Objective

Metapopulation theory has commonly been used to address conservation questions related to increasing loss or alteration of habitat and fragmentation that can jeopardize the persistence of species. Two processes are critical for effective metapopulation dynamics and species persistence. First, some local populations must exist in high-quality habitat "source" patches and produce surplus offspring frequently enough to balance losses in "sink" populations that occupy low-quality habitat. Second, connectivity among habitat patches on the landscape must be maintained to allow successful dispersal and rescue of sink patches or for colonization of new habitat patches. This second process is the result of species locomotor ability, distance between patches, and quality of the habitat between patches. Despite a clear understanding of the theoretical importance of source-sink dynamics, measurement of both these ecological processes in natural populations has seldom been achieved.

The objective of this project is to understand the impact of landscape heterogeneity on the source-sink dynamics of a species of management concern, the ringed salamander (Ambystoma annulatum), and its interactions with a co-occurring species, the spotted salamander (Ambystoma maculatum), at Fort Leonard Wood, Missouri. Specific objectives are to: (1) conduct occupancy and abundance analyses to clearly identify the prevalence of ringed and spotted salamanders across the landscape and environmental factors (abiotic and biotic) related to source and sink populations, (2) determine whether species interactions influence source-sink dynamics, (3) identify habitat features related to successful dispersal and connectivity among populations, and (4) develop and apply connectivity models based on circuit and graph theory that are effective for conservation and restoration management of ringed salamanders.