H42C-06
Climate, karst, and critters—A multidisciplinary evaluation of karst species vulnerability to climate change
Thursday, 17 December 2015: 11:35
3018 (Moscone West)
Barbara J Mahler, U.S. Geological Survey, Austin, TX, United States, MaryLynn Musgrove, USGS Texas Water Science Center, Austin, TX, United States, Andrew J Long, U.S. Geological Survey, Washington Water Science Center, Tacoma, WA, United States, John F Stamm, USGS Florida Water Science Center Lutz, Lutz, FL, United States, Mary F. Poteet, University of Texas at Austin, Austin, TX, United States and Amy Symstad, USGS, Northern Prairie Wildlife Research Center, Jamestown, ND, United States
Abstract:
The complex hydrologic regimes of karst aquifers respond rapidly to the effects of climate change, and unique biological communities associated with karst are sensitive to hydrologic changes. To explore how climate change might affect karst-dependent species, we coupled a climate-change model, a hydrologic model, and a vulnerability assessment tool to evaluate projected hydrologic change and vulnerability of selected species at sites in the karstic Edwards aquifer (Texas) and Madison aquifer (South Dakota). The Advanced Research Weather and Research Forecasting (WRF) model was used to simulate projected climate from 2011 to 2050 at a 36-km grid spacing for 3 weather stations near the study sites. Daily climate projections from the WRF model were used as input for the hydrologic Rainfall-Response Aquifer and Watershed Flow (RRAWFLOW) model and the Climate Change Vulnerability Index (CCVI). RRAWFLOW is a lumped-parameter model that simulates hydrologic response at a single site, superposing the quick- and slow-flow responses that commonly characterize karst aquifers. CCVI uses historical and projected climate and hydrologic metrics to assess the vulnerability of a species. An upward trend in temperature was projected at all three weather stations; there was a trend (downward) in precipitation only for the Texas weather station. A downward trend in mean annual spring flow or groundwater level was projected for the three Edwards sites, but there was no significant trend for the two Madison sites. Of 16 Edwards aquifer species evaluated, 10 were scored as highly or moderately vulnerable under the projected climate change scenario. In contrast, all 8 Madison aquifer species evaluated were scored as moderately vulnerable, stable, or intermediate between the two. The inclusion of hydrologic projections in the vulnerability assessment was essential for interpreting the effects of climate change on aquatic species of conservation concern such as endemic salamanders.
