Life on the Edge:
Managing Peripheral Populations in a Changing Landscape

THOMAS B. HERMAN

Centre for Wildlife and Conservation Biology, Acadia University,
Wolfville, Nova Scotia B0P 1X0, Canada / e-mail: tom.herman@acadiau.ca

        ABSTRACT:  In Nova Scotia all four resident turtle species (Chelydra serpentina, Clemmys insculpta, Emydoidea blandingii, and Chrysemys picta) closely approach the northern limits of their geographic ranges.  Two, E. blandingii and C. insculpta, are restricted in their distribution and are probably vulnerable to environmental changes associated with global warming and habitat fragmentation.  Both are long-lived species with apparently strong site affinities.  However, in Nova Scotia E. blandingii exists almost entirely within a protected landscape (Kejimkujik National Park), while C. insculpta occurs in scattered populations primarily within working landscapes (mostly managed forests and mixed agriculture).  We are developing species-level and ecosystem-level management strategies for these two species, which recognize the differences in scale, jurisdiction, and intensity of management.  Peripheral populations are often presumed to contain the adaptive solutions to problems posed by environmental change.  However, depending on the speed and scale of that change, these same populations may also be highly vulnerable.