Other Projects
Population Dynamics at Mount St. Helens, WA
The
change in spatial distributions of species is a critical issue as landscape and
climate changes loom. However, complete, well-collected timeseries data is
often unavailable to ask questions about the dynamics of populations in natural
systems. Further, information on the dispersal capabilities of organisms is
important to understand changes in distribution, but is lacking for many
species. Amphibians are presumed to be sensitive to habitat change, and in
general have limited dispersal ability when compared to larger-bodied animals.
Since 1980, when Mount St. Helens (Washington State) erupted, Charlie
Chrisafulli of the US Forest Service has been monitoring amphibians at over 100
ponds in the National Monument area. These data offer a unique opportunity to
ask questions about occupancy, dispersal, and community assembly of amphibians.
We are investigating the spatial turnover, colonization, and extinction
dynamics, using methods which allow incorporation of detection biases.
Managing Habitat for Amphibians
Monitoring programs worldwide focus on estimation of trends in populations, often with an implicit expectation that identification of a trend will result in smart decisions as to how to respond (via management). Though many researchers investigating the patterns and causes of amphibian declines have focused on estimation and detection of population trends, we take a different approach. In two ongoing projects (funded by the USGS Amphibian Research and Monitoring Initiative and the National Park Monitoring Program), we are linking amphibian monitoring data directly to potential management actions by following a structured approach to decision making. These projects involve working closely with biologists from USGS and academic institutions, resource managers from FWS and the NPS, and other stakeholders, including The Nature Conservancy. Notably, these collaborations will result in better-informed management, elucidate the links between local and regional stressors and amphibian population response, and provide more robust inference for amphibian population change throughout the northeastern United States.