Factors Affecting Abundance, Physiology, and Fine-scale Genetic Differentiation of the Western Slimy Salamander (Plethodon Albagula)

Factors Affecting Abundance, Physiology, and Fine-scale Genetic Differentiation of the Western Slimy Salamander (Plethodon Albagula)
Author: William Earl Peterman
Publisher:
Total Pages: 95
Release: 2013
Genre: Electronic dissertations
ISBN:

Inferring process from pattern can be a challenging undertaking when dealing with ecological complexity. The distribution and abundance of organisms on the landscape is often interpreted through the lens of competition, movement, or physiology, as well as interactions with the abiotic environment. Further, movement, distribution, and abundance often coincide with favorable abiotic environments such as temperature, moisture, or nutrients. At its core, landscape genetics seeks to identify the spatial processes shaping the observed patterns of genetic diversity across the landscape, but most landscape genetic studies are predominantly exploratory and lack well-established hypotheses. To increase understanding of process-driven patterns in landscape genetics, I studied the western slimy salamander (Plethodon albagula) in east-central Missouri with three specific questions: (1) Where are salamanders on the landscape, and what environmental factors influence local abundance? (2) Is there a physiological constraint underlying the observed patterns of distribution and abundance? (3) How is spatial genetic structure shaped by abundance and physiology across the landscape? I utilized a combination of abundance modeling, spatial quantification of water loss using plaster of Paris models, and landscape genetics analyses to assess the factors contributing to genetic differentiation across a 1300 ha landscape. Plethodontid salamanders are highly sensitive to water loss, in part due to their lack of lungs and cutaneous respiration. I found that abundance of salamanders was best predicted by canopy cover, topographic position (ridge, slope, ravine), and the interaction between wetness and solar exposure. The spatial relationships of these factors are such that abundance is predicted to be highest in forested ravines with lower solar exposure. Plaster models deployed across the landscape served as surrogates for live salamanders to quantify rates of water loss. I found that rates of water loss across the landscape were inversely related to predicted abundance, suggesting that water loss is likely a physiologically-limiting process underlying the distribution of salamanders. Finally, I determined that genetic distances were significantly correlated with ecological surfaces, and that the independent landscape features underlying these processes were poor predictors of genetic differentiation. My results highlight the importance of understanding basic ecological and physiological factors as mechanisms for interpreting spatial genetic patterns.

Spatial Variation in the Abundance, Demography, and Physiology of the Montane Endemic Salamander, Plethodon Shermani, and the Consequences of Climate Change

Spatial Variation in the Abundance, Demography, and Physiology of the Montane Endemic Salamander, Plethodon Shermani, and the Consequences of Climate Change
Author: Meaghan R. Gade
Publisher:
Total Pages:
Release: 2021
Genre: Climatic changes
ISBN:

As climate change marches on, it is imperative to understand how species respond via distribution, abundance, physiology, and behavior to their environment present-day in order to inform possible responses in the future. Populations of species exist across heterogeneous environments that may differentially influence particular responses. The scale at which these responses are assessed must be considered because patterns can emerge at a local scale that may not be detectable at broader scales. Yet, only assessing local-scale patterns and responses neglects the broader landscape patterns that ultimately shape fine-scales. Montane biodiversity experience extreme abiotic variation over small spatial scales. To increase our understanding of how these gradients influence wildlife across scales, my research examines the patterns of distribution, abundance, demographic life-history traits, behavior, and physiology in the red-legged salamander, Plethodon shermani, across multiple abiotic gradients in the Southern Appalachian Mountains. The primary objectives of my research are to (1) understand the effects of spatial patterns on ecological responses of P. shermani and (2) use that knowledge to predict how responses will change in the future. Terrestrial Plethodon salamanders lack lungs and depend on cool and moist microhabitat to facilitate gas exchange across their skin surface. As such, salamanders are restricted to specific habitats. We know that salamander abundance increases with elevation due to the cool and moist regional climate at high elevations. However, my research investigates the role of both elevation and stream distance gradients as broad and fine-scale abiotic gradients, respectively, that salamanders may be responding. Although low elevations are regionally warm and dry, microhabitats near streams are buffered and tend to be cooler and wetter. I found that salamander distribution and abundance track these landscape patterns such that at low elevations, animals are distributed in their highest abundance near stream sides but become less dependent on stream-side habitat at high elevations due to the regionally cool and moist habitat. Salamander life history also varies across these gradients; survival decreases with elevation but reproductive rates and growth increase with elevation. Both survival and reproduction decrease with stream distance at low elevations, but growth and movement increase with stream distance. I also found that a metric for stress, dermal Corticosterone, (dCORT) was lowest in animals at low elevations and stream distance had no effect. Salamander dCORT additively increased in response to experimental conditions reflective of future climate change. I also found that the surface activity probability of salamanders will likely increase in the future in response to rising temperatures. Using a highly integrative approach, my research collectively shows that salamanders have multi-faceted responses to spatial variation of landscapes and will be impacted by future climate change.

The Biology of Plethodontid Salamanders

The Biology of Plethodontid Salamanders
Author: Richard C. Bruce
Publisher: Springer
Total Pages: 485
Release: 2000-04-30
Genre: Science
ISBN: 9780306463044

This volume offers a state-of-the-art overview of plethodontid salamanders. Readers will find the best current understanding of many aspects of the evolution, systematics, development, morphology, life history, ecology, and field methodology of these animals.

Genetic Structure Due to Variation in Breeding Time in a Salamander Population

Genetic Structure Due to Variation in Breeding Time in a Salamander Population
Author: Scott A. Thomas
Publisher:
Total Pages: 28
Release: 2013
Genre: Biology
ISBN:

The fine-scale genetic structure of populations is traditionally thought to be shaped primarily by geographic barriers to reproduction among local populations. However, other mechanisms of isolation have been recognized, but little has been done to determine their relative roles in shaping genetic variation in natural populations. In this study, I test whether genetic structure within and among breeding ponds of spotted salamanders (Ambystoma maculatum) is influenced by within-pond variation in breeding time. I found significant genetic structure attributable to variation in breeding time within ponds. This temporal structure was not consistent across ponds, indicating it is a local and not a regional effect. However, this temporal structure did not fully resolve strong patterns of inbreeding within ponds, indicating that reproductive barriers operating with in ponds are more effective than either spatial or phenological ones. Together, these findings reveal complex relationships between genetic structure and variation in breeding phenology that would not be uncovered by spatial or temporal analyses alone.

Assessing the Relative Influence of Abiotic and Biotic Impacts to Range Limits in Two Terrestrial Salamander Species (Plethodon Glutinosus and Plethodon Mississippi).

Assessing the Relative Influence of Abiotic and Biotic Impacts to Range Limits in Two Terrestrial Salamander Species (Plethodon Glutinosus and Plethodon Mississippi).
Author: Heather Renee Cunningham
Publisher:
Total Pages: 166
Release: 2010
Genre: Electronic dissertations
ISBN:

My research investigated the impact of abiotic factors and species interactions on the geographic distribution of two terrestrial salamander species, Plethodon glutinosus(Northern Slimy Salamander) and P. mississippi (Mississippi Slimy Salamander) at different spatial scales. I addressed the influence of ecological factors such as climate and topography on the relative strength of competitive interactions at broad and local scales. Often these factors are studied as independent determinants of species range limits; therefore, my research was designed to address how interactions between different ecological factors affected populations across geographic space. The novelty of my research was the methodological approach used. To my knowledge, this is the first use of ecological niche modeling in conjunction with fine scaled studies of competitive interactions to empirically test the influence of ecological factors on the relative strength of competitive interactions. At broad spatial scales the cost of competitive interactions for P. glutinosus and P. mississippiwas found to increase at the range margin relative to the interior of the range. However, along the range margin, the influence of climate and species interactions did not vary in a predictable manner. It is likely that interactions between microclimatic conditions, habitat structure, and land cover are stronger constraints on species interactions at the range margin than broad scale climate patterns. Subtle alterations in aggressive behavior, due to the introduction of a non-native congener, had little impact in local scale distribution. This is likely due to habitat structure and local abiotic conditions at the site of introduction. Overall the distributions of P. glutinosus and P. mississippi are shaped by multiple interactions between abiotic and biotic factors that differ in their relative strength at different spatial scales across geographic space. My work demonstrates the importance of considering interactions among various ecological causes of range limits and the spatial scale of investigation.

Reptile Biodiversity

Reptile Biodiversity
Author: Roy W. McDiarmid
Publisher: Univ of California Press
Total Pages: 424
Release: 2012-01-10
Genre: Nature
ISBN: 0520266714

“Authoritative and comprehensive—provides an up-to-date description of the tool box of methods for inventorying and monitoring the diverse spectrum of reptiles. All biodiversity scientists will want to have it during project planning and as study progresses. A must for field biologists, conservation planners, and biodiversity managers.”—Jay M. Savage, San Diego State University “Kudos to the editors and contributors to this book. From the perspective of a non-ecologist such as myself, who only occasionally needs to intensively sample a particular site or habitat, the quality and clarity of this book has been well worth the wait.”—Jack W. Sites, Jr.

Amphibian Declines

Amphibian Declines
Author: Michael J. Lannoo
Publisher: Univ of California Press
Total Pages: 1124
Release: 2005-06-15
Genre: Nature
ISBN: 9780520235922

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.

Wildlife Habitat Management

Wildlife Habitat Management
Author: Brenda C. McComb
Publisher: CRC Press
Total Pages: 338
Release: 2007-06-20
Genre: Nature
ISBN: 1420007637

In recent years, conflicts between ecological conservation and economic growth forced a reassessment of the motivations and goals of wildlife and forestry management. Focus shifted from game and commodity management to biodiversity conservation and ecological forestry. Previously separate fields such as forestry, biology, botany, and zoology merged

Herpetology

Herpetology
Author: Laurie J. Vitt
Publisher: Academic Press
Total Pages: 544
Release: 2012-12-02
Genre: Science
ISBN: 0323139248

Herpetology has always been one of the most exciting disciplines of zoology. During the past few years the field has continued to grow, yet it has been plagued by scarcity of comprehensive, up-to-date textbooks containing the most important developments. This timely book fills that void. Through skillful synthesis, the author summarizes the diversity in the biology of living amphibians and reptiles and describes the breadth of current herpetological research. Topics covered include the evolution, classification, development, reproduction, population, and environmental issues surrounding the study of amphibians and reptiles. Designed as an advanced undergraduate textbook, Herpetology is a valuable resource for students, practitioners, and interested amateurs alike. - Provides an incisive survey and much needed update of the field - Emphasizes the biological diversity among amphibians and reptiles - Details the most recent research findings, citing ke