Evaluating the Impacts of Climate Extremes on Karst Hydrology and Species Vulnerability

Karst aquifers—formed when the movement of water dissolves bedrock—are critical groundwater resources in North America. Water moving through these aquifers carves out magnificent caves, sinkholes, and other formations. These formations are home to high concentrations of rare and endangered species, but the hydrological conditions that support these species can change rapidly. Managing these ecosystems into the future requires a better understanding of how climate, hydrology, and karst ecosystems interact.

The objective of this project was to determine how species and ecosystems associated with karst might respond to future temperature and precipitation extremes and accompanying changes in groundwater levels and springflow. The research focused on 16 species in the Edwards aquifer in south-central Texas and eight species in the Madison aquifer in western South Dakota. Researchers linked global climate models, regional climate models, and hydrologic models to determine how future springflow might be impacted by changes in temperature and precipitation. By combining information about future hydrology with what we know about species needs, researchers determined the vulnerability of the selected species to climate extremes.

Researchers found that more species in the Edwards aquifer are vulnerable to climate extremes than in the Madison aquifer, due in part to the more severe hydrologic changes that the Edwards aquifer is expected to undergo. This result suggests that including hydrologic factors critical to species health is essential in evaluating the vulnerability of karst ecosystems to climate extremes. Natural resource managers can use this information to understand how the character of karst systems are changing and prioritize conservation activities accordingly.