Mapping Climate Change Resistant Vernal Pools in the Northeastern U.S.

Abstract

Vernal pools of the northeastern United States are important breeding habitat for amphibians. These wetlands typically fill with water from autumn to early spring and dry by summer. Under projections of future climate, some pools may dry earlier than is typical, which in some cases could make it difficult for amphibians to complete metamorphosis successfully. This study evaluated the factors controlling vernal pool inundation (i.e., whether or not a pool has water in it) and generated model predictions of pool-inundation probability under a variety of weather and climate scenarios (e.g., dry, average, and wet weather, and future climate scenarios for the middle and end of the 21st century). Model predictions were used to identify possible hydrologic refugia, defined as pools that could continue to provide wetland habitat and support amphibian breeding under climate change. Using approximately 3,000 inundation observations from 450 pools located on protected areas across the Northeast, from West Virginia to Maine, models were developed linking pool-inundation patterns to various pool characteristics, such as pool-basin size and landcover of the area surrounding pool basins. Models also considered seasonal timing, short-term weather conditions, and long-term climate. Model predictions show the relative likelihood of pools being inundated under various weather and climate scenarios. Pools that show high probability of inundation late in the summer under future climate conditions and under the dry weather scenario could function as potential hydrologic refugia for amphibian breeding under climate change.