SESSION B:

Title: A Dual-scale Approach to Conservation Planning for Vernal Pools: Regional Threat Analysis and Local mapping of Critical Habitat Elements

Authors: Robert Baldwin¹, Phillip deMaynadier², Aram JK Calhoun^3
1Department of Plant, Soil and Environmental Sciences, University of Maine, Orono, Maine. (207) 581-2821. rob_baldwin@umenfa.maine.edu
²Herptile and Invertebrate Group, Maine Department of Inland Fisheries and Wildlife, Bangor, ME. (207) 941-4239. phillip.demayandier@maine.gov
³Department of Plant, Soil and Environmental Sciences, University of Maine, Orono, Maine. (207) 581-3010. calhoun@maine.edu

Abstract:

Most pool-breeding amphibians utilize a mosaic of neighboring aquatic and terrestrial habitats, increasingly threatened in urbanizing Maine. To conserve vernal pool fauna, spatial tools are needed to (1) assess future threat from development pressure at the regional scale, and (2) design cost-effective habitat conservation plans at the local scale. We developed a threat analysis for pool-breeding amphibian habitat that focuses conservation attention where development pressure intersects with high-value habitat. Our results suggest that 1.5% of the southern Maine landscape is acutely threatened for pool-breeding amphibians, and nearly 50% of the region is in elevated threat status. While vernal pool conservation opportunities exist in the region’s remaining large forested blocks, high land values make acquisition too costly. High costs can be mitigated by applying a priority-based conservation planning approach that maps and protects high value vernal pools and selected neighboring habitats. We provide an example of such an approach for wood frogs (Rana sylvatica) using movement and habitat selection data informed by radio telemetry. Wood frogs showed a seasonal pattern of movement away from breeding pools to neighboring forested wetlands (max. recorded overland migration = 340 m), where summer activity was concentrated in shaded, moist terrestrial microhabitats. Our site-based plan incorporates this network of discrete but migration-connected habitat elements (e.g., breeding pools, upland forest, nearby forested wetlands), and when applied to the study area, reduced the amount of land requiring direct protection by 25 to 30% from that of traditional core habitat models. With the rapid dissemination of GIS technology, a spatial planning approach for pool-breeding fauna is increasingly feasible.