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Limits to Species’ Distribution and Persistence: A Landscape Genetics Study of Two Amphibian Species in Yellowstone National ParkEPA Grant Number: F6F21367
Title: Limits to Species’ Distribution and Persistence: A Landscape Genetics Study of Two Amphibian Species in Yellowstone National Park
Investigators: Murphy, Melanie
Institution: Washington State University
EPA Project Officer: Jones, Brandon
Project Period: September 1, 2006 through September 1, 2009
Project Amount: $111,344
RFA: STAR Graduate Fellowships (2006) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Ecological Indicators/Assessment/Restoration , Fellowship - Terrestrial Systems Ecology
My objective is to test how landscape features influence species’ dispersal, species’ distributions, and population persistence. I will address the following questions using the boreal toad (patchy distribution, declining) and boreal chorus frog (continuous distribution, abundant) in Yellowstone National Park:
- What anthropogenic and ecological landscape features limit gene flow in anurans?
- Why do some species have more restricted distributions than others?
- Are amphibians declining in protected areas?
A central objective of conservation biology is to understand processes that shape species’ distributions and population persistence. The emerging discipline of landscape genetics provides a conceptual framework to address these processes, through an integration of landscape ecology, spatial statistics, and population genetics. A landscape genetics approach is ideal for modeling amphibian systems because amphibians generally have population genetic structure on appropriate geographic scales and are sensitive to landscape characteristics, including land use change.
In my preliminary research, I developed a unique method to represent gene flow as a continuous spatial response variable. This method newly enables analysis of the influence of continuous (e.g., elevation, moisture), as well as discrete (e.g., roads, land cover), landscape variables on gene flow. I will implement this methodology to create landscape genetic models of gene flow for the two study species and to determine the landscape variables that explain patchy vs. continuous distributions. Finally, I will test for genetic signatures of recent population declines. If population declines are detected; I will model population status (decline vs. no decline) based on landscape variables and presence of a chytrid fungus (B. dendrobatidis), a pathogen implicated in the global decline of amphibians.
I predict that gene flow in P. maculata will be more limited than B. boreas due to smaller empirically-estimated dispersal distances, and influenced by habitat connectivity and moisture. I also predict that B. boreas is in decline through at least part of its range due to presenceof chytrid fungus (B. dendrobatidis).