, and low amounts of instream cover (primarily lacking large woody debris). Stream conditions may be normal for our forest when geology, weather, and riparian vegetation are considered.
Despite the less-than-optimal conditions, we observed O. mykiss in size classes from 2.5 cm to 21.0 cm in substantial numbers during snorkeling surveys. The presence of multiple size classes of O. mykiss indicate that recruitment and survivorship are presently occuring on the LPNF. The ability to thrive in less-than-optimal conditions has been noted in other O. mykiss populations.

Monitoring the Shay Creek stickleback, a locally endangered fish
James Malcolm and Students
Department of Biology, University of Redlands, Redlands CA 92373

The Shay Creek Stickleback (SCS) is a genetically distinctive population of the threespine stickleback (Gasterosteus aculeatus). It has been recognized as a population of the federally listed unarmored threespine stickleback (G. a. williamsoni) (Fed. Reg. 1996 vol 61 (132) p36022). Few of the fish survive in their original habitat in Shay Creek in the San Bernardino Mountains. In 1988 approximately 350 SCS were translocated to Sugarloaf Pond where a healthy population has persisted. Sugarloaf Pond lies at 6700ft on the North side of the Santa Ana Drainage. The pond is approximately 30m by 15m with abundant aquatic vegetation. The population in Sugarloaf Pond has been monitored since 1991. Unbaited minnow traps are placed at fixed locations several times a year. The number of fish entering the traps per hour is recorded together with some physical measurements (standard length, depth, lateral plates and breeding status). The annual breeding cycle is well established. Breeding males have been recorded in traps from January until July. Gravid females are found from February to July. Young of the year are first recorded in traps at about 18mms standard length in July. Population monitoring is hampered by very high variance in the number of fish entering a trap. It appears that the population is at a maximum in the late summer.

Monitoring the effects of natural and anthropogenic habitat disturbance on the ecology and behavior of the San Diego coast horned lizard, Phrynosoma coronatum blainvillei
Tandora D. Grant and Allison C. Alberts*
Ecology and Applied Conservation Division, Center for Reproduction of
Endangered Species, Zoological Society of San Diego, P.O. Box 120551, San Diego, CA 92112
* aalberts@sandiegozoo.org

Since 1995, we have been monitoring San Diego coast horned lizards on the Southwestern Riverside County Multi-Species Reserve near Temecula, California. Our studies have focused on horned lizard populations occupying 1) undisturbed Riversidian sage scrub, 2) sage scrub naturally disturbed by fire, and 3) sage scrub anthropogenically disturbed by historical cattle grazing. Although horned lizards occupy all three habitats, adult density appears to be lower in grazed habitats than undisturbed and burned habitats. Vegetation transects show that plant densities are higher, individual bushes are larger, and the proportion of non-native species is lower in undisturbed and burned habitats than in grazed habitats. These differences appear to have important ecological consequences for horned lizards. Male horned lizards in undisturbed habitats are larger than those in burned and grazed habitats. While females in undisturbed and burned habitats do not differ in body size, they significantly exceed females in grazed habitats. Analysis of horned lizard scat samples reveal that these size differences may be the result of an impoverished prey base in disturbed habitats, particularly those that have been grazed. Through radiotelemetry, we have documented differences in movement patterns and number of conspecifics overlapped that may be related to the ability of horned lizard to forage effectively in undisturbed, burned, and grazed habitats. Our data to date suggest that horned lizards in disturbed habitats are subject to greater energetic costs and environmental stress than those in undisturbed habitats, and that these effects are magnified in anthropogenically disturbed habitats relative to naturally disturbed ones.

Atmospheric nitrogen deposition and habitat alteration in terrestrial and aquatic ecosystems in southern California: implications for threatened and endangered species
Mark Fenn 1, Mark Poth 1 and Thomas Meixner 2
1 USDA Forest Service, Pacific Southwest Research Station, Forest Fire Laboratory, 4955 Canyon Crest Drive, Riverside, CA 92507
2 Department of Environmental Science, University of California, Riverside, CA 92521

Recent studies in the transverse ranges (including Class I Wilderness areas) demonstrate the linkage between atmospheric nitrogen (N) inputs into montane watersheds and nitrate levels in drainage waters. Nitrate concentrations in streamwater in southern California are the highest in North America for wildland watersheds. High nitrate in runoff is a result of excessive ecosystem enrichment with N from atmospheric deposition. N-saturated forests are analogous to over-fertilized agricultural fields with high nitrate runoff. Vegetation in N-saturated ecosystems contains high levels of N, and excess N also builds up in litter and organic matter, especially with fire suppression. Stand densification is likely to be exacerbated by N deposition. Due to the interaction of N deposition with land management practices it is possible that past, present, and future land management practices (including fire suppression, introduction of invasive species, and forestry practices) could minimize or exacerbate the adverse effects of N deposition on terrestrial and aquatic ecosystems. Hydrologic flowpaths in a watershed also influence the impact of atmospheric N deposition on aquatic ecosystems. Excess N in terrestrial, riparian and aquatic habitats dramatically changes the chemical environment of these habitats and has high potential to upset the normal communities of vegetation, microbes, and fauna; either via direct effects or via cascading effects on the food chain. Recent evidence suggests that elevated nitrate levels in pond water may be toxic to larvae of several Western frog species which are in decline. The effects of high nitrate on key species is a neglected area of research that should be addressed.

Developing a weed control strategy for Channel Islands National Park
Sarah Chaney 1 and Kathryn McEachern 2
1 Channel Islands National Park, 1901 Spinnaker Drive, Ventura, CA 93001
2 U.S. Geological Survey-BRD Channel Islands Field Station, 1901 Spinnaker Drive, Ventura, CA 93001, kathryn_mceachern@usgs.gov

Much of southern California was used for livestock production throughout the last century, resulting in widespread invasion of alien taxa. The five islands comprising Channel Islands National Park are no exception. Nearly one-quarter of the flora is alien, Mediterranean annual grassland constitutes 25 to 50% of the land cover on each island, and endemic plant populations are threatened by alien plant invasion. Clearly, the park needs to develop a sustainable and affordable knowledge-based system for weed management. The National Park Service and U.S. Geological Survey-BRD are developing a weed management plan for the park. The plan uses existing information and field surveys to prioritize species and locations for control. Literature reviews have been completed for 85 weeds of the islands, providing information on weed biology, ecological effects and control techniques. Alien species distribution and abundance have been mapped in the field, and the data are being compiled into an ArcInfo/Access database. This information will be used in a computer-based decision model to develop a multivariate overview of each species’ innate ability to be a pest, given its ecological impact on each island. Model results will be used to develop the weed management plan. Initial results show that the threat any weedy species poses depends very much on its ecological context, so that the management priorities will differ among islands. The choice of the management unit is a crucial step in developing a weed control plan, and an effective plan cannot be developed without basic information on ecology and abundance.

Patterns and processes of arthropod community succession after a fire
Jutta C. Burger 1, M. A. Patten 2, J. T. Rotenberry 2,3, and R. A. Redak 2,3
1 Department of Entomology, University of California, Riverside, CA 92521
2 Department of Biology, University of California, Riverside, CA 92521
3 Center for Conservation Biology, University of California, Riverside CA 92521

We surveyed arthropods after a disturbance by fire in southern California coastal sage scrub to investigate: (1) the degree to which arthropods had recolonized burned sites, (2) the pattern of post-fire succession across arthropod orders and guilds, and (3) the relative strength of patterns of recolonization between arthropod orders, families and guilds. We sampled vegetation and collected arthropods from 12 burned and 12 unburned sites using pitfall traps, malaise traps, and vacuum samples beginning three years after a fire. Arthropods were collected at three-month intervals over the course of two years and were subsequently counted and identified to family and guild. We associated families with the following guilds: detritivore, herbivore, parasitoid, pollinator, predator, scavenger, and hematavore or vertebrate parasite. We found no significant difference between burned and unburned sites at the level of order or family, but burned sites had a distinct and predictable guild structure. Scavengers were most abundant and detritivores were among the least abundant in burned sites, whereas detritivores were significantly more dominant in undisturbed sites. This study supports results of an earlier study (Patten et al., in prep) and strongly suggests that arthropod recolonization follows similar rules that vegetational succession does, as represented by changes in the importance of different functional groups or guilds at a site over time. In addition, results support the hypothesis that regional processes determine overall community structure, but local processes (such as disturbance by fire) determine the presence or absence of specific members of a community.

Diptera community composition and succession following habitat disturbance by wildfire
Michael A. Patten 1, Jutta C. Burger 2, Thomas A. Prentice 2, John T. Rotenberry 1,3, Richard A. Redak 2,3
1 Department of Biology, University of California, Riverside, CA 92521
2 Department of Entomology, University of California, Riverside, CA 92521
3 Center for Conservation Biology, University of California, Riverside, CA 92521

Both biogeographic and local processes determine composition and succession of biotic communities. To infer processes involved, we compared patterns of richness and community composition of families of Diptera at 12 burned and 12 unburned sites of coastal sage scrub at Lake Skinner, California. Sites were sampled at 3-month intervals in 1996 and 1997. Fluctuations in richness over time were parallel in burned and unburned sites, permitting us to pool data over all sampling periods. Whereas burned and unburned sites fell out along a clear gradient when ordinated by vegetative characteristics, they were not discernable as such on the basis of relative abundance of Diptera families. Thus, the overall Diptera community recovered more quickly than did vegetation. However, there remained a strong association between abundance within families of Diptera and vegetation on the plots, indicating the burn had effects on at least some components within the community. Recolonization of burned plots followed a predictable pattern, with generalized scavengers recolonizing fiirst, followed by animal feeders (predators, parasitoids, and hematavores), then by plant feeders (herbivores and pollinators), and with detritivores recolonizing most slowly. These results support the hypothesis that climate, seasonal fluctuations, and geography of a region determine overall community composition (i.e., communities on plots were more similar than different), but disturbance alters local distributions within the community (i.e., by altering microhabitat, which affects certain taxa more than others).

A cautionary note on the need for fire management in some California ecosystems
Hartmut S. Walter and Teresa Brennan
Department of Geography, UCLA, P. O. Box 951524, Los Angeles, CA 90095-1524

The fire paradigm has been so successful that it must raise suspicions in experienced ecological minds: can one variable really be trusted to regulate and organize the high complexity of habitats, bio-landscapes, and biotic communities? Is there any evidence that the popular fire management policies of our public agencies actually threaten to reach areas and ecosystems that might persist well or better without any regular or prescribed fire events? The purpose of this paper is to introduce and discuss evidence from the Channel Islands, coastal San Diego County, and the San Jacinto Mtns. that demonstrates (1) the presence of fire evaders in California, (2) the unique composition of "ancient chaparral" communities, and (3) the efficacy of non-fire factors in forest renewal. The case of the Bishop pine (Pinus muricata) on Santa Cruz Island indicates no need for fire in germination processes and stand replacement. Observations, transects, and germination experiments support the concept that this coastal species and perhaps other closed-cone pine and cypress species in California do not benefit from most types of wildfire. Maritime chaparral communities that have not burned for several "fire generations" constitute unique and valuable habitats that deserve protection from fire. Mixed conifer-oak forest and ecotonal chaparral stands seem to thrive in a San Jacinto wilderness without fire. Where fire has devoured a mature ecosystem, succession takes much longer than predicted by traditional fire ecology. The implications of these findings are discussed in terms of the short- and long-term conservation management needs of the rich and complex biodiversity of Southern California.

The effects of wildfire on the density and reproductive effort of the California gnatcatcher
William O. Wirtz, II and Sarah C. Chamberlain
Biology Department, Pomona College, Claremont, CA

The effects of fire on the ecology of the California gnatcatcher, Polioptila californica, and associated bird species, have been investigated since 1992. Both burned (experimental) and unburned (control) sites are surveyed regularly during the breeding season; all gnatcatchers, nests, eggs, nestlings, and fledglings are recorded, individual territories are mapped, and the distribution of territories is also mapped. We have determined that gnatcatcher pairs which can establish a territory on burned sites exhibit the same amount of reproductive effort as birds on unburned sites. However, the density of birds on burned and unburned sites is quite different, and has not changed significantly during the eight year study period.

Effects of fire on rodent populations in California coastal sage scrub
William O. Wirtz, II 1, Audrey L. Mayer 1, Mary M. Raney 1, and Jan L. Beyers 2
1 Biology Department, Pomona College, Claremont, CA
2 Pacific Southwest Research Station, USDA Forest Service, Riverside, CA 92507

Coastal sage scrub has been largely converted to agricultural and urban uses; less than 20% of the original habitat remains. It is subject to frequent anthropogenic fire. Several resident vertebrate species have become candidates for Federal endangered species listing. The effects of fire on rodent populations in sage scrub are not well documented. During 1995 and 1996 we censused rodent populations on burned and unburned sites in San Diego and Riverside counties. Eleven rodent species were found. Three species, Chaetodipus c. femoralis, C. f. fallax, and Neotoma l. intermedia, are species of special concern in California. The two pocket mice are separated geographically, with C. californicus present along the coast and C. fallax inland. C. fallax is more numerous on burned sites, while C. californicus seems to undergo seasonal cycles. Effects of fire on rodents are similar to that reported by Wirtz for chaparral. Cricetid rodent species seem limited in distribution by habitat variables. Peromyscus californicus and woodrats require shrubs; they are absent from postfire associations lacking shrubs. P. eremicus is an arid habitat specialist, and prefers micro- habitat with at least some rocks and shrubs. P. maniculatus is a generalist, and thrives in disturbed habitats. It is more common following fire than otherwise in soft or hard chaparral communities. The occurrence of Mus musculus at Camp Pendleton at some times of year in extremely high numbers, and especially on recently burned sites, is of management concern, particularly since it occurs at sites with species of special concern

Concurrent Session III. Riparian Habitats

Monitoring water quality in an urbanized watershed: a case study from the Santa Ana Basin, CA
Kenneth Belitz
U.S. Geological Survey, Water Resources Division, Santa Ana Basin NAWQA, 5735 Kearny Villa Rd, San Diego, CA 92123, kbelitz@usgs.gov

The U.S. Geological Survey's National Water Quality Assessment Program (NAWQA) is monitoring water quality in streams and aquifers in the Santa Ana Basin of southern California.
The drainage area of the Santa Ana River is about 2700 square miles, including parts of Orange, Riverside, and San Bernardino counties. Land use in the Santa Ana Basin is about 35% urban, 10% agricultural, and 55% open space, primarily steep mountain slopes. The basin is home to more than 4 million people who not only rely on water resources that originate within the basin, but also on water imported from northern California and the Colorado River.
Urbanization dominates the hydrologic cycle in the Santa Ana Basin. The Santa Ana River and many of its tributaries are partially or completely channelized, and in many cases concrete-lined.
Under base-flow conditions, these channels typically convey treated waste-water with a small component of urban base-flow. Under storm-flow conditions, these channels convey run-off from urban and agricultural areas as well as some run-off from the surrounding mountains. Storm-flows from head-water tributaries are typically diverted to detention basins which also serve as ground-water recharge facilities.
In October 1998, the Santa Ana NAWQA project entered its "high intensity phase" which will last for three years. As part of this high intensity phase, we are conducting a "distribution and occurrence survey" to assess water quality conditions; these activities include sampling of stream-water, bed-sediment and tissue, and ecologic surveys at selected sites. Periodically, results of these activities are posted on our web site: http://water.wr.usgs.gov/sana_nawqa/

Biodiversity and conservation of the freshwater fishes of southern California
Camm C. Swift 1 and Jonathan N. Baskin 2
1 Consultant and Emeritus Associate Curator, Natural History Museum of Los Angeles County
2 Biological Sciences Department, California State Polytechnic University Pomona and San Marino Environmental Associates

About ten taxa of native freshwater fishes occur in the coastal drainages of southern California, a freshwater and an anadromus lamprey, steelhead (including rainbow trout), one sucker, two minnows (a chub and a dace), one stickleback (with three or more distinct conservation units), and perhaps two sculpins. Most of these, except one minnow and the sculpins, are concentrated the Los Angeles Basin, i.e. the Los Angeles, San Gabriel, and Santa Ana River systems. One form of stickleback occurs in the upper Santa Clara River, another in near Big Bear and a third in the lower portions of several rivers. The two sculpins are native only in steams north of Point Conception. Otherwise north and south of the Los Angeles Basin only steelhead, anadromus lamprey, and stickleback are native. All of these fishes are temperate or boreal taxa adapted to cool or cold, clear, flowing streams with a mixture of rock, gravel and sand substrate. Only the stickleback prefers low gradient, slower flowing marginal stream habitat. The life histories of most of these species involves spawning in clean gravels in upstream areas, movement or drift of young downstream, and subsequent dispersal with growth. In southern California, all of these fishes are at or near the southern limits of their distribution.
Conservation measures should maintain and restore: cool temperatures, sediment free substrates, clear flowing water, a natural hydrograph, a free flowing, meandering stream in the lowlands, natural riparian vegetation. Factors to avoid include: exotic species of fishes and amphibians, especially predators; impounded (ponded) water as habitat for exotic predators; barriers to movement along streams; translocation of individuals between rivers basins; population sinks; fine sediments; channel modifications, especially narrow, hard sided banks; water quality modifications. Special considerations are need for the stickleback, such as maintenance of natural barriers, due to the subspecific differentiation of the units. An organized effort to collaborate on such improvements needs to be concentrated where these native fishes occur today. The lessons learned from these core systems can then be applied to restoring habitats and returning fishes to other historically viable habitats in southern California, as outlined in the Recovery Plan for the Unarmored Threespine Stickleback.

Upland habitat use by California amphibians
Norman J. Scott, Jr.
U.S. Geological Survey, Western Ecological Research Center, San Simeon, CA 93452, norman_scott@usgs.gov
Concern for the well being of amphibian populations has never been greater, and details of the use of upland habitats by California's frogs, toads, and salamanders is becoming increasingly important to the management and regulatory agencies charged with their protection. Few studies have dealt with the nonbreeding distribution of North American amphibians, and fewer yet are relevant to faunas living in California's unique Mediterranean climate.
Most plethodontid salamanders are not tied to water sources, and they may be found in suitable habitat almost anywhere outside of the deserts. The few pertinent studies of other California amphibians documented few movements away from water greater than 100m, although Taricha rivularis displaced up to 8 km found their way home. Observations in other parts of North America indicated that juveniles were the main dispersers, and adults were showed fidelity to a breeding site.
Recently completed radiotracking studies of Rana aurora draytonii in the Coast Range documented several movement patterns. Some individual frogs stayed in the breeding pond all year, but many made a regular migration of 50-3000 m between the breeding site and summer habitat. Movements >200 m were stimulated by metamorphosis, rainfall, postbreeding dispersal, and drying or increased salinity of the summer site.
With a few taxonomic exceptions, (plethodontids, Ascaphus truei, Rhyacotriton variegatus), most individuals of California amphibians exhibit the same four phase movement pattern: Juvenile dispersal, movement to breeding sites, movement to summer-fall habitat, and local forays, most of which involve travel in upland habitats.

Status of sensitive riparian birds in southern California
Barbara E. Kus
U.S. Geological Survey, Western Ecological Research Center, Department of Biology, San Diego State University, San Diego, CA 92182, bkus@sunstroke.sdsu.edu

Managing riparian habitat for sensitive birds is a conservation priority in southern California. Most of the management during the last 15 years has focused on protection of the endangered least Bell’s vireo and southwestern willow flycatcher, although it has incidentally affected other declining riparian species similarly threatened by habitat loss and cowbird parasitism. Cowbird control has been shown to reduce or eliminate parasitism of both vireos and flycatchers and thereby enhance productivity; however, while vireos have consequently increased in number and range, growing from 300 territorial males at the time of listing in 1986 to over 2000 today, flycatchers have not, suggesting that factors other than parasitism are limiting this species. Other sensitive hosts such as yellow warblers, blue grosbeaks, and yellow-breasted chats appear to be increasing, but quantitative pre-trapping data are largely lacking and the extent of population increases in these species is unknown. Habitat restoration and creation through plantings has been shown to provide suitable nesting habitat for vireos, offering a potential means for expanding habitat availability. Future research related to protection of vireos should evaluate the need for, and potential alternatives to, continued cowbird control in its present form, and the extent to which current restoration practices are producing self-sustaining ecosystems capable of providing long-term benefits to vireos as well as the full complement of native riparian species. Research on flycatchers should emphasize identification of factors limiting population growth, quantification of demography and dispersal to provide a better understanding of population dynamics, and comprehensive surveys to ascertain the actual distribution of flycatchers in California.

Arundo control effectiveness and system response
Dawn M. Lawson 1, Jesse A. Giessow 2 and Jason H. Giessow 2
1Southwest Division, Naval Facilities Engineering Command, San Diego CA 92132, lawsondm@efdsw.navfac.navy.mil
2 Dendra

Large scale Arundo control has been in progress on Camp Pendleton for approximately five years. To date treatment has been initiated and is in various stages of completion on over 16 miles of the Santa Margarita River. Based on our results we are using primarily two methods of control: foliar application of herbicide (no cutting) and mechanical removal. We have found foliar application without biomass removal to be the most cost effective method of control. However, due to concerns about leaving too much dead Arundo biomass in the river system we also mechanically control Arundo. In this method the stalks and most of the root masses are extracted the first year with herbicide applications to control scattered resprouting the following years. The cut and spray method is used in situations where overspray from foliar applications could potentially damage endangered species habitat. Vegetation monitoring transects have been established in areas where Arundo has been controlled to document the effectiveness of the different treatments and the succession of plant communities in relation to the Arundo control method used and floodplain position (channel, floodplain and terrace). We will report on methods, results and costs.

Impacts of exotic predators on the stream-breeding amphibians of the Santa Monica Mountains
Lee B. Kats
Natural Science Division, Pepperdine University, Malibu, CA 90263, lkats@pepperdine.edu

Biodiversity in North American lakes, rivers and streams is declining. One of the primary causes of loss of biodiversity in these systems is the introduction of exotic species. For the last 10 years we have been studying the stream-breeding amphibians of the Santa Monica Mountains of Southern California. Our studies have indicated that exotic species are negatively affecting these animals. Of the three commonly occurring stream-breeding species, Hyla cadaverina, Hyla regilla and Taricha torosa, H. cadaverina and T. torosa appear most vulnerable to exotic predators. Exotic predators prey on amphibian eggs and newly hatched larvae. Disturbances by exotic predators to amphibian populations are likely long term. Negative impacts to amphibians are also likely indicators of impacts to other aquatic organisms as well. There does not appear to be a mechanism for removing exotics once they are established in a stream. Biologists and policy makers should consider whether resources should be dedicated toward exotic removal or focus on the prevention of new introductions. Current law allows for the possession of exotic predators for use in mosquito control (mosquitofish) and as fish bait (crayfish). New policies should be established that would more closely regulate the distribution of exotic predators in California. In addition, new policies to conserve stream-breeding amphibians must focus on acquiring and preserving streams where exotic predators have not yet established.

Pesticide concentrations in stormflow in the Santa Ana River, southern California
John A. Izbicki
U.S. Geological Survey, Water Resources Division, Santa Ana Basin NAWQA, 5735 Kearny Villa Rd, San Diego, CA 92123

The Santa Ana River is the largest river in the densely populated coastal area of southern California, and drains about 2,670 square miles. Water from six storms, between October 1996 and February 1998, was sampled at two sites--below Prado Dam and at the diversion downstream from Imperial Highway. Imperial Highway is 11 miles downstream from Prado Dam. At Imperial Highway, almost the entire flow in the river is diverted into ponds where it infiltrates and recharges underlying aquifers. About 2 million people depend on these aquifers for water supply. Hydrograph separation was used to estimate runoff and pesticide contributions between the two sites. Sample water was analyzed for 87 pesticides using U.S. Geological Survey (USGS) solid-phase extraction methodologies. These methods have detection limits in the part per trillion range, which is several orders of magnitude lower than standard methods used for drinking-water analyses. Using these USGS methods 25 pesticides were detected below Prado Dam and at the diversion downstream from Imperial Highway, and 62 pesticides that were included in the analyses were not detected. The concentration of most compounds increased during stormflow, however, all 25 compounds were detected at concentrations less than their respective Maximum Contaminant Levels (MCL) and only diuron, carbaryl, and simazine were detected at concentrations greater than 1 microgram per liter. Increases in diazinon, malathion, and chloropyrifos concentrations during stormflow were larger in runoff from areas downstream from Prado Dam, whereas increases in simizine and diuron concentrations were larger during runoff from areas upstream from Prado Dam. In general pesticides, such as chlorpyrifos, malathion, diuron, DCPA, simazine, and carbaryl, that have high reported use in the area have a high frequency of detection in stormflow.

Los Padres Riparian Conservation Strategy: an attempt at managing for biodiversity at the ecosystem level
Maeton Freel
USDA Forest Service, Los Padres National Forest, Goleta CA 93117, mfreel/r5_lospadres@fs.fed.edu

Back in 1990, the Los Padres National Forest, in cooperation with Dr. Samuel Sweet of the University of California at Santa Barbara, initiated a life history study of the Southwestern Arroyo Toad (Bufo microscaphus californicus).
After two years of intensive surveys and study Dr. Sweet produced the first comprehensive life history study of this species, along with a number of management recommendations aimed at correcting adverse impacts on this species from ongoing Forest use activities. As a result of this report the Forest initiated the development of a Conservation Strategy for the toad.
After only a short time it became evident that the activities affecting the toad and the corrective actions being identified to avoid or minimize these effects would also benefit a number of other rare species which occur in the same habitats. Therefore the Forest decided to expand the scope of the strategy to cover the entire aquatic-riparian ecosystem on a Forestwide basis.
A total of sixteen species, both plant and animal, were eventually identified as being dependent on the riparian-aquatic ecosystem. This assemblage included four birds, two reptiles, three amphibians, four fish and three plants which were classified as threatened, endangered or sensitive species.
The assessment of impacts on this ecosystem identified twelve activities for which management direction was to be developed. These major activities included such things as livestock grazing, exotic species introductions, water management, recreation uses, minerals extraction, and road construction and maintenance.
The development of the strategy included over two years of coordination with other state, and Federal resource management agencies and with each of the major program areas across the Forest.
The result of these efforts was the Forestwide Riparian Conservation Strategy which was finalized in 1994. The Strategy includes a number of elements including: A. Planning, Inventory and Implementation; B. Partnerships; C. Organization and Training; D. Program and Budget Considerations; E. Project Quality Control; and F. Monitoring and Evaluation.
Some of the results of working under the Strategy for the past six years have been the development of a General 404 Permit with the Army Corps of Engineers for all Forest road stream crossing maintenance and repair; A Memorandum of Understanding with the U.S. Fish and Wildlife Service supporting the implementation of the strategy and outlining streamlined processes to assist in conducting consultations; development of partnerships and agreements with state and local water agencies aimed at regulating diversions and releases of water in a manner which addresses the needs of listed endangered species; added research studies on several listed T&E species; utilization of the Watershed Assessment process to identify problem areas and develop projects to help rehabilitate and maintain stability of the more sensitive riparian sites; and the implementation of corrective actions to help minimize the effects of Forest uses on riparian areas occupied by listed threatened or endangered species.
In addition, the Los Padres Riparian Conservation Strategy was recently used as the model for development of a "province wide" set of guidelines to help facilitate the revision of Forest Plan direction on all four southern California National Forests.
The results of monitoring over the past six years has indicated a general trend of stabilization or improvement of riparian habitats and some apparent increases in localized populations of listed species.

Concurrent Session IV. Grassland and Woodland Habitats

Pinyon-juniper woodland trends: interactions of thresholds, landscape heterogeneity and fire
Robin J. Tausch
USDA Forest Service, Rocky Mountain Research Station, Reno, Nevada 89512

Woodlands of singleleaf pinyon (Pinus monophylla), California juniper (Juniperus californica), or occasionally Utah juniper (J. osteosperma) or western juniper (J. occidentalis) are locally important in southern California Pinyon-juniper woodlands in the west have substantially changed historically, driven by two factors involving thresholds for change. First is a woodland expansion and thickening, and second is the introduction of exotic annuals, primarily grasses. Together these changes have driven an increase in fire size, intensity, and frequency, and have dramatically changed successional patterns following fire. Similar changes are occurring in the woodlands of southern California. The affects of more recent fires, such as the 1999 Willow Fire on the San Bernardino Mountains, appear to be headed for the same eventual outcomes that have been observed elsewhere. Size and intensity of fires appears to be increasing, facilitated by both higher levels of woody fuels and the increased abundance of annual grasses. With the presence of shrubs that sprout, or that have seeds with fire enhanced germination, perennial reestablishment following fire is currently occurring. What remains unknown is the abundance of introduced annual grasses that will also follow. With the ability of these grasses to provide high levels of fine fuels, and to provide them in areas that otherwise might not have them, the potential for an increased fire frequency and area is present. The high level of recreational use in most areas of southern California woodlands also increases the chances for ignition. This combination could result in woodlands being lost faster than they can reestablish.

Effects of grazing in oak woodland habitats
Barbara Allen-Diaz
Department of Environmental Science, Policy, and Management – Ecosystem Sciences Division, University of California, Berkeley

Grazing animals interact with plants, animals, sites, and ecosystem processes to produce unique successional patterns across the landscape. Effects of livestock grazing in oak woodland habitats vary across spatial and temporal scales and are considered neutral, damaging, or positive depending on conservation and management goals for different species and communities. Effects on ecosystem species, communities, and processes depend on management strategies controlling kinds, number, distribution and season of grazing animals. Effects of livestock grazing are documented from experimental studies, or suggested from case studies, observation, or general knowledge of expected requirements for water quality, wildlife habitat, biodiversity, or ecosystem functioning. The management link between livestock grazing and ecosystem response in the oak woodland is through residual dry matter. Residual dry matter (RDM) is the dead, herbaceous, aboveground biomass remaining on a site in the fall. RDM is important because of its relationship to nutrient cycles, prevention of soil erosion, and influence on species composition, productivity, and forage quality the following year. Currently, minimum RDM standards are used to manage livestock and protect a variety of resource values. Recent evidence indicates however, that maximum RDM standards may have to be applied to meet habitat requirements for species at local scales, such as burrowing owls, or much broader scales, such as kit fox. A fruitful exercise is to continue to examine the use of livestock grazing as a tool for manipulating vegetation to achieve desired conservation objectives. Grazing management should be assessed in terms of its potential to accomplish conservation goals rather than its potential to simulate or re-create natural conditions. Managers cannot afford to loose this conservation tool, as other tools such as prescribed fire, hand mowing, or re-introduction of large native herbivores are increasingly difficult to apply for many reasons.

Vernal pool community dynamics and management considerations
Marie A. Simovich
University of San Diego, San Diego CA 92110, simo@acusd.edu

California supports a diverse array of vernal pool types. While these pools differ in their physical/chemical attributes, all are patchily distributed in space, discontinuous in time and rapidly disappearing. The floral and faunal communities which inhabit the pools are diverse, highly endemic, extremely dynamic and becoming endangered. Recent work on the crustacean communities has shown differences in richness and species composition between pool types, between pools within a type and within individual pools between years. At least part of this variation is attributable to differing physiological tolerances and life history among species as well as restricted gene flow. Consideration of the interactions between physical/chemical pool attributes and species requirements will be necessary for successful management decisions regarding recovery, preservation, restoration and habitat creation.

Management considerations for burrowing owl populations in southern California
Clark S. Winchell
Carlsbad Fish and Wildlife Office, U.S. Fish & Wildlife Service, 2730 Loker Avenue West, Carlsbad, CA, 92008, clark_winchell@fws.gov

Managing burrowing owls Athene cunicularia for long term population viability means managing the community to which they belong. Specifically in southern California, land managers should maintain the symbiotic relationship between burrowing owls and California ground squirrels Spermophilus beecheyi. Nest site fidelity and burrow usage will be described, and ways to differentiate burrows used by owls from those used by squirrels will be discussed, illustrating to land managers which burrows should be given priority for protection. Burrowing owls use a complex of burrows during the breeding season. Protection of nesting burrows by instituting a burrow marking program is the best way to maintain a colony of owls in areas with multiple land uses. Establishing owl colonies should be done by recreating these burrow complexes, minimally comprising five burrows, and maintaining the colonial structure of the owls by providing sufficient habitat for a number of owls. Placement of artificial burrows should take into account burrow complexes and home range dynamics. Several examples of management programs will be reviewed, discussing such topics as natural history, population dynamics, home range and factors for consideration when establishing or expanding owl populations.

Exotic animals in grassland and oak woodland habitats of cismontaine southern California
Reginald H. Barrett
Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720-3110, rbarrett@nature.berkeley.edu

Over 30 species of terrestrial vertebrates have probably become established in southern California as a result of introductions by humans. Some, like the leopard frog, have extended their range within the state. Others, like the turkey, have been introduced from elsewhere in North America, while most are native to other continents. Some descend from domestic stock that have become feral. I review the history and status of each of these species. Most exotic animals have had little impact on native ecosystems as yet. However, others, like the wild pig, can cause considerable disruption to native communities. I briefly review some of the control programs for these species. Research is needed to adequately determine the status of most introduced animals in California.

Avian population dynamics along elevational gradients in southern California
Mark D. Reynolds
San Diego State University Field Stations, San Diego CA 92182, mreynold@sciences.sdsu.edu

Montane habitats on southern California mountaintops provide critical breeding, migratory and wintering habitat for a diverse community of birds. These mountaintops comprise an archipelago of habitat islands with species diversity and population dynamics on specific mountains related to montane habitat area, distance from other mountaintops and distance from population source areas in the Sierra Nevada. The relationship of adjacent lower elevation habitats and ecotones, including scrub, grassland, oak woodland, oak savannah and riparian areas, to population dynamics in montane habitats (and vice versa), is an import new area of investigation. Recent work suggests that selection along elevational gradients and ecotones plays an important role in genetic diversity and demography of vertebrate populations. Pilot investigations using point count censuses and mark-recapture techniques in the Los Padres National Forest suggest that riparian areas may provide important linkages for bird populations between lowland, transitional and montane habitats.

Fire and exotics species control: a community based approach
Robin Wills
The Nature Conservancy of California, Red Bluff CA 96080

Fire use in grassland and oak woodland communities has developed into a complex issue for California land managers. The historic role and pattern of fire in these vegetation types remains unclear. In addition, alterations to the contemporary landscapes may cause significant variation in post-fire community structure and composition. A lack of measurable goals, as well as a limited spatial and temporal context has further confused the application of fire. Still, appropriately prescribed fire events have proven effective at controlling a number of invasive weed species. The same fire events may often elicit positive change from guilds of native plant species.
Though the effects of fire has been described for individual species and some functional guilds, our understanding of community levels effects are not well defined. The effective use of prescribed fire, as a weed control tool, requires careful consideration of the phenology of all target elements. Negative impacts, from weed control prescriptions, may be mitigated through the planning of long-term fire regimes. Fire planning models, while targeted at weed control objectives, must also capture the spatial and temporal variability necessary to meet the life history needs of a large assemblage of native species.

General Session: Monitoring

The concept of ecological integrity – its relevance to the conservation of biological diversity
Barry Noon
Colorado State University, Fort Collins CO 80523, brnoon@cnr.colostate.edu

Because of the unprecedented rate of conversion of ecological systems, and the accompanying loss of biological diversity, environmental scientists have sought a metric to characterize the desired state of ecological systems. Such a metric would allow managers to assess the efficacy of their management practices in moving ecological systems towards, or maintaining the system within the bounds of, the desired conditions. The concept of ecological integrity has been put forth by the scientific community as an appropriate metric, and measurable definitions have been provided.
According to the dictionary, "integrity" is "the state of being unimpaired, sound," "the quality or condition of being whole or complete." A variety of definitions of ecological integrity exist, most differing in the scale of assessment. A fine-scale approach stresses the structural and compositional aspects of ecological systems focusing on individual species and their dynamics within specific ecosystems. A more coarse-scale approach focuses on macro-scale processes (i.e., primary productivity, nutrient cycling, hydrological regimes), and pays considerably less attention to the structure and composition of the systems from which these processes emerge. Given the uncertainty that surrounds the functional role of individual species, I believe the most responsible course of action at this time is to strive to manage the land so as to maintain ecological integrity at the fine scale.
Recently, a committee of scientists appointed by Secretary of Agriculture Daniel Glickman, has addressed the issue of ecological integrity on public lands. They adopted the following characterization of a system expressing ecological integrity: it is an ecological system that has "the capability of supporting and maintaining an integrated, adaptive community of organisms having species composition, functional organization, and resilience comparable to that of natural habitats of the region." The complexity of this concept is obvious and it is clear that ecological integrity cannot be assessed through a single indicator. In contrast, it will require a set of indicators measured at different spatial, temporal, and hierarchial levels of ecological systems.
I will discuss the concept of integrity, provide an example of its implementation as a management goal on public lands in the Pacific Northwest, and consider its relevance to the conservation of biological diversity.

An ecosystem monitoring strategy for national forests in the Sierra Nevada
Patricia N. Manley
Pacific Southwest Region, US Forest Service, South Lake Tahoe CA 96150, pmanley/r5_ltbmu@fs.fed.us

The Pacific Southwest Region of the Forest Service is engaged in an effort to development consistent management direction across all 11 National Forests in the Sierra Nevada to address resource conditions of greatest concern. Resource conditions being addressed include old-growth forests and associated species, lower westside hardwood forests and associated species, aquatic-riparian-meadow ecosystems, fire management, and noxious weeds. A 20 person team of managers and scientists has been working for over 2 years on the development of a monitoring strategy intended to generate vital information about the status and change of these resources and the effectiveness of future management in achieving desired conditions. The key features of the monitoring strategy are as follows: a conceptual model of ecosystem processes serves as the foundation of the strategy, humans are considered a part of the ecosystem, a breadth of types of information is pursued (i.e., implementation, status and change, and cause and effect monitoring), explicit monitoring questions are identified, candidate attributes of system conditions are derived directly from the conceptual model of ecosystems processes, and unique approaches are being employed to evaluate the efficacy of candidate attributes and sampling designs.

Integrating monitoring into adaptive management: challenges, limitations, and an agenda for the future
Barbara E. Kus
U.S. Geological Survey, Western Ecological Research Center, Department of Biology, San Diego State University, San Diego, CA 92182, bkus@sunstroke.sdsu.edu

Monitoring is an essential component of adaptive management, a process that iteratively evaluates and refines management practices with regard to their efficacy in achieving desired conditions. However, only a fraction of the large volume of monitoring data collected within the context of natural resource management, particularly that involving endangered species, is being applied in this manner. Hindering this process are constraints ranging from the way data are collected, reported, and stored to the lack of coordinated and standardized approaches across management entities. Using examples from birds, I address the elements of monitoring studies critical to their usefulness in an adaptive framework, including the need for a clearly stated purpose linking the monitoring to specific management actions, the need for appropriate design and methodology, and the need for standardization within and among studies. I then identify other obstacles limiting the use of monitoring data in management, such as the need for centralized, funded, and staffed data retrieval systems, a process for synthesis and analysis of monitoring data, and a formalized system for coordinating efforts across agencies and others engaged in monitoring. I close by suggesting some mechanisms by which this coordination can be achieved.

Monitoring for biodiversity: limitations of sampling theory
Douglas H. Deutschman
Department of Biology, San Diego State University, San Diego CA 92182, doug@sciences.sdsu.edu

The success of any monitoring program will depend on the accuracy and precision of the population estimates. In statistics, sampling theory provides a conceptual framework in which to optimize the sampling process. Classical sampling provides three key approaches to survey design: random, stratified, and cluster sampling. In all three designs, population parameters can be estimated easily from sample data. As importantly, the uncertainty around the estimators can be assessed. Often, these traditional approaches are inadequate for estimating the size of biological populations due to habitat heterogeneity, clustered distributions, temporal autocorrelation, and the paucity of a priori information. Adaptive sampling is an emerging methodology that may be of use in monitoring programs. In adaptive sampling, the selection of samples is a sequential process that is modified by the value of each sample as it is collected. This process may provide improved reliability and efficiency but may also be more vulnerable to bias. These ideas are illustrated by analyzing the results of a 17-year monitoring program tracking the density of Bowhead Whales in the Alaskan Beaufort Sea. The sample design is a traditional stratified random sample with strata defined by sections of the Beaufort Sea. The accuracy of the monitoring program is limited both by the uneven implementation of the sampling protocol and the behavior of the whales. In choosing among sampling methods it is important to explicitly consider the potential bias, robustness, efficiency, and ease of implementation of each approach.

Concurrent Session V. Regional Issues

Structure of soil organisms and ecosystem processes in southern California: dealing with complexity in a changing environment
Michael F. Allen*, Kathleen Treseder, Cara Hinkson, and Louise Egerton-Warburton
Center for Conservation Biology, University of California, Riverside, Riverside, CA 92521-0334
* michael.allen@ucr.edu

Southern California ecosystems are rapidly being altered by human activities at both the regional and global level. Soil organisms are essential elements in ecosystems because they process C and nutrients, and provide those limiting resources to plants. They also provide the glue that holds soil particles together and the base for many food webs. Increasing atmospheric CO2 places greater nutrient stress on plants. This pushes increasing fungal and mycorrhizal activity and increases elemental cycling rates. Increasing N deposition associated largely with automobile pollution alters competitive relationships among plants as well as facilitating bacterial activity and reducing mycorrhizal diversity. These two perturbations, push ecosystems in polar directions for C and N dynamics but both increase rates of elemental throughflow. These changes influence both the composition of microbes in soil and the resulting soil food webs, and influence neighboring regions and pollutant levels in waters. The implications of these flows will be magnified up to aboveground trophic levels to T&E species in as of yet unknown directions. Predicting the directions and magnitudes of change is an essential step in developing sustainable management plans.

If caterpillars sing, do butterflies cry? (Subtitled: retrospective and prospective patterns of butterfly biodiversity across urbanized coastal southern California)
Rudi Mattoni
Lepidoptera Research Foundation, Inc., Beverly Hills, CA, mattoni@ucla.edu

About 122 "species" of butterflies occur across urbanized cismontane southern California - defined as the plains and watersheds extending from Ventura to San Diego below 2500 feet elevation. Only one species is extinct, with three listed as endangered. In order to present a coherent overview of present and future biodiversity among butterflies of the region, I partition all species into categories based on relevant autecological and demographic characteristics that convey conservation significance. As an example, there are 23 species which I refer to as "garden species, " that occur throughout most of the year across all habitats from wilderness to downtown windowboxes and can be expected to persist indefinitely as human mascots. Garden species are all characterized as highly dispersive, multiple brooded, and using an array of foodplants. The remaining 98 extant non-garden species are organized into 10 classes based on their rarity and natural history. A complete catalog of species, with defining characteristics and a consensus conservation evaluation, will accompany this paper as an appendix. The paper invites discussion on how and whether to monitor some small number of species that may be useful as indicators and/or umbrella species.

Status, conservation issues, and research needs for bats in the south coast bioregion
Karen L. Miner 1 and Drew C. Stokes 2
1 California State Parks, San Diego, CA 92108, minerkl@aol.com
2 U.S. Geological Survey, Western Ecological Research Center, San Diego, CA 92182, dstokes11@aol.com

California’s bat fauna is one of the most diverse in the United States. Of the 23 species of bats in the state, the distributions of 21 include the South Coast Bioregion. Though none are officially listed as threatened or endangered at this time, many species appear to have experienced population declines and 13 are considered sensitive by wildlife regulatory agencies. Because winters are relatively mild, lower elevations in the South Coast Bioregion may provide important wintering habitat for some migratory species. The major conservation issues include a limited understanding of bat distribution, status and seasonal habitat associations within the region. Because of this, none of the currently approved habitat conservation plans in the region include bats. This is unfortunate, because the juxtaposition of roosting habitat to foraging habitat and water sources is important to the maintenance of bat populations at the landscape level. Other potential threats to bats in the region include loss of riparian and oak woodland habitat, various types of water-related projects, tree management, renewed mining, spelunking, rock-climbing, pesticide use, highway projects and bridge replacement, vandalism, and public health and safety issues, including direct extermination and mine closures. Research needs include the collection of information on general status and distribution for all bat species, seasonal use patterns, characterization of suitable geologic roosting habitat, foraging habitat preferences, landscape use patterns and effects of urban/suburban expansion, and impacts from insect control efforts and from recreational activities such as rock-climbing. Region-specific issues for particular species of bats will be discussed.

Carnivore conservation in southern California: ongoing research of the effects of habitat fragmentation and landscape connectivity on predator populations
Kevin R. Crooks 1, Chris Haas 2, and Lisa Lyren 2
1 Department of Biology, University of California, San Diego, CA 92093-0116, krcrooks@earthlink.net
2 Department of Biology, California State Polytechnic University, Pomona CA 91768

In the context of carnivore conservation in southern California, we highlight several research programs in the region that are assessing the effects of habitat fragmentation and landscape connectivity on predator populations: 1.) A project in San Diego urban habitat fragments that investigated the effects of landscape and local fragmentation on carnivore populations and evaluated the top-down role of coyotes in this system. 2.) A project investigating the use of corridors and roadway underpasses by a suite of mammalian carnivores in the Puente-Chino Hills, 3.) A radio-telemetry study on the movement patterns and underpass use of bobcats and coyotes along State Route 71, and 4.) A regional assessment of the degree of landscape-level connectivity in coastal southern California. We conclude by summarizing the status of carnivore research in southern California and providing recommendations for future research.

Carnivore conservation in southern California: early lessons from ongoing telemetry research in the Santa Monica Mountains and Simi Hills
Raymond M. Sauvajot 1*, Denise Kamradt 1, Seth P. Riley 1, Eric C. York 1, Robert K. Wayne 2, and Todd K. Fuller 3
1 U.S. National Park Service, Thousand Oaks, CA 91360, * ray_sauvajot@nps.gov
2 Department of Biology, University of California, Los Angeles, CA 90095
3 Department of Natural Resources Conservation, University of Massachusetts, Amherst, MA 01003

Habitat loss and fragmentation threaten the survival of many wildlife species, particularly carnivores that utilize large home ranges and exist at low densities. In 1996, we initiated a radio telemetry study of bobcats, coyotes, and gray foxes in the Santa Monica Mountains and Simi Hills, a mosaic of core habitat interspersed within a matrix of open space and human land uses. We have monitored over 150 radio-collared bobcats, coyotes, and gray foxes to examine distribution, movement, and survivorship in relation to land use, habitat, and human activity data. We present results of these species’ habitat usage, home range characteristics, and survivorship within this urban/wildland interface area. Interspecific comparisons are presented as well as differences between urban-inclined and core habitat-inclined animals. Additional analyses assessing habitat preferences––particularly with respect to human land uses––are also presented. Implications of our results and ongoing research activities are discussed in the context of carnivore conservation across fragmented landscapes of southern California.

Recreation impacts to habitat
Melanie Beck
National Park Service, Santa Monica Mountains National Recreation Area, melanie_beck@nps.gov

Santa Monica Mountains National Recreation Area encompasses approximately 150,000 acres of both private and public lands adjacent to the Los Angeles region. One in every 17 Americans lives within an hour’s drive of the mountains, hence, the mountains are a popular outdoor recreation destination. Recreation impacts in the Santa Monica Mountains stem mainly from use of the region’s 700 miles of trails. Trails fragment habitat and create "edge effects" typical at the interface of human presence and undisturbed native habitat. Edge areas exhibit reduced biodiversity. Edge effects include the retreat of shy species from the trail corridor; disturbance of roosting, nesting and other survival-related activities owing to flushing and fleeing reactions; non-native plant introduction from changes in light regime and seeds carried in on clothing and pack animals; and impacts to aquatic species from trail erosion. Studies of recreation trail impacts to wildlife are not abundant. Staff at Santa Monica Mountains National Recreation Area are currently studying large carnivore movements and compiling a sensitive animal species database. Maintenance crews perform corrective procedures to reduce erosion from trails, such as gradually reducing steep grades and out-sloping trails to reduce water runoff speed. In the absence of research findings, a conservative approach to habitat protection would include: reducing the number of trails to reduce human dispersal into natural habitat, limiting trail use seasonally; not allowing dogs on trails, and constructing trails correctly. Finally, instilling an environmental stewardship ethic in the public through education is crucial for long-term biodiversity protection.

What southern California growth means to biodiversity
Tom Scott*, Jim Sullivan, and Nanette Pratini
Department of Earth Sciences, University of California, Riverside, Riverside, CA 92521, *tomscott@citrus.ucr.edu

Descriptions of southern California’s growth inevitably plunge into numbing superlatives and exponential curves. Population forecasts for the region are overwhelming, foreboding extinctions and ecosystem demise. Every ecologist knows that these events are coming, but we have not attempted to strategically link the patterns of growth to specific changes in the region’s biodiversity. To date, southern California losses of biodiversity have been chaotic, because land consumption is based on past and current patterns of development rather than spatially optimal growth. Nevertheless, the study of land conversion provides the best mechanism for bringing forecasts of human growth down to the scale of ecological and evolutionary processes. The best unit for the study of land conversion has been the single-family house; the location, extent, and timing of housing construction has been driven (and constrained) by: (1) market demand for houses, (2) the perceived return on investment, and (3) the constraints on each individual parcel of land. Market demand sets the potential build-out of a parcel, from high-density suburbs to rural ranchettes – with differential impacts to biodiversity. Market demand can be divided into the need for: (1) more homes to match population growth, and (2) better homes to match the accumulation of wealth and the desire for a higher quality of life. Investment fuels housing booms, as shown by construction in the late 1980’s. Investors can also abandon land develop when better profits are available elsewhere. Constraints on the develop of each parcel are related to the market but include its jurisdiction (city are more strict than counties), adjacent uses, the size of the parcel, its topography, and most recently its endangered species. The next lands slated for development are always predictable, but their rate of development is cyclic and variable. The long-term projections of land conversion are tenuous, however, the primary governors have been distance to jobs centers (proximity to freeways) and affordability. The concept of amenity value has produced an odd conundrum for conservation: new, affluent home buyers are creating a demand for rural housing which challenges species persistence and at the same creates a political basis for species conservation and preserves.

Concurrent Session VI. Estuary, Beach and Strand Habitats

Lagoon ecology of central coast steelhead and tidewater goby
Jerry J. Smith
Department of Biological Sciences, San Jose State University, San Jose, CA 95192

Late spring and summer beach development builds a sandbar across most central California stream mouths, producing summer lagoons. In wetter years the extensive loss of beach sand results in later development of the bar, and in some wet years high summer inflows result in periodic over-topping and breaching of the sandbars. In drier years sandbar formation is usually earlier, but may be delayed because of scarcity of tidal sand. Inflows after sandbar formation raise lagoon levels and greatly increase lagoon size and habitat variety. Inflows also convert the lagoon towards fresh water, with the surface freshwater layer thickening and the bottom saltwater layer percolating through the bar. Lagoons fully converted to fresh water are generally cool, well-mixed, and suitable for steelhead rearing. Brackish lagoons, with insufficient inflows after sandbar formation, remain stratified unless mixed by strong winds; water temperatures are high and dissolved oxygen levels often low in the bottom saltwater layer, producing poor rearing conditions for steelhead. Tidewater gobies tolerate a wide range of salinity (1-30+ ppt) and water quality conditions, but generally require sandbar closure to produce the calm lagoon conditions that promote their summer population explosions. Tidewater gobies also depend upon calm backwaters as refuges against storm flows and/or draining of small lagoons when the sandbar is opened in winter. Other fresh and saltwater fishes can heavily use lagoons, depending upon salinity conditions.

Up, down or stable – what do we know about populations of beach and estuarine endangered birds?
Abby N. Powell
U.S. Geological Survey, Northern Prairie Wildlife Research Center, Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, anpowell@comp.uark.edu

The coastal beach-dune ecosystem in California supports two threatened/endangered species, California least tern (Sterna antillarum browni) and western snowy plover (Charadrius alexandrius nivosus). The beach ecosystem is highly stressed as a result of shoreline development, invasion of exotic plants, beach stabilization, and heavy recreational use. Least tern populations have increased significantly since the 1980s. Snowy plover populations, however, show continued decline along California’s coast. Management practices to protect least tern nesting colonies appear to be successful for tern but do not offer a protective umbrella for plovers. More research is needed to monitor reproductive success and survival of snowy plovers in order to improve management practices and preservation of nesting areas. Impacts to estuarine ecosystems have been severe and include loss, degradation, and fragmentation. The imperiled species within this system is the endangered light-footed clapper rail (Rallus longirostrus levipes). Rail populations have ranged from a low of 142 pairs in 1985 to a high of 307 in 1996 during the nineteen-year period they have been monitored. Most alarming is that only one estuary consistently supports over 50% of California’s rails, and three sites support over 80%. Although Belding’s savannah sparrow (Passerculus sandwichensis beldingi) is not federally listed, its populations appear to be stable or declining but monitoring is erratic at best. Belding’s savannah sparrows are area-sensitive and reproductive success appears to be low in fragmented marshes. Research on productivity and survival of rails and sparrows is needed. Habitat enhancement and creation should be the highest priority for estuarine birds.

Status of small mammals in near coastal habitats, with emphasis on the endangered Pacific pocket mouse
Wayne D. Spencer
Conservation Biology Institute, 815 Madison Ave, San Diego, CA 92116, wdspencer@consbio.org

Habitat loss in southern coastal California has caused local extinctions and contractions in mammalian biodiversity since the early twentieth century, but this decline has been poorly documented. The critically endangered Pacific pocket mouse (PPM; Perognathus longimembris pacificus) offers an interesting study in species decline, and hopefully, future recovery. Considered extinct for over 20 years, the PPM is now documented at 4 tiny sites in Orange and San Diego Counties. Intensive research initiated in 1998 suggests that PPM recovery will likely require active translocations or reintroductions, but existing information on species’ biology and the availability of translocation receiver sites has been insufficient to design a translocation program. Recovery research has therefore focused on a systematic search for translocation receiver sites; laboratory and field experiments using non-listed surrogate subspecies (P. l. longimembris and P. l. bangsi); studies on the historic and extant genetic diversity of PPM; increased monitoring of PPM populations; and experimental habitat manipulations to increase populations. We have identified translocation study sites throughout the PPM’s historic range and are currently ranking potential receiver sites in the field. The surrogate studies helped us design individual marking and monitoring methods for PPM and will be used to test captive breeding protocols and translocation methods. Genetics data will help us select PPM donor populations. We’ve also initiated experimental thinning of coastal sage scrub in hopes of increasing habitat quality and population sizes. Our approach has been to proceed cautiously in designing a translocation program, but we are prepared to act swiftly to prevent extinction.

Hydrologic factors of coastal aquifers that impact biotic integrity
Randy T. Hanson and E. G. Reichard

U.S. Geological Survey, Water Resources Division, Santa Ana Basin NAWQA, 5735 Kearny Villa Rd, San Diego, CA 92123
Coastal watersheds are complex systems of surface-water and ground-water flow. These systems have natural variability that also has been affected by anthropogenic changes. Climate variability is the major natural factor that can affect the supply of recharge, runoff, and streamflow. Human development of water resources in coastal watersheds has resulted in streamflow depletion and ground-water overdraft. In turn, these aspects of development have resulted in seawater intrusion, land subsidence, additional sediment transport, contaminant migration, and vertical flow between aquifer systems. The quantity and quality of water present in ecosystems of coastal watersheds can potentially impact biotic integrity through natural variability and human development.

Assessing salt marsh habitats
Kevin D. Lafferty
U.S. Geological Survey, Ventura, CA 93001-4354, kevin_lafferty@usgs.gov

In Southern California, most salt marsh habitat is gone and what remains is degraded. For this reason, it is often of interest to assess the condition of salt marshes over time such as when determining the success of a restoration project. We may also want to know how a particular salt marsh, or area within a salt marsh, compares with other neighboring areas (to identify impacts or opportunities for restoration). There are several approaches one can use to assess wetlands. I will discuss three approaches that hold promise for future evaluations. I will first argue that most salt marshes can be easily categorized into two functional types, fully tidal and seasonally tidal, based on a simple biotic index (presence of horn snails) that is preserved in sediment cores. Another technique for assessing salt marshes is to use species-area curves. Data for birds and fishes, show a strong species-area relationship. Deviations from that relationship may be associated with wetland quality. Another novel approach is to use parasite communities as broad indicators of ecosystem function. For example, a diverse and abundant trematode community reflects a rich community of free-living species in a marsh because environmental changes can affect larval trematodes at each stage of their complex life cycles. I will present data from a recent study of larval trematodes infecting the Horn Snail, Cerithidea californica, that indicates the success of the Ash Avenue Restoration Project at Carpinteria Salt Marsh in California.

Biodiversity benefits of coastal wetland restoration
Jack Fancher
U.S. Fish & Wildlife Service, Carlsbad Field Office, Carlsbad, CA 92008, jack_fancher@fws.gov

Healthy wetlands are renowned for their biological diversity, being the transition between aquatic and upland habitats. Coastal wetlands within the reach of the sea are more complex when under the daily influence of the tides. The continually but regularly changing water level of ocean tides creates habitat zones and a complex ecosystem. When tidal influence is diminished, this complex ecosystem simplifies. Coastal southern California has an unfortunate history of destroying tidally influenced wetlands by converting them to other uses, such as harbors, marinas, and housing developments. Many of those wetlands that survived this onslaught have been cut off from their tidal influence and become relatively depauperate. Restoration efforts along the Southern California coastline have emphasized restoration of tidal influence to these diminished and damaged wetland ecosystems. Accurate predictions of the tidal regime that would result from restoration are very important to predicting the biological benefits. Large groups of organisms (such as salt marsh plants, marine fish and invertebrates, shorebirds, and fish eating seabirds) have actually been reintroduced into formerly degraded areas by reconstruction of tidal influence. Post- construction biological monitoring confirms the blossoming of biological production and diversity at two restoration project case history locations, Anaheim Bay, Orange County, and Batiquitos Lagoon, San Diego County.

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