Dissertation
Integrating Niche Modeling and Landscape Genetics to Study Species' Responses to Climate Change: A Case Study of Rhyacotriton kezeri and R. variegatus
Doctor of Philosophy (PhD), Washington State University
01/2015
Handle:
https://hdl.handle.net/2376/112145
Abstract
Global climate change is expected to shift species' suitable habitat toward the poles over this century and beyond. Amphibians and other dispersal-limited taxa may be particularly vulnerable to the effects of climate change due to inability to track suitable habitat. Rhyacotriton kezeri and R. variegatus are two species of torrent salamanders with specific habitat needs and small geographic ranges. This dissertation had three objectives: 1) review and synthesize the results of recent studies of population genetic structure in amphibians, 2) characterize the level of genetic structure and identify landscape features correlated with genetic distance among populations of R. kezeri and R. variegatus, and 3) predict the future distributions of R. kezeri and R. variegatus with climate change through the integration of landscape resistance into range shift models. In Chapter 1, I reviewed 139 studies of amphibians published between 2001-2010 estimating genetic structure, and a meta-analysis revealed that conservation status was the only factor showing a significant relationship with genetic distance. In Chapter 2, I discerned high genetic structure among populations of R. variegatus. Models of landscape resistance revealed that high genetic structure was correlated with low stream and forest cover, high solar radiation, and short growing season. In Chapter 3, I expanded upon Chapter 2 to include R. kezeri and test additional variables, determining that despite subtle differences between species, forest cover, roads, streams, and a correlate of soil moisture best explained patterns of gene flow in both. Lower average genetic diversity in R. kezeri populations is likely due to greater habitat fragmentation. Finally, in Chapter 4, I predicted range shifts of R. kezeri and R. variegatus in response to climate change, incorporating habitat resistance based on the results of Chapter 3 to simulate movement from the current distributions into projected suitable habitat. Although range contraction is only expected for R. kezeri, simulations suggested that neither species would reach a large proportion of its potential range by 2070. Overall, this dissertation demonstrates the importance of understanding the constraints of habitat resistance on dispersal and its consequences for amphibian conservation in the contexts of habitat fragmentation and global climate change.
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Details
- Title
- Integrating Niche Modeling and Landscape Genetics to Study Species' Responses to Climate Change: A Case Study of Rhyacotriton kezeri and R. variegatus
- Creators
- Sarah L. Emel
- Contributors
- Andrew Storfer (Advisor)Jeremiah W Busch (Committee Member)Lisa A Shipley (Committee Member)Lisette P Waits (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Sciences, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 164
- Identifiers
- 99900581730601842
- Language
- English
- Resource Type
- Dissertation