US-IALE 2018 has ended

Monday, April 9 • 5:30pm - 7:00pm
POSTER: Effects of Changing Precipitation on Connectivity in an Amphibian System with Environmentally-Responsive Dispersal Movements

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AUTHORS: Evan M. Bredeweg*, Nathan H. Schumaker, Tiffany S. Garcia – Oregon State University; Anita T. Morzillo, University of Connecticut

ABSTRACT: Amphibian species exhibit metapopulation qualities as they have diverse lifetime habitat needs that are segregated throughout a landscape. Factors that influence dispersal between these isolated habitats are of conservation concern, particularly as climate change may influence precipitation and, therefore, availability of aquatic habitat components. Our objective was to build a spatially explicit individual-based model using the HexSim simulator to investigate the impact of varying precipitation on the dispersal of recently metamorphosed amphibians. We used a generic amphibian species from the Pacific Northwest to develop the life history and biology parameters for this simulation. Twenty landscapes were built using randomly placed uniform habitat patches. Daily rainfall was simulated using probabilities built from monthly precipitation rates during the late summer and early fall (July-Nov) when most juvenile amphibians metamorphose and transition to terrestrial habitats. Simulated amphibians that were available to disperse assessed current conditions to make choices on when and how to disperse. Our model also compared functional connectivity of scenarios in two treatment groups of precipitation: current conditions and future projected conditions (year 2070, downscaled global model from CMIP5 using RCP 8.5 emissions scenario). Model runs were repeated 100 times for each generated landscape under each precipitation treatment. Under the projected precipitation treatment, overall rates of dispersal between populations decreased but average distance of successful dispersal movements increased. This mechanism may serve to open limited connectivity between some populations in the future. These results have important implications for the balancing of metapopulation dynamics of amphibian species and impact the priorities of future amphibian conservation planning.

Monday April 9, 2018 5:30pm - 7:00pm
Monroe Room

Attendees (5)