Dissertation
New approaches in landscape genetics and niche modeling for understanding limits to anuran distributions
Washington State University
Doctor of Philosophy (PhD), Washington State University
08/2008
DOI:
https://doi.org/10.7273/000005875
Abstract
A central objective in ecology and conservation biology is to understand processes
limiting species’ distributions and population connectivity. This is particularly important for
amphibians, which are in global decline at rate exceeding other vertebrates. Niche modeling and
landscape genetics are well suited for addressing distribution and connectivity respectively. This
dissertation addresses four objectives: i) test whether landscape genetics is possible on spatial
and temporal scales relevant to conservation, ii) examine whether spatial processes,
environmental condition or dispersal limited niche best explains the observed differences in
Pseudacaris maculata and Bufo boreas distributions in Yellowstone, iii) test alternative
hypotheses of ecological processes driving B. boreas connectivity in Yellowstone, and iv)
develop a new application of gravity models to estimate metapopulation connectivity for Rana
luteiventris in central Idaho. In Chapter 1, I developed and evaluated “genetic surfacing”, a
continuous method for representing multilocus genetic variation. I detected landscape genetic
structure on a contemporary time scale relevant to conservation questions (5 generations post
v
vicariance, migration probability 0.10), even when population differentiation was minimal (FST
0.00015). Using spatial distribution models in Chapter 2, I found environmental conditions
limiting species’ distributions to be divergent and distance limited niche theory best explained
observed species’ distributions. In Chapter 3, I implemented a novel algorithmic approach to
test alternative hypotheses of processes limiting connectivity in B. boreas. At fine scales,
connectivity was limited by cover, precipitation and roads, whereas ridges, temperature, and
precipitation limited connectivity at a broad scale. Using newly derived gravity models in
Chapter 4, I found R. luteiventris connectivity was a function of both at site and between site
landscape processes. Primary productivity and fish presence at sites limited production of
potential migrants. Temperature and major topographic complexity between sites limited
connectivity. The impact of temperature-moisture regimes on all three species suggests that
future climate change may have a dramatic impact on anuran distribution and connectivity. The
methods developed in this dissertation could be used to predict species’ distributions (niche
models) and resulting connectivity (landscape genetics) in future landscapes.
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Details
- Title
- New approaches in landscape genetics and niche modeling for understanding limits to anuran distributions
- Creators
- Melanie April Murphy
- Contributors
- Andrew T. Storfer (Chair)R Dezzani (Committee Member)Charles E. Peterson (Committee Member)Michael S Webster (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- School of Biological Sciences
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 252
- Identifiers
- 99901055034601842
- Language
- English
- Resource Type
- Dissertation