Download or read book Regional Population Structure of Spotted Salamanders Ambystoma Maculatum in a Fragmented Landscape written by Jennifer Lyn Purrenhage and published by . This book was released on 2004 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Multiple scale Analysis of the Effects of Landscape Structure on Populations of Yellow spotted Salamanders Ambystoma Maculatum written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Multiple scale Analysis of the Effects of Landscape Structure on Populations of Yellow spotted Salamanders Ambystoma Maculatum written by Samara T. Eaton and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I examine the effects of landscape structure on the incidence and abundance of yellow-spotted salamanders, Ambystoma maculatum, and use these population level responses as indirect measures of movement. Two surveys of breeding populations in ponds located in a heterogeneous landscape were conducted and effects of landscape structure assessed at multiple spatial scales. Landscape structure was quantified as the proportion of forest and the total length of roads surrounding ponds. Additionally, the movement capabilities of juvenile A. maculatum in different habitat types was explored. Through the first survey I show that the proportion of forest influences incidence and density at a small spatial scale (100 m). I conclude that the breeding and post-breeding migration movements are influenced by the amount of forest and identify 15% forest, within 100 m of the pond, as a threshold amount of forest below which A. maculatum cannot persist at a pond. Results from a second survey, which encompassed a greater number of ponds at broader spatial scales, concur with the previous survey for the small scale effects of the proportion of forest, however, there is a significant effect of the proportion of forest at a broad spatial scale (1000 m). This provides indication that populations are spatially structured and that the amount of forest increases the connectivity of the landscape for A. maculatum. Also, at small spatial scales the total amount of road has a negative effect on incidence and abundance. Experimentally I assess the rates of movement of juveniles in forested and field habitat. Results show that juveniles can move faster in field habitat than forest. Finally, I explore the possibilities of harmonic radar as a new technique for tracking juvenile A. maculatum.
Download or read book Use of Microsatellites to Determine the Effective Population Size of a Local Population of Spotted Salamanders Ambystoma Maculatum written by Caroline G. Letourneau and published by . This book was released on 2011 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The spotted salamander (Ambystoma maculatum) is an aggregate breeding amphibian that is dependent upon vernal pools for its reproductive life cycle. However, as wetland habitats become increasingly fragmented as the result of human activity, populations of A. maculatum may become progressively isolated from one another. Such isolation can impact the genetic variation of a population and thus pose challenges to its long term survival. This study used nine microsatellite loci to determine the levels of heterozygosity and the effective population size (Ne) of a population of spotted salamanders (Ambystoma maculatum) located at Wheaton College in Norton, Massachusetts. The mean observed heterozygosity was calculated as 0.59, which is similar to estimates of other A. maculatum populations, and Ne was estimated between 42 and 60 individuals. These values suggest that the Wheaton College vernal pool population of A. maculatum is genetically stable in the short term.
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.
Download or read book Genetic Structure Due to Variation in Breeding Time in a Salamander Population written by Scott A. Thomas and published by . This book was released on 2013 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Breeding Pond Fidelity Population Structure and Phylogeography in the Spotted Salamander Ambystoma Maculation written by Christopher A. Phillips and published by . This book was released on 1989 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Demography Migration and Metapopulation Structure of Pond Breeding Salamanders written by Peter Cornell Jr Trenham and published by . This book was released on 1998 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Landscape level Population Structure and Local Variability in Marbled Salamanders Ambystoma Opacum of Western Massachusetts written by Lloyd R. Gamble and published by . This book was released on 2004 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Terrestrial Habitat Use by Radio implanted Spotted Salamanders Ambystoma Maculatum written by Ashley Lynn Nussbaum and published by . This book was released on 2005 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptation to Acidification in Spotted Salamanders Ambystoma Maculatum written by Nicholas Gervais and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Declines in amphibian populations have been noted since the late 1980's with many of the causes linked to habitat contamination and destruction by natural and anthropogenic sources. Amphibians with bi-phasic life histories have been thought to be particularly vulnerable to negative environmental conditions but there is much evidence of their resilience and capacity to survive in degraded or contaminated environments. Larval amphibians in small permanent or ephemeral ponds may be particularly vulnerable to altered environmental conditions and may face the greatest pressure to adapt. In Chapter 1, I briefly review the evidence of amphibian declines and how populations may adapt to and overcome assorted negative environmental factors. In Chapter 2, I investigated the phenomenon of adaptation in a particular circumstance. I collected Spotted Salamander (Ambystoma maculatum) egg masses from a population breeding in a naturally acidic pond called Bat Lake, as well as four other populations living in lakes closer to pH neutral. To determine if the salamanders were adapted to their particular breeding lakes, I used common garden experiments in the lab where I raised larvae from each of the lakes in the waters from all the other lakes, as well as their own and compared the survival rates, size at metamorphosis and time to metamorphosis. Bat Lake larvae grew larger and survived longer in their acidic native breeding pond water than in the waters of other lakes suggesting they are adapted to their native pond waters. The larvae from the other lake populations showed similar results and fared better in their native waters than in the Bat Lake water. Based on these results, in Chapter 3, I tested if pH, specifically, was causal. I raised larvae from the five populations in waters of different pH (4.0, 5.5, 7.0), reasoning that if the Bat Lake population was more adapted to the high acidity compared to the other populations, the larvae from Bat Lake should demonstrate higher fitness correlates at lower pH than larvae of other populations. In this experiment, the Bat Lake larvae survived longer and grew larger in the highly acidic water than did larvae from the other populations. My results are consistent with natural selection for tolerance of low pH conditions tolerance among Bat Lake Spotted Salamander larvae and indicate that the salamanders from Bat Lake potentially exhibit signs of local adaption to the highly acidic conditions in which they live. This study was unable, however to prove whether this adaptation was due to evolutionary change, phenotypic plasticity, maternal effects or some other unknown factor. " --
Download or read book The Population Biology of the Spotted Salamander Ambystoma Maculatum Inhabiting Penn State Erie Wetlands written by Pamela Silver and published by . This book was released on 1999 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Journal of Zoology written by and published by . This book was released on 2006 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Amphibian Declines written by Michael Lannoo and published by Univ of California Press. This book was released on 2005-06-15 with total page 1117 pages. Available in PDF, EPUB and Kindle. Book excerpt: This benchmark volume 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. Horror stories on this topic have been featured in the scientific and popular press over the past fifteen years, invariably asking what amphibian declines are telling us about the state of the environment. Are declines harbingers of devastated ecosystems or simply weird reflections of a peculiar amphibian world? This compendium—presenting new data, reviews of current literature, and comprehensive species accounts—reinforces what scientists have begun to suspect, that amphibians are a lens through which the state of the environment can be viewed more clearly. And, that the view is alarming and presages serious concerns for all life, including that of our own species. The first part of this work consists of more than fifty essays covering topics from the causes of declines to conservation, surveys and monitoring, and education. The second part consists of species accounts describing the life history and natural history of every known amphibian species in the United States.
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 Microsatellites written by David B. Goldstein and published by Oxford University Press on Demand. This book was released on 1999 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microsatellites are short stretches of repeated DNA, found in most genomes, that show exceptional variability in humans and most other species. This variability has made microsatellites the genetic marker of choice for most applications, including genetic mapping and studies of the evolutionary connections between species and populations. This book brings together an international group of scientists currently working in microsatellites. Their contributions provide a detailed descriptionof microsatellite biology, focusing on their mutation properties, generation, decay, and possible functional roles. They introduce the theoretical models that underpin the most popular methods for analysing the information that microsatellites can yield, including methods for estimating coalescent times, population divergences, and migration. Finally, the book describes the various ways in which the potential of microsatellites is being harnessed in a range of applications including medical genetics, forensics, genetic mapping, the analysis of human evolution, and conservation genetics.
Download or read book Environmental Impacts of Wind Energy Projects written by National Research Council and published by National Academies Press. This book was released on 2007-09-27 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: The generation of electricity by wind energy has the potential to reduce environmental impacts caused by the use of fossil fuels. Although the use of wind energy to generate electricity is increasing rapidly in the United States, government guidance to help communities and developers evaluate and plan proposed wind-energy projects is lacking. Environmental Impacts of Wind-Energy Projects offers an analysis of the environmental benefits and drawbacks of wind energy, along with an evaluation guide to aid decision-making about projects. It includes a case study of the mid-Atlantic highlands, a mountainous area that spans parts of West Virginia, Virginia, Maryland, and Pennsylvania. This book will inform policy makers at the federal, state, and local levels.
