Download or read book Habitat Fragmentation and Woodland Amphibians written by Shauna L. Weyrauch and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Recent declines in amphibian populations have heightened the importance of understanding amphibian/habitat relationships. Because of poor dispersal abilities and physiological constraints, amphibians may be especially susceptible to the effects of habitat fragmentation. In this dissertation, I investigate landscape-level influences of fragmentation on woodland amphibian species distributions, as well as population-level impacts on genetic diversity and related fitness consequences for wood frogs (Rana sylvatica). For the first part of my research, I surveyed 25 woodlots and one area of continuous forest in Crawford County, Ohio for amphibians and evaluated 13 models concerning amphibian species richness and the presence of individual species in woodlots. I found 13 species of amphibians within the study plot, indicating that small woodlots within an agricultural matrix are important amphibian refuges. Hydroperiod was the most important habitat characteristic for predicting species richness. Landscape characteristics were relatively unimportant. Next, I analyzed the genetic diversity of wood frog populations in relation to characteristics of their local habitat and landscape, to determine whether populations within woodlots have become genetically differentiated and/or have lost genetic diversity. I found genetic distance to be correlated with geographical distance. Populations from breeding ponds with longer hydroperiods were more genetically diverse. I also assessed the genetic diversity of eight wood frog populations, and compared the genetic diversity of each population with the mortality and deformity rates of lab-reared eggs and larvae. Although there were weak negative correlations, my analyses failed to find a significant relationship between genetic diversity and deformity or mortality rates. The final component of my research was an investigation of a synergism between UV-B radiation and genetic diversity, influencing mortality and deformity rates in wood frogs. I measured the genetic diversity of 12 populations, and exposed eggs/larvae from those populations to three different UV-B treatments. UV-B exposure significantly increased larval mortality and deformity rates. Populations with low genetic diversity suffered greater egg and larval mortality rates and deformity rates. Further, the interaction between UV-B treatment and genetic diversity significantly influenced larval mortality rates. This is the first study to document such an interaction between genetic diversity and resistance to an environmental stressor.
Download or read book The Ecology and Behavior of Amphibians written by Kentwood D. Wells and published by University of Chicago Press. This book was released on 2010-02-15 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Consisting of more than six thousand species, amphibians are more diverse than mammals and are found on every continent save Antarctica. Despite the abundance and diversity of these animals, many aspects of the biology of amphibians remain unstudied or misunderstood. The Ecology and Behavior of Amphibians aims to fill this gap in the literature on this remarkable taxon. It is a celebration of the diversity of amphibian life and the ecological and behavioral adaptations that have made it a successful component of terrestrial and aquatic ecosystems. Synthesizing seventy years of research on amphibian biology, Kentwood D. Wells addresses all major areas of inquiry, including phylogeny, classification, and morphology; aspects of physiological ecology such as water and temperature relations, respiration, metabolism, and energetics; movements and orientation; communication and social behavior; reproduction and parental care; ecology and behavior of amphibian larvae and ecological aspects of metamorphosis; ecological impact of predation on amphibian populations and antipredator defenses; and aspects of amphibian community ecology. With an eye towards modern concerns, The Ecology and Behavior of Amphibians concludes with a chapter devoted to amphibian conservation. An unprecedented scholarly contribution to amphibian biology, this book is eagerly anticipated among specialists.
Download or read book The Biology of Amphibians and Reptiles in Old growth Forests in the Pacific Northwest written by and published by . This book was released on 1995 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Forest Fragmentation written by James Arthur Rochelle and published by BRILL. This book was released on 1999-01-01 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book contains 15 chapters and provides an overview and synthesis of forest fragmentation and its influences on key ecological processes and vertebrate productivity. Land use practices and their effects on vertebrate populations and productivity are discussed and examples of several planning approaches to address landscape-level management effects are described.
Download or read book Effects of Habitat Fragmentation on Reptiles and Amphibians in Coastal Sage Scrub and Grassland Communities written by Gary Toshihiko Busteed and published by . This book was released on 2003 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fragmentation in the Boreal Forest and Possible Effects on Terrestrial Wildlife written by Christopher Herbert Richard Wedeles and published by . This book was released on 2008 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Natural History of Amphibians written by Robert C. Stebbins and published by Princeton University Press. This book was released on 1997-01-26 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amphibia, the animal group that includes frogs, toads, salamanders, and caecilians, contains more than 4,500 known living species and new ones are being discovered continuously. This book focuses on the natural history of amphibians worldwide, how interaction with their environment over time has affected their evolutionary processes and what factors will determine their destinies. 37 photos. 52 line illus.
Download or read book Influence of Forest Management on Headwater Stream Amphibians at Multiple Spatial Scales written by Margo A. Stoddard and published by . This book was released on 2004 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Amphibian Conservation written by Rebecca K. Smith and published by Pelagic Publishing Ltd. This book was released on 2014-05-16 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amphibian Conservation is the fourth in the series of Synopses of Conservation Evidence, linked to the online resource www.ConservationEvidence.com. This synopsis is part of the Conservation Evidence project and provides a useful resource for conservationists. It forms part of a series designed to promote a more evidence-based approach to biodiversity conservation. Others in the series include bee, bird, farmland and bat conservation and many others are in preparation. Approximately 32% of the 7,164+ amphibian species are currently threatened with extinction and at least 43% of species are declining. Despite this, until recently amphibians and their conservation had received little attention. Although work is now being carried out to conserve many species, often it is not adequately documented. This book brings together and summarises the available scientific evidence and experience relevant to the practical conservation of amphibians. The authors consulted an international group of amphibian experts and conservationists to produce a thorough summary of what is known, or not known, about the effectiveness of amphibian conservation actions across the world. "The book is packed with literature summaries and citations; a veritable information goldmine for graduate students and researchers. It also admirably provides decision makers with a well-researched resource of proven interventions that can be employed to stem/reverse the decline of amphibian populations." -John G Palis, Bulletin of the Chicago Herpetological Society
Download or read book Management of Amphibians Reptiles and Small Mammals in North America written by Robert C. Szaro and published by . This book was released on 1988 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: Historically the management of public lands from a multiple use perspective has led to a system that emphasizes those habitat components or faunal elements that primarily resulted in some sort of definable economic value. While this often benefitted other species that were not even considered in the original prescriptions, it also negatively impacted others. We no longer can afford to take this simplistic view of ecosystem management. We need to use a more holistic approach where ecological landscapes are considered as units, and land management practices incorporate all elements into an integrated policy. This includes examining the impacts of proposed land uses on amphibian, reptile, and small mammal populations.
Download or read book A Framework for Amphibian Habitat Conservation Across Spatial Scales Using Community Occupancy Models written by Vishnupriya Sankararaman and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Agricultural intensification and loss of native forest habitats have presented the most ubiquitous threats to faunal communities across the world. These land use modifications have caused loss of species richness, genetic diversity, biotic homogenization, and increased dominance structure from local, regional to global scales. Amphibians are amongst the most endangered vertebrate groups with high susceptibility to habitat modification. Their biphasic life history, poor mobility and low tolerance to chemical pollutants make it difficult for most species to adapt to intensively managed land uses. To combat pressures from habitat loss, commodity agroforests are recommended as suitable secondary habitats for many threatened faunal communities. However, there is little applied research on how individual land management strategies at various spatial scales can help design more wildlife-friendly landscapes. The research presented in this dissertation, uses community ecology theory to examine: (1) how land use gradients shape amphibian species and communities across local and regional spatial extents, (2) how individually evolved life history strategies influence adaptations to different habitats and land uses, (3) how conservation objectives and decisions can shape land use design in terrestrial and aquatic environments to maximize conservation potential of agroforests. In the first chapter, I studied patterns in alpha and beta diversity across areca, coffee and rubber agroforests across Karnataka's Western Ghats. A total of 106 agroforests across a 30,000 km2 landscape were surveyed for amphibians, and a multispecies occupancy model approach was used to analyze and estimate community-level and species-specific parameters. The broad-scale influence of elevation and latitude and fine-scale influences of microhabitat availability were examined on species occurrences. The availability and heterogeneity of microhabitats were also used to predict species occurrences. Overall, a heterogenous land use such as shade-grown coffee hosted much higher species richness than the more intensively managed areca and rubber agroforests. Our results indicate that site-specific diversity can be enhanced with careful management. The preservation of aquatic and terrestrial microhabitats can increase amphibian species richness by up to 75% in each agroforest. The second chapter focuses on examining the influence of life history traits on species occupancy and community structure across terrestrial and stream habitats in different land uses. I surveyed 223 transects for amphibians across tea, coffee and forest fragments in the Anamalai Hills of the Western Ghats. A joint-species distribution model was used to estimate species occupancies and cooccurrence patterns. Species richness was highest in forest fragments followed by coffee and lowest in tea agroforests. Life-history traits clearly defined habitat use, with fast-water breeding amphibians preferring forested streams first, followed by streams in coffee and the lowest occupancy was observed in tea streams. Slow-water breeding amphibians showed a reverse trend with higher preference for tea over coffee and forest stream sites. The study also revealed important patterns in species distributions across elevational ranges and the influence of annual climate patterns on amphibian populations. The results from this chapter highlight the importance of focusing conservation attention on amphibians with torrential habitat associations as they are the most vulnerable to land use intensification. In chapter three, I advance the understanding of amphibian community structure at broader spatial scales. Using results from chapter two, I estimate pairwise species dissimilarity across sites and examine the role of geographic distances, environmental distances, watershed aspects and land use on beta diversity. The mean beta diversity was lowest for within forest sites and highest for comparisons between coffee and forests. Also, terrestrial habitats displayed greater heterogeneity in species compositions than stream habitats. Rather than geographic distances, the difference in elevation was one of the strongest predictors of beta diversity patterns at the regional scale. The combined influences of the different predictors indicate that prioritizing conservation management across different land uses, elevation gradients and watersheds will be most effective in maintaining the regional diversity and heterogeneity of amphibian communities in the Anamalai Hills. Finally, in the fourth chapter, I use results from all three previous research findings with additional information about ecosystem services to identify where riparian forest restoration can have optimal conservation outcomes. Prioritization was based on predicted increase in alpha diversity, and topographic wetness index (TWI), along with elevational attributes. Five alternate scenarios were set up based on these criteria. The results were tested on ten coffee sites, ten tea sites and a combination of five coffee and tea sites. Species richness was revealed to be a poor criterion for prioritization as it resulted in the most spatially aggregated portfolio of sites and with lowest predicted gamma diversity. Incorporating TWI in land use prioritization yielded much higher gamma diversity and ecosystem function benefits. I also discuss the socioeconomic implications of restoring riparian buffers for private land owners in the region and propose mechanisms by which the restoration costs can be managed. Conservation management has to be scale dependent and rely on local and regional studies to provide empirical evidence for how decisions influence outcomes. I used a combination of theories in community ecology with applied conservation science to provide greater understanding of fine-scale and broad-scale factors influencing agrobiodiversity. This research also expands the use of hierarchical community occupancy models to examine different aspects of spatial variations in multispecies assemblages, particularly in poorly-studied and hyper-diverse tropical regions.
Download or read book Amphibian Declines written by Michael J. Lannoo and published by Univ of California Press. This book was released on 2005-06-15 with total page 1124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Documents in comprehensive detail a major environmental crisis: rapidly declining amphibian populations and the disturbing developmental problems that are increasingly prevalent within many amphibian species.
Download or read book Habitat Fragmentation and Landscape Change written by David B. Lindenmayer and published by Island Press. This book was released on 2013-02-22 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: Habitat loss and degradation that comes as a result of human activity is the single biggest threat to biodiversity in the world today. Habitat Fragmentation and Landscape Change is a groundbreaking work that brings together a wealth of information from a wide range of sources to define the ecological problems caused by landscape change and to highlight the relationships among landscape change, habitat fragmentation, and biodiversity conservation. The book: synthesizes a large body of information from the scientific literature considers key theoretical principles for examining and predicting effects examines the range of effects that can arise explores ways of mitigating impacts reviews approaches to studying the problem discusses knowledge gaps and future areas for research and management Habitat Fragmentation and Landscape Change offers a unique mix of theoretical and practical information, outlining general principles and approaches and illustrating those principles with case studies from around the world. It represents a definitive overview and synthesis on the full range of topics that fall under the widely used but often vaguely defined term "habitat fragmentation."
Download or read book Conservation Studies of Amphibian Health at Individual Population and Landscape Scales written by Rebecca Newcomb Homan and published by . This book was released on 2003 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Habitat loss is one important cause of observed worldwide amphibian declines. I investigated several potential mechanisms by which habitat loss might increase vulnerability of pond-breeding amphibians. (1) First, I compared demographic characteristics of spotted salamanders (Ambystoma maculatum) and blue-spotted salamanders (A. laterale), including sex ratios, reproductive output, and adult survival to determine if these traits make them differentially vulnerable. Although blue-spotteds were more populous than spotteds, and had similar adult survival, their sex ratios were more skewed, they had lower reproductive output, lower recruitment, and lower survival to emergence, perhaps indicating why blue-spotted salamanders may be more vulnerable. (2) Next, I investigated whether there were thresholds in spotted salamander and wood frog (Rana sylvatica) occurrence associated with levels of upland forest loss and if such relationships differed by spatial scale. I found significantly lower occupancy by spotted salamanders when forest cover dropped to 40--50% or below within 100 m of the pond edge and by both species when forest cover dropped to 10--30% or lower within 300 m. Consequently, habitat protection for these species would be important within 300 m of the pond edge. (3) To determine the degree to which amphibian growth is affected by environmental stochasticity, I investigated correlates of growth in spotted salamanders, using long-bone deposition to estimate yearly growth. Growth varied by age, slowing around the age of reproductive maturity, and was not significantly correlated with year of emergence, capture location, or sex, implying that year- and site-specific environments have little effect on growth. (4) Finally, I measured a stress hormone (corticosterone) in spotted salamanders in an undisturbed habitat, developing a standard hormone profile to determine its efficacy as a biomonitor of environmental suitability. I compared the standard to values from individuals in sites that differed in amount of forest loss, during breeding migration across forest versus pavement, and in microhabitats with various soil and canopy characteristics. Hormone levels differed in animals from habitats with different amounts of forest loss possibly suggesting chronic stress, and males migrating across pavement demonstrated an acute stress response. These results indicate that stress hormones might be promising biomonitors for conservation.
Download or read book Conservation of the Amphibia of the United States written by R. Bruce Bury and published by . This book was released on 1980 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Amphibian Ecology and Conservation written by C. Kenneth Dodd and published by Oxford University Press. This book was released on 2010 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the latest methodologies used to study the ecology of amphibians throughout the world. Each of the 27 chapters explains a research approach or technique, with emphasis on careful planning and the potential biases of techniques. Statistical modelling, landscape ecology, and disease are covered for the first time in a techniques handbook.
Download or read book Landscape Genetics of the Small mouthed Salamander Ambystoma Texanum in a Fragmented Habitat written by Elizabeth Anne Rhoads and published by . This book was released on 2011 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Habitat loss is the leading cause of species declines and extinctions worldwide. Fragmentation of original habitat into patches often accompanies habitat loss and spatially separates breeding populations across a landscape. Habitat fragmentation poses additional challenges for species by degrading habitat quality, altering population abundance and density, and decreasing gene flow among breeding populations in separate patches. Wetland loss and deforestation in western Ohio has fragmented both breeding and terrestrial habitat for woodland amphibians, where agriculture is now the dominant landuse. This project utilized genetic markers to study the effect of habitat fragmentation on the population structure of a woodland amphibian, the small-mouthed salamander (Ambystoma texanum), in Hardin County, Ohio. This species breeds in vernal pools within forest patches, and has low vagility. It was hypothesized that salamanders were not migrating between forest patches; and that populations in different forest patches would show genetic differentiation and small populations would have decreased genetic diversity. A method was developed to screen for unisexual Ambystoma salamanders, which also reproduce in vernal pools in the study area and whose larvae are difficult to distinguish from A. texanum larvae. For the population genetic analysis, a total of 160 A. texanum from eight breeding populations in five forest patches were genotyped for eight highly polymorphic microsatellite loci. The results indicate that all sampled populations have within-population structure, with the two most isolated populations having the highest inbreeding coefficients. Estimates of historical migration rates reveal that gene flow occurred in the past among sites that today show genetic differentiation. Overall our results suggest that forest fragmentation and wetland loss have reduced the connectivity of breeding populations, which supports numerous studies that implicate landscape change as the main threat to species decline.
