Long-term alpine stream monitoring in the Teton Range: Investigating multi-year patterns and thermal physiology

Abstract

Alpine streams and the biotic communities they contain are imperiled worldwide due to climate warming and the rapid decline of ice. The loss of glaciers and permanent snowpack may drive local populations to extinction, especially organisms with narrow habitat tolerances. We have been monitoring alpine streams in the Teton Range since 2015 that originate from three hydrological sources: surface glaciers, snowfields, or subterranean ice (e.g., rock glaciers). We call these stream types glacier-fed, snowmelt-fed, and icy seeps, respectively. We hypothesize that icy seeps may persist on the landscape longer than other hydrologic sources and that these features may act as a refuge for cold-adapted organisms such as the stoneflies Zapada glacier and Lednia tetonica. In November 2019, Z. glacier and a sister species of L. tetonica, Lednia tumana, were listed under the U.S. Endangered Species Act. This decision was based in part on work funded by the UW-NPS and highlights the pressing nature of our efforts. In 2019, we collected a 5th year of long-term data to begin investigating multi-year signals in the data. Our second 2019 objective was to further explore how thermal regimes affect tolerance of potentially imperiled insects. Because our annual data collection occurs in late summer with sample processing and analysis extending into the following year, this report will be a broad update on the project as whole, rather than 2019-specific. Through long-term monitoring of streams from different hydrological sources, we are building a dataset that will allow us to understand changes as air temperatures warm and permanent ice is lost in the alpine zone.

Featured photo by Nicole Y-C on Unsplash. https://unsplash.com/photos/9XixVlnUCbk