CADMAN, D.C. and CUSHMAN, J.H. Sonoma State University; Rohnert Park; CA 94928; laguna@sonic.net
Restoration Ecology in vernal pools: litter accumulation and the composition of plant communities.
             In California grasslands exotic annuals have invaded the insular habitat of vernal pools. We examined the effects of removing accumulated plant litter by raking in vernal pools for two consecutive years. The study plots incorporated the bottom, edge and upland pool zones, with paired removal and control plots for the three zones in each pool. We found species richness changes in relation to pool zone; the bottom and upland are significantly different from each other and the edge contained numbers of species in-between the other regions. Species richness was significantly increased in plots where litter was removed. We analyzed percent cover of all native species and found a significant increase in the treated plots. We also looked at overall percent cover of exotic grasses and found a decrease in raked plots compared to the control plots. We examined several well-represented species, both native and exotic, and found significant percent cover differences in raked plots. Some of these species showed a greater treatment effect in certain pool zones. These results indicate that accumulation of litter in vernal pools and their adjacent uplands causes a reduction of species richness and changes in species composition, including a decrease of native species.

COPPOLILLO, P.B.; Graduate Group in Ecology, Dept of Anthropology; University of California; One Shields Ave.; Davis, CA 95616-8522; pbcoppolillo@ucdavis.edu
Central place models: a tool for analyzing and predicting the impacts of herded cattle (and other resource use systems)
             Most spatial models of grazing assume a global search; that is, the entire paddock or landscape is available to grazers. These "unconstrained" models characterize landscapes based on their own properties without regard for how individual grazers perceive them. In most of East Africa cattle are herded and are forced to start and end each day's grazing at their enclosure. Consequently, the quality of any single patch depends not only on the properties of the patch itself, but also on it's location relative to home and to other resources. Thus, global search is not a realistic assumption. Using data from 73 full-day herd follows among a group of agropastoralists in western Tanzania, I build and test an unconstrained model and compare its performance to a "central place" model that defines the landscape relative to herders' homes (the central place) and dry season water. The central place model provides insights into the grazing system that are not apparent using the unconstrained approach, and it explains more of the variance in grazing intensity. Because many types of resources are collected around a focal point, central place models should have wide applicability for analyzing and modeling at patterns of resource use, particularly in the developing world.

FOX, H.E.; Integrative Biology; UC Berkeley; 3060 VLSB; Berkeley, CA 94720-3140; hfox@socrates.berkeley.edu
Environmental factors influencing recovery of coral reefs damaged by destructive fishing practices
             Coral reefs are among the Earth’s most productive, diverse, and valuable habitats. Reefs in Southeast Asia contain the highest diversity of coral species and a staggering number of reef-dependent organisms. However, pressures from rapid population and economic growth in this region have brought many reef ecosystems to the point of collapse. One of the most devastating threats to reefs comes from dynamite or "blast" fishing, using homemade bombs detonated over the reefs. Blast fishing not only kills organisms within the 1 to 5 meter blast radius, but also pulverizes the coral skeletons themselves, leaving a shifting, unstable rubble field that rarely returns to a healthy reef community. This destructive fishing practice is widespread and occurs in nearly 30 countries in Southeast Asia and Oceania. In this study, coral reef regeneration will be examined at several scales in areas damaged by blast fishing to reveal factors influencing coral recovery rates and successional trends. The study will be conducted in Komodo National Park (KNP), Indonesia, where blast fishing has occurred at varying levels since 1950. This study will focus on the effects of source coral, water flow, and substrate type on coral recruitment. Methods to stabilize the loose substrate will be tested, and subsequent coral recruitment, changes in coral cover, and abundance of other species will be quantified. At both blasted and unblasted sites, we will characterize the habitat and measure variables that might affect coral recovery, including substrate size and movement, hydrodynamic regime, proximity to intact reefs, and elapsed time since disturbance. By correlating these variables and manipulating substrate stability, we intend to determine factors mitigating coral recovery rates and successional trends. By recreating the structural foundation of the reef with stable, rugose substrate, coral recovery may be accelerated. After 3 years, initial patterns of colonization and regeneration should be apparent.
             An integral goal is to develop a relatively inexpensive and effective method for enhancing coral reef rehabilitation; this method could be incorporated in reef management programs throughout the Pacific region. Studying recovery of communities that have been disturbed can lead to much-needed insight into how elements of the complex coral reef ecosystem interact. Furthermore, as human pressures on reefs continue to increase, understanding the ecological responses to perturbation and processes of recovery is crucial in guiding management policy to ensure the preservation of coral reefs for generations to come.

FRENCH, A.R.; Center for Tropical Research; Department of Biology; San Francisco State University; 1600 Holloway Ave.; San Francisco, CA 94132-4202; afrench@sfsu.edu
Interference competition and social structure in a guild of Afro-tropical seed dispersers.
             Seed dispersal by large frugivores such as hornbills and monkeys is a critical process for the maintenance of diversity in tropical forests. Five species of Ceratogymna and Tokus hornbills and four species of Lophocebus and Cercopithecus monkeys in the Bouamir Research Area of the Dja Reserve, Cameroon, disperse fruit from a large percentage of the tree species found in the reserve. Site preferences and movement patterns vary dramatically between each species. Therefore, knowledge of the mechanisms involved in resource use by each species play an important role in understanding overall forest dynamics. While various aspects of resource selection have been well studied, critical variables involved in frugivore foraging remain unclear. From over 3,000 hours of focal tree watches at 25 species of fruiting trees conducted during 1997, foraging preferences and interactions between species were observed. Interference competition is shown to decrease the foraging success of the smaller animal species while simultaneously creating a social hierarchy between individuals and species in the community. This resulting social hierarchy may ultimately affect which tree species are dispersed, thereby affecting forest structure and regeneration in an increasingly fragmented landscape.

GAFFNEY, K.A.; Department of Biology; Sonoma State University; 1801 East Cotati Ave.; Rohnert Park, CA 94928; crp@sonic.net
Influence of an invasive exotic grass on a riparian ecosystem: effects of fire and disturbance
             Alien grasses are known to invade and modify native plant communities and can influence ecosystem processes. The grass-fire cycle plays an important role in successful invasion. I performed a comparative study in the riparian zone of the Russian River which evaluated the impacts of Arundo donax on perennial species diversity and density of various species according to disturbance level. Invaded and uninvaded sites were compared, as were invaded burned sites and invaded unburned sites. My data indicate that there is a significant reduction in perennial species diversity at those invaded sites which are not subjected to regular flood flows, that density of Arundo is greatest in intermediately disturbed areas, and lowest in the highly disturbed active channel areas. Floodplain areas that burned after invasion by Arundo were characterized by significantly lower perennial species diversity, significantly higher Arundo densities, with woody native perennials removed by the fire. These data indicate that Arundo donax is a successful invader in the Russian River riparian zone, capable of modifying the native ecosystem, affecting succession, and decreasing biological diversity.

GIUSTI, G.; Forest Advisor; UC Cooperative Extension-Mendocino/Lake Counties; Ag. Ctr./ Courthouse; Ukiah, Ca., 95482; gagiusti@ucdavis.edu
Applied conservation biology in today's world: the coho challenge
             Coho salmon have precipitously declined throughout their biological range since 1970. A number of biological and physical factors have been cited as the cause of the decline and are recognized as barriers to their recovery. Sustained recovery of the species is dependent on a number of strategies that will: improve habitat conditions, address physical barriers that are inhibiting recovery, and increase social awareness of the current condition of the resource. In order to address the magnitude of the decline and reverse current population trends, significant changes must occur in institutional and financial approaches that are currently affecting land management policies and practices. These fundamental changes must recognize, and support: the importance of directed educational programs involving stakeholder groups, changes in capital lending procedures recognized as limiting landowner options, and the need to involve all levels of local, State and Federal decision makers. This paper presents a case study currently developing in Mendocino County, California that may provide a model for conserving biological resources which addresses financial, biological and social aspects necessary to improve salmonid recovery. This paper presents a conceptual model necessary to involve and improve awareness of stakeholder groups and presents an unprecedented example of a land acquisition strategy currently being developed by the Redwood Forest Foundation, Inc. utilizing tax-exempt, municipal bonds as a means of minimizing investor expectations while engaging communities in land management strategies.

GOLDSTEIN, B.E.; Department of City and Regional Planning; University of California, Berkeley; brugo@uclink4.berkeley.edu
A new species of regulatory science: multi-stakeholder consensus processes and the negotiation of habitat conservation plans
             I am examining how science is used by multistakeholder consensus-based committees in the implementation of the Federal Endangered Species Act’s Habitat Conservation Plans (HCPs) provisions. HCPs allow private landholders to kill endangered species or eliminate a portion of their habitat in exchange for money and land that compensate for the loss. Many leading conservation biologists have questioned the scientific rigor of HCPs. Despite this lack of scientific credibility, HCPs have largely resisted vigorous efforts to destabilize them through policy advocacy and peer review. Nonetheless, some HCP organizers are starting to play it safe and incorporate peer-reviewed conservation biologists in plan preparation in an advisory capacity. My study of HCPs has two parts. First, I am trying to understand how consultants and stakeholders arrived at the scientific claims that were criticized by conservation biologists. I am focusing on the social, political, and institutional factors that conditioned the scientific claims that are made in HCPs. Second, I am closely examining HCPs that involve conservation biologists in the preparation of the documents rather than bringing them in for retrospective ‘peer-review’. I am paying particular attention to whether these arrangements precipitate a change in the scientific judgement of peer-review conservation biologists, consultants who practice ‘regulatory science,’, and the stakeholders who embrace a diversity of scientific and non-scientific practices and beliefs. I am particularly interested in hearing from this audience how to make my study more applicable and accessible to conservation biologists.

GRECO, S.E.; Center for Integrated Watershed Science and Management; John Muir Institute of the Environment ; University of California ; 1 Shields Ave.; Davis, California; segreco@ucdavis.edu
Monitoring riparian landscape evolution and the development of critical habitat of the yellow-billed cuckoo (Coccyzus americanus occidentalis) on the Sacramento River, California, miles 197-220.
             There are few suitable riparian forests remaining in the Sacramento Valley capable of supporting populations of the western subspecies of the yellow-billed cuckoo (Coccyzus americanus occidentalis), a California State-listed endangered species. The cuckoo is a neotropical migrant species that winters in South America and once bred abundantly in summer throughout the western Pacific states, however, today their northern range is limited to the middle reaches of the Sacramento River. The decline of the cuckoo is mainly attributed to riparian habitat losses from agricultural development and may have been enhanced by the widespread application of pesticides. Past field studies have shown that the western yellow-billed cuckoo is a riparian-obligate forest-interior species that is generally found associated with large blocks (>41 ha) of riparian vegetation consisting of willow (Salix spp.) and cottonwood (Populus fremontii) forests in combination with open water, such as oxbow lakes or backwater channels. Analyses of historical riparian forest and woodland distribution patterns once present in the Central Valley compared to more current conditions suggest that approximately 98.5 percent of intact riparian forest and woodland has been lost. In a selected study reach (miles 197-220) of the Sacramento River, a major alluvial meandering system, vegetation type and size structure were mapped using 1997 aerial photography with areas known to contain core habitats used consistently by cuckoos over the past two decades. The vegetation mapping methodology was field verified in 1997 and a habitat model was field tested in 1998. The same mapping methodology was applied to several historical aerial photographic sets of the study reach to monitor the dynamic fluvial geomorphic and vegetation structural development of the critical habitat areas. This spatial information was then entered into a geographical information system for landscape analysis. Findings include that the study reach was highly dynamic until the mid-1970s when channel revetment was installed; and the highest observed occurrence of yellow-billed cuckoos corresponds to an area containing an abandoned 1938 channel adjacent to vegetation that was established in the 1960s and 1970s. An implication of this research for restoration projects designed to mitigate for yellow-billed cuckoo habitat and recovery on the Sacramento River is that they should focus on maintenance of channel hydrodynamic processes that give rise to complex landscape structures. This study shows that if natural channel processes, such as channel migration and channel cut-off, are permitted to operate then critical habitats can develop in less than fifteen years.

GROSSINGER, R.M.; San Francisco Estuary Institute; 1325 South 46th Street; Richmond, CA 94804; robin@sfei.org
Historical ecology research: an example from the San Francisco Estuary, California.
             Through a broad-based regional effort to identify historical data, extensive information about the San Francisco Bay Area landscape near the time of European contact was discovered. Over 1000 independent sources of historical data were integrated to form a GIS of the "Native Landscape" (circa ~1800). A corresponding set of coverages of the "Modern Landscape" (ca. 1998) was developed based upon modern aerial photography. The GIS catalogues wetlands and related habitats over an x square mile area to a resolution of 0.1 acres during the period 1770-1860 and 1997 and is currently extending into additional habitat types and time periods. Methodologies were developed to assess and record the certainty associated with each mapped feature. The resulting Bay Area EcoAtlas provides detailed spatial and temporal information for ecological planning in the region. An intensive, well-documented historical Reconstruction can reveal new information about how the region was organized prior to European land-uses (e.g. landscape ecological parameters such as habitat patch size, configuration, connectivity), the processes responsible for the observed organization (i.e., the relationship of habitat distribution to local climate, topography, and native land use), and the ecological functions of the landscape (support of native species and human needs).

HELLMANN, J.J.; Center for Conservation Biology and Department of Biological Sciences; Stanford University; Stanford, CA 94305-5020; jessicah@leland.Stanford.EDU
Predicting the effects of regional climate change: a model of dynamic resource use in a threatened butterfly
             Butterflies are well suited for study on the influence of climate change in biological communities. This suitability stems from the sensitivity of butterflies to the thermal environment, their often large population fluctuations, and their habitat and resource (i.e., host plant) specificity. Butterfly host plant use is determined by the availability and quality of host species and by evolved host plant preferences; these factors are directly or indirectly driven by climate and weather. Therefore, regional climate change is likely to affect butterfly populations via impacts on their resource base.
             I report a model that illustrates how elevated temperature may impact the viability of a population of the threatened butterfly, Euphydryas editha bayensis. This model simulates change by affecting the availability of the butterfly’s host plants. The interaction between E. e. bayensis and two species of annual serpentine grassland plants is driven by the temporal overlap in availability of food resources and larval development. Human influences on the climate are expected to alter the timing of this feeding relationship which may impact the relative use of the two host species and ultimately affect the likelihood of butterfly population persistence. Built with supporting field observation and experimentation, this model explores the relationship between host plant availability and larval survivorship under scenarios of regional climate warming and makes specific predictions of how change in E. e. bayensis population size arises from accelerated host plant senescence under altered regional temperature.

HOLBROOK, K.M.; Center for Tropical Research; Department of Biology; San Francisco State University; 1600 Holloway Avenue; San Francisco, CA 94132; holbrook@sfsu.edu
Seed dispersal and implications of long distance movements of Ceratogymna hornbills in Cameroon.
             Research in the Dja Reserve in southern Cameroon indicates that Ceratogymna hornbills disperse the seeds of more than 22% of the major tree species and may demonstrate up to 5-fold changes in abundance in response to fruiting. To investigate the role of hornbills in rainforest conservation and structure the seasonal movements of C. atrata and C. cylindricus were studied using radio telemetry. Fifteen individuals were captured, radio-tagged, and tracked from December 1995 through December 1996. To determine maximum seed dispersal distance seed passage trials were also conducted on captive individuals using a variety of fruits common in hornbill diet. Passage rates ranged from 64 - 765 minutes. Results suggest hornbills have the potential to disperse seeds over large distances and may make movements in excess of 290 km. The implications of long distance movements are discussed in relationship to conservation and reserve design.

HOLL, K.D.; *Fox, Laurel R., and Fusari, Margaret H.; Department of Environmental Studies; *Department of Biology; University of California; Santa Cruz, CA 95064; kholl@cats.ucsc.edu
Restoration of maritime chaparral habitat at the former Fort Ord Army base
             The goal of this research is to design strategies for managing and restoring maritime chaparral, with particular reference to areas of capped landfills. The two main components of the research are: (1) to investigate biotic and abiotic factors affecting establishment and survival of two rare annual plant species, Gilia tenuiflora ssp. arenaria (sand gilia) and Chorizanthe pungens var. pungens (Monterey spineflower); and (2) to determine whether it is feasible biologically and legislatively (given concerns about woody roots penetrating flexible membrane liner caps) to restore chaparral shrubs on landfills with a flexible membrane liner. We planted both species of rare annuals and ten species of chaparral shrubs at the former Fort Ord Army base in Monterey County in the growing seasons of both 1996-7 and 1997-8. For the two species of rare annuals we manipulated a number of variables, including: (1) large animal herbivory, (2) nutrient levels (C. pungens var. pungens only), and (3) density and composition of background vegetation (both a commonly used non-native erosion control mix and a native plant mix were seeded). We planted seedlings of chaparral shrubs on a simulated landfill cap with a flexible membrane liner and on a control area. The two annual herbs had high survival rates after transplanting. Survival and reproductive output of these annual species was limited by: (1) herbivory, (2) low soil nutrients, (3) high soil moisture, and (4) competition with background vegetation regardless of its composition. Chaparral shrubs showed high survival but low growth rates; growth rates were similar on the simulated landfill cap and the control area. After two years only Lupinus arboreus had a well developed root system that reached and ran parallel to, but did not penetrate, the flexible membrane liner. We will monitor survival and growth of both annual and shrub species over the next few years in order to develop long-term management recommendations for restoration of maritime chaparral communities.

HUGHES, J.B., DAILY, G.C., EHRLICH, P.R. and RICKETTS, T.H.; Center for Conservation Biology; Dept. of Biological Sciences; Stanford University; Stanford, CA 94305; jhughes@leland.Stanford.EDU
The use of an agricultural countryside by native biodiversity
             The pressure of agricultural expansion has driven much of the destruction of forests around the globe and consequently is responsible for the extinction of thousands of species and populations every year. Ecologists traditionally have considered agricultural habitats to be ecological "deserts" – areas where almost none of the original biodiversity can survive. Indeed, the most popular model used to predict species loss in fragmented forests is island biogeography, which assumes that all area outside of native habitat is uninhabitable. This model may be appropriate for areas of extensive monocultures; however, in many tropical and topographically heterogeneous locations, agricultural landscapes consist of a variety of land uses within a relatively small area. For instance, the area surrounding the Las Cruces station in southern Costa Rica was continuously forested 30 years ago, but has since undergone extensive clearance. Pastures, coffee and banana fields, gardens, and secondary forest now surround fragments of intact forest. In our surveys of a variety of taxa (birds, beetles, butterflies, and moths), we found a substantial fraction of forest biodiversity in the mixed-agricultural countryside. Thus, a "countryside biogeography" model that pays attention to the matrix is needed to predict the distribution of biodiversity in fragmented landscapes. Moreover, there may be simple management practices that would increase the number of species that can persist in human-dominated areas. I give an overview of our results to date and discuss future research directions.

JOHNSTON, R.A.; Dept. of Environmental Science and Policy; University of California; One Shields Ave.; Davis, CA 95616; rajohnston@ucdavis.edu
Urban growth modeling in GIS
             We have developed a GIS-based urban growth model for the Sacramento, California four-county region. It is being used to explore transportation and land use policies for the years 2020 and 2040. This version is interactive, permitting the user to change population growth rates, demographic assumptions, urban land use policies, transportation improvements, and land protection policies. We are applying it to Sonoma, Fresno, and San Diego counties next. It is in the public domain. Software requirements are ArcView with Spatial Analyst. It requires only data now available for the whole state.

JONES, W.J.; Department of Biology; University of California, Santa Cruz; A316 EMS; Santa Cruz, CA 95064; jones@biology.ucsc.edu
Phylogenetic relationships and evolutionary significant units of California roach.
             We sampled remnant populations of California roach (Lavinia symmetricus) in order to determine if these populations represent evolutionary significant units (ESU) and thus separate management units for conservation. We utilized mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) intron sequence data to determine both phylogenetic relationships and genetic divergence between populations. The implications for conservation measures for rare populations such as the "Red Hills" roach will be discussed.

KEITT, B.S., TERSHY, B.R., and CROLL, D.A.; Department of Ocean Sciences; EMS A316 University of California, Santa Cruz CA 95064; bkeitt@cats.ucsc.edu; *Institute of Marine Sciences; University of California, Santa Cruz CA 95064
Ecology and Conservation of the Black-vented Shearwater (Puffinus opisthomelas)
             Introduced predators on islands are the leading cause of local and global avian extinctions. Seabirds are likely to be particularly vulnerable to predation because of life history characteristics including low adult mortality, low fecundity, extended breeding period, and behaviors such as general naiveté with predators. I studied the life history and breeding biology of the Black-vented Shearwater (Puffinus opisthomelas) on Natividad Island, Baja California Sur, Mexico in order to examine the vulnerability of this species to introduced feral cats. I report the first detailed data for this species on population size, breeding phenology, chick growth, and mortality. I estimated the feral cat predation rate on shearwaters for different cat populations on the island from an allometric equation for eutherian mammal energetics. Using additional life history data from the closely related Manx Shearwater (Puffinus puffinus), I created a demographic model to evaluate the effects of different cat populations on the shearwater population's annual growth rate. Black-vented Shearwaters attend the colony at Natividad Island for at least 10 months of the year. In 1997, 76,570 pairs of Black-vented Shearwaters bred on Natividad Island. Egg laying began in March in 1997 and in April in 1998. Incubation and chick rearing lasted 51 and 69 days, respectively. The demographic model estimated the annual population growth for Black-vented Shearwaters to be 1.006 in the absence of cat predation. Factoring in cat predation, I estimate that annual growth rate declines approximately 5% for every 20 cats in a population of 150,000 birds. Persistence times of bird colonies decrease dramatically both with an increase in the feral cat population and with decreasing initial bird population. Removal of introduced animals from seabird islands can greatly increase annual population growth rates of resident seabird species and have long term implications for the conservation of these species.

KELLY, M.J. and *DURANT, S.M.; Department of Wildlife, Fish, and Conservation Biology; University of California at Davis; Davis, CA 95616; mjkelly@ucdavis.edu;*Institute of Zoology; Zoological Society of London; Regent's Park; London NW1 4RY; UK
Population viability analysis for Serengeti cheetahs
             Ecological studies have shown that predation on Serengeti cheetahs accounts for 73% of cub mortality. A previously published model of birth, death, and recruitment suggested that this juvenile mortality was responsible for limiting population growth in this species. Later, a different study examined the sensitivity of the deterministic population growth rate for Serengeti cheetahs and found adult survival to be the prime factor affecting the viability of the cheetah population. In this study, we provide a more thorough and complete analysis of cheetah population dynamics in order determine the viability of the species. We parameterize our model with values based on 20 years of field data and compare our model projections to the actual data. First, we briefly revisit the sensitivity of deterministic growth rate. However, populations that on average are stable or have positive population growth, are still subject to stochastic decline or extinction. Therefore we use simulation modeling to analyze extinction risk based on our variance estimates from our field data. In addition we examine the sensitivity of extinction risk to changes in the demographic parameters and to changes in the variance surrounding those parameters. Our results confirm that the population growth rate is most sensitive to changes in adult survival, followed by juvenile survival. In addition, extinction risk is also most sensitive to changes in adult survival. However, in the Serengeti, adult cheetahs are well protected from poaching within the park boundaries while juvenile cheetahs continue to suffer high predation primarily from lions. We therefore used our demographic records to simulate the effect of different numbers of lions on juvenile survival. High lion abundance dramatically increased extinction risk.

KIMURA, M.; Center for Tropical Research; Department of Biology; San Francisco State University; 1600 Holloway Avenue; San Francisco, CA 94132; kimura@sfsu.edu
Using molecular markers to match breeding and wintering populations of Wilsonia pusilla (Wilson's warbler).
             A central problem in understanding possible declines of Neotropical/Nearctic migratory songbirds has been the inability to distinguish and relate discrete populations on both the breeding and wintering grounds. Without this information it is impossible to know if environmental changes on wintering grounds are impacting declining breeding populations or vice versa. Using molecular genetic techniques we examined over 150 individuals of Wilsonia pusilla (Wilson's warbler), a common Neotropical/Nearctic migrant, from breeding sites in the U.S. and Canada and wintering sites in Mexico and Central America. Mitochondrial cytochrome b sequences were obtained primarily from feather samples. Despite evidence of gene flow, preliminary results show structuring across both the breeding and wintering range. In addition, we found associations between specific breeding and wintering sites. Our results indicate that molecular techniques can be a valuable method for following migratory birds through their annual cycle.

MARSH, D.M. and *TRENHAM, P.C.; Department of Environmental Science and Policy; One Shields Ave.; University of California, Davis; Davis, CA 95616; dmmarsh@ucdavis.edu; *EPA/NHEERL; Mid-Continent Ecology Division; 6201 Congdon Blvd.; Duluth, MN 55804
Do amphibians exhibit metapopulation dynamics and does it matter?
             Recent empirical literature has focused on the importance of analyzing population dynamics from a metapopulation perspective. A number of these studies have examined the spatial dynamics of pond-breeding amphibians, in which local breeding aggregations are considered as sub-populations within larger multi-pond metapopulations. We review the literature on amphibian spatial dynamics and ask the following questions: 1) To what extent can metapopulation concepts apply to organisms that use several different habitats? 2) What life-history characteristics are associated with high levels of turnover in amphibian populations? 3) Is turnover in amphibian populations likely due to extinction and recolonization or to the movements of individuals? 4) What are the consequences of different kinds of spatial dynamics for the monitoring of amphibian populations? 5) What are the consequences of different kinds of spatial dynamics for projections of amphibian population persistence? We conclude with a discussion of the parameters that are most likely to be important in determining the relationship between local (i.e. within-pond) dynamics and spatial patterns observed over larger spatial and temporal scales.

MITCHELL, B.R.; Department of Environmental Science, Policy and Management; University of California, Berkeley; 151 Hilgard Hall #3110; Berkeley, CA 94720; bmitchel@nature.berkeley.edu
San Joaquin kit foxes - doomed to extinction?
             Kit foxes are the smallest canids in North America, and the San Joaquin kit fox (Vulpes macrotis mutica) has been listed as endangered since 1967. I will present the results of a recent population viability analysis (PVA) of the San Joaquin Kit Fox. The PVA was based on a stochastic metapopulation model that allowed me to investigate the sensitivity of demographic and metapopulation parameters. Particular emphasis was placed on the influence of predation and predator control, as well as survival outside of patches. I also investigated how using a female only versus a male and female model affected the model's results.

NILES, J.O.; Center for Conservation Biology; Stanford University; Stanford, CA 94305-5020; jniles@leland.Stanford.EDU
Carbon conservation: financing biodiversity with the Kyoto Protocol
             Tropical deforestation accounts for approximately 20% of greenhouse gas emissions. This presentation will explore the linkage between biodiversity and climate change in the context of the Kyoto Protocol. The global warming potential (gwp) of emissions from deforestation will be compared to emissions from fossil fuels. Biogeochemical and ecological principles will support strengthening the Protocol's tropical forest conservation instruments.
             A brief analysis of the Protocol's Clean Development Mechanism (CDM) will demonstrate the enormous potential for financing biodiversity and carbon conservation. Finally, a benefit-cost analysis of Madagascar's largest remaining tropical forest will provide optimistic evidence for actually implementing forest and carbon conservation. Concluding remarks will address specific policy recommendations to make the Clean Development Mechanism even cleaner.

PARKS, D., MAHONEY, M.J., and FELLERS, G.M.; Department of Integrative Biology; University of California, Berkeley; Berkeley, CA 94720; dparks@uclink4.berkeley.edu
Mitochondrial DNA sequence documents artificial introduction of two lizards to the Channel Islands of California
             The side-blotched lizard, Uta stansburiana, and the southern alligator lizard, Elgaria multicarinata are both found on several of the Channel Islands off the coast of southern California. We used DNA sequence from the mitochondrial cytochrome b gene to identify probable mainland source populations for island populations of both these lizards and to estimate the times of their divergence. In two or three cases, it appears that island populations are not native to the Channel Islands, but rather arrived this century as inadvertent introductions associated with human activity on the islands. We discuss likely modes of introduction and the conservation implications of these findings.

RICKETTS, T.H., DAILY, G.C. and EHRLICH, P.R.; Center for Conservation Biology; Department of Biological Sciences; Stanford University; Stanford, CA 94305-5020; ricketts@leland.stanford.edu
The matrix matters: effective isolation for populations in patchy habitats.
             One of the most pressing challenges in conservation biology is to understand the effects on native organisms when areas of intact habitat are reduced to remnant patches surrounded by human-dominated matrix. Island biogeography and metapopulation theories have dominated the conservation thinking in such landscapes. These models usually assume that the matrix surrounding the habitat fragments is uniform (i.e. seawater) and measure isolation among patches simply as the distance between them. Terrestrial patchy habitats, however, are not embedded in a uniform matrix, but instead are surrounded by a complex mosaic of other land cover types. These varied matrix types may be differentially permeable to dispersing individuals, impeding or allowing movement among the patches to different degrees. Habitat patches therefore may be more or less effectively connected than simple distance would indicate (and classic models would predict), depending on the type of intervening matrix habitat.
             We tested this idea with a mark-release-recapture experiment on 22 species of butterflies in sub-alpine Colorado. The butterflies exist in a system of meadow patches separated by two main types of matrix habitat: willow thicket and conifer forest. We found that butterflies more often cross between pairs of sites separated by willow thicket than by conifer stands, supporting the idea that matrix type can influence the effective isolation of a patch. The matrix response differed among taxonomic groups within the butterflies, suggesting that the matrix will influence different taxa differently. Finally, the number of transfers over meadow decreased significantly with increasing distance, but the number of transfers over willow or spruce was not related to distance. Thus distance appears to be important to dispersal frequency within habitat, but not when crossing out of it. This suggests that boundary effects may be at least as important as distance in determining dispersal success across non-habitat. Within these results lies an important policy implication: perhaps in fragmented landscapes, when restoring large amounts of native habitat is impractical, connectivity among remnant patches may be increased with careful management of the matrix surrounding the remnants. In other words, the effective isolation of fragments may be reduced without changing the actual distances among them.

RUBINOFF, D.; Department of Environmental Science Policy and Management; University of California, Berkeley; Berkeley, CA; drubinof@nature.berkeley.edu
The California gnatcatcher as an umbrella species for three coastal sage scrub-dependent Lepidoptera
             The federally listed California Gnatcatcher has been used as an umbrella species for the conservation of the southern California coastal sage scrub fauna. This action is commensurate with a general conservation paradigm of using vertebrates and vertebrate-based reserve designs to de facto protect invertebrate cohabitants. Over the past four and a half field seasons I have monitored 50 patches of coastal sage scrub in central and northern San Diego county. Patches surveyed varied from less than a hectare to several hundred hectares in size and arrangement. I have surveyed each patch repeatedly for three species of sage-scrub dependent Lepidoptera: Apodemia mormo (Mormon metalmark), Euphilotes bernardino (Bernardino blue), and Hemileuca electra (Electra buckmoth). Initial results indicate that the presence of the gnatcatcher may not be a good indicator for the presence of these insects; only the largest habitat patches supported all three species of Lepidoptera. Future conservation plans, not only in the sage scrub but in any biological community where invertebrate conservation is important, take insect preservation for granted at their peril.

SANDERCOCK, B.K.; Department of Environmental Science, Policy and Management; University of California at Berkeley; 151 Hilgard Hall; Berkeley, CA 94720-3110; bsanderc@nature.berkeley.edu
The demography of a small neotropical parrot: lessons for population viability analysis
             Parrots are threatened worldwide by habitat loss and harvesting for the pet trade, but little is known about the demography of most species. Here, I report on the age-specific fecundity and survival of the Green- rumped Parrotlet (Forpus passerinus), a small, monogamous species that has been studied in central Venezuela for the past 11 years. Parrotlets are secondary cavity-nesters like most psittacines, and readily use artificial nest boxes at our study site. The sex-ratio of the population was male-biased in all years (1:1.7), and a large proportion of both sexes were nonbreeders (20-50%). Females began breeding as yearlings and reproductive performance increased until 2 years of age, whereas males entered the breeding population at older ages, and increased performance until 3 years of age. Multistate models for analysis of mark-recapture data were used to estimate survivorship, and I discuss the importance of these methods for PVA. Overall, breeders had higher rates of local survival, breeding propensity and detection rates than nonbreeders. I integrate these age-specific vital rates into a simple deterministic population model, and discuss the implications of this model for the conservation of parrots and other tropical birds.

SEKERCIOGLU,, C.H.; Center for Conservation Biology; Department of Biological Sciences; Stanford University; Stanford, CA 94305-5020; cagan@leland.Stanford.EDU
The effects of selective logging and a conifer plantation on the vegetation structure and the bird community of the Kibale Forest, Uganda
             The effects of past timber management practices on the vegetation structure and the forest bird community of the Kibale Forest National Park of western Uganda were examined. 2 forest sites that had been selectively logged at different intensities in the late 1960’s and an abandoned conifer plantation were compared to an unlogged control site. At the heavily-logged site, high levels of selective logging caused significant long-term (30 years or more) changes in the vegetation structure, including reductions in canopy cover, tree density, basal volume, diversity of tree-sizes, and heterogeneity of vertical vegetation distribution, as well as increases in undergrowth density and heterogeneity of tree distribution. The conifer plantation, compared with the native forest sites, has lower levels of tree recruitment. Tree size (diameter-at-breast-height), diversity and heterogeneity of spatial distribution of trees are all significantly lower in the plantation than those observed at the other sites. Forest birds were best represented at the unlogged site. There is no significant difference between the unlogged and lightly-logged sites in terms of bird diversity. In the conifer plantation, bird species diversity, especially that of the primary forest birds, is about a third of that observed in the other sites. A vegetational structural integrity index comprised of five vegetational variables correlated significantly with the number of primary forest species observed at each site. There was a significant correlation between the amount of vegetation in the upper forest layers and increased representation of primary forest birds. Overall, the heavily-logged site and the conifer plantation exhibited long-lasting differences in terms of vegetational structure and bird community composition with respect to the less-disturbed primary forest sites, and recommendations are made for decreasing the impact of selective logging practices on tropical forests.

STEFANI, R.A.; Department of Environmental Science and Policy; University of California Davis; One Shields Avenue; Davis, CA 95616; rastefani@ucdavis.edu
Historic and contemporary status of the Swainson's Thrush population in the Sierra Nevada: conservation and restoration implications
             In the 1850's through the late 1880's, the Swainson's Thrush (Catharus ustulatus) was a common bird species in the Sierra Nevada mountains. Today, this thrush is extremely local in distribution and uncommon to rare in these mountains. Hypotheses for the decline of this riparian-obligate, highly philopatric species in the Sierra Nevada will be presented. The current population trend of the Sierran Swainson's Thrush as well as conservation and restoration strategies to enhance the species' protection in the Sierra will be discussed.

SWANSON, C., YOUNG, P.S., and CECH Jr., J.J.; Department of Wildlife, Fish, and Conservation Biology; University of California, Davis; One Shields Avenue; Davis, CA 95616; cswanson@ucdavis.edu
Swimming behavior of delta smelt in complex flows: applications for fish screens
             Delta smelt (Hypomesus transpacificus) are vulnerable to entrainment and impingement at water diversions in the Sacramento-San Joaquin estuary. In order to help develop fish screen flow and design criteria that better protect this species, we examined performance and swimming behavior of delta smelt in complex flow regimes similar to those near screened water diversions in a large annular flume (4 m diameter) equipped with a fish screen. In nine flow regimes derived from combinations of 6, 10, and 15 cm/s approach velocity (through the screen) and 0, 31, and 62 cm/s sweeping velocity (past the screen) and a control (0 cm/s approach and sweeping velocity) (experiment duration: 2 h, 20 fish per experiment, 19 °C), we measured screen contacts by the fish, impingement, location relative to the screen, swimming velocity, rheotaxis, velocity past the screen, and post-experiment survival and injury. Preliminary results show that in all flow regimes except the control, delta smelt experienced frequent contact with the screen and contact rate was directly related to the approach and sweeping velocities, and duration of exposure. In approaching velocities of greater than 6 cm/s, some fish became impinged on the screen, unable to escape. These fish were invariably dead or moribund by the end of the experiment. Injury rates and delayed mortality (48 h post-experiment) were directly related to screen contact rates. Delta smelt consistently swam rheotactically and swimming velocity increased with both the approach and sweeping components of the flow regime. In high velocity flows, the fish swam at velocities comparable to maximum sustained swimming velocities measured for this species in smaller flumes. Consequent to this high-velocity, rheotactic swimming, screen passage velocities were low at the intermediate sweeping velocity (31 cm/s), indicating that the fish could experience prolonged screen exposure in these flow regimes. Screen passage velocity increased at the higher sweeping flow but, compared to lower sweeping velocities, the fish suffered more frequent and severe screen contacts. These results have applications for developing fish screen criteria, including approach and sweeping velocity criteria, screen length, and allowable exposure duration that minimize harm to this threatened fish. Research funded by the California Department of Water Resources.

VREDENBURG, V.T.; Museum of Vertebrate Zoology, Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720; vancev@socrates.berkeley.edu
Amphibian declines in the high elevation Sierra Nevada Mountains of California: Experimental tests of two hypotheses, introduced predators and UV- B radiation.
             Amphibians have been disappearing at an alarming rate all over the world, but not all species appear to be affected even in the most troublesome areas. Most alarming is that many extinctions and population crashes have occurred in protected habitat. California has been no exception, amphibians, particularly frogs, have been declining even in our national parks. For example in the high elevation areas of the Sierra Nevada Mountains there are three native anurans, the Yosemite toad (Bufo canorus), the mountain yellow-legged frog (Rana muscosa), and the Pacific tree frog (Hyla regilla). Of these, the Yosemite toad is endangered, the mountain yellow-legged frog is threatened, and the pacific tree frog appears not to be affected and is very common. Using field experiments I am testing two hypotheses for amphibian decline, the introduction of non-native predators, and the effects of UV-B radiation on egg hatching success. Last summer I conducted field exposures of R. muscosa and H. regilla embryos to fractions of ambient UV-B radiation at three different sites. I found no differences in hatching success among the treatments. Next summer I will repeat these experiments and will include Bufo canorus. The high elevation Sierra Nevada was historically fishless due to glaciation. Over the years, land managers have introduced trout into the region for sport fishing. In addition to the UV tests, I am testing the direct and indirect effects of fish presence using a combination of fish removal and addition experiments as well as frog behavior and movement studies. My results indicate that introduced trout have little or no effect on pacific tree frogs and Yosemite toads, but have a significant negative effect on mountain yellow-legged frogs. To reverse population declines of mountain yellow-legged frogs in the high Sierra, land managers should eliminate current fish planting efforts and should make plans to remove introduced fish from areas still containing sensitive frog populations.

WALL, D.P.; Department of Integrative Biology; University of California, Berkeley; Berkeley, CA 94720; dpwall@socrates.berkeley.edu
Indicators of effective conservation in South Pacific islands
             With the current population growth rate and associated agricultural and developmental expansion, floristic exploration and effective conservation of South Pacific islands has become increasingly urgent. Several international efforts, (most notably, the South Pacific Environmental Protection Agency (SPREP)) have initiated sustainable conservation programs, but the benefits of these remain unknown. To date, no precise and fast measures of success exist to assess conservation areas under SPREP’s control. Bryophyte species tend to be highly specific to particular microenvironments (responding to such features as temperature, light and water availability, substrate chemistry, etc.), making them good ecological indicator species. In fact, recent data reported here show strong correlations of elevational gradients (from 0m-890m) with moss distribution patterns, substrate specificity in many taxa, and pronounced vertical zonation of moss epiphytes on natives such as Cocos nucifera. Although bryophytes are attracting much attention recently from applied ecologists and conservation biologists in temperate areas, these plants have received almost no attention in the South Pacific paleotropics. Those South Pacific areas remain virtually unexplored for bryophytes and of the few studies completed, few have focused on ecology in addition to taxonomic inventory. This study: 1) identifies mosses and other bryophytes as accurate indicators of effective conservation; 2) reports findings on studies from two expeditions to the South Pacific ranging from Tahiti, French Polynesia, to New Caledonia, Fiji, and Samoa where conservation programs are underway but whose effectiveness remains unassessed; 3) provides simple techniques for assessing conservation areas using moss. The preliminary findings reported here, although insufficient, provide potential new avenues for agencies like SPREP to assess their conservation programs’ effectiveness and whether the current use of biodiversity is truly sustainable.

WEINSTEIN, A., CARLTON, J. and COHEN, A.; Center for Biological Invasions; San Francisco Estuary Institute; 180 Richmond Field Station; 1325 South 46th Street; Richmond, CA 94804; anna@sfei.org
Aquatic bioinvasions in the San Francisco Estuary
             The San Francisco Estuary, one of the largest estuarine and freshwater ecosystems in North America, may be the most invaded estuary in the world. There are at least 234 exotic species established in the ecosystem, and an additional 125 are neither clearly native nor clearly exotic. Vectors of introduction include ballast water discharge, the importation of baitworms, and intentional introduction. In some regions of the bay, 100% of the common species are introduced. These invasions have had a profound impact on the ecology of the region, and are strongly contributing to the further demise of endangered marsh birds and mammals. Once established in the Estuary, these organisms may then spread to other estuaries and watersheds along the Pacific Coast. Furthermore, the rate of invasions continues to increase. Traditionally, public agencies have focused on controlling important exotic species after they have already established. Recently, however, concerned scientists and environmental advocacy groups have begun pressing agencies to focus more attention on preventing exotic species introductions to the San Francisco Estuary and the rest of California, and regulators and stakeholders are beginning to respond.

WEISS, S.B.; Center for Conservation Biology; Department of Biological Science; Stanford University; Stanford, CA 94305; stu@bing.stanford.edu
Cars, cows, and checkerspot butterflies: nitrogen deposition and grazing management of serpentintic grasslands for a threatened species
             Nitrogen deposition from air pollution may be a major threat to the integrity of nature reserves, because nitrogen is often a limiting nutrient for plant growth. Nutrient-poor serpentinitic soils in the San Francisco Bay Area sustain a diverse native grassland supporting many rare species, including the Bay checkerspot butterfly, Euphydryas editha bayensis. Several populations of this butterfly in south San Jose crashed following the removal of cattle grazing. Nearby populations under continued grazing did not suffer similar declines. The immediate cause of the population crashes was rapid invasion by introduced annual grasses that crowded out the larval host plants of the butterfly. However, ungrazed serpentinitic grasslands on the San Francisco Peninsula have largely resisted grass invasions for nearly four decades. Several lines of evidence indicate that dry nitrogen deposition from smog is responsible for the observed grass invasion. Fertilization experiments have shown that soil nitrogen limits grass invasion in serpentinitic soils. Estimated deposition rates in south San Jose grasslands are 10-15 kg N ha-1 yr-1; Peninsula sites have lower deposition (4-6 kg N ha-1 yr-1). Grazing cattle select grasses over forbs, and grazing leads to a net export of nitrogen as catlle are removed for slaughter. While poorly-managed cattle grazing can significantly disrupt native ecosystems, in this case moderate well-managed grazing is essential for maintaining native biodiversity in the face of invasive species and exogenous inputs of nitrogen from nearby urban areas.

WILLIAMSON, E. and SLATKIN, M.; Department of Integrative Biology; U.C. Berkeley; 3060 VLSB; Berkeley, CA 94720-3141; ellenw@socrates.berkeley.edu
Using maximum likelihood to estimate population size from temporal changes in allele frequencies
             In this study, we developed a maximum likelihood framework for using temporal changes in allele frequencies to estimate the number of breeding individuals in a population. We compared this estimator to an F-statistic estimator of variance effective population size using simulations. In these comparisons the maximum likelihood estimator typically had a lower variance and smaller bias. Taking advantage of the flexibility of the likelihood framework, we extended the model to include population growth and found that in some cases, temporal allele frequency data can also be used to test for growth.