Vol. 40 (2017)
Research Project Ecology

Establishing a long-term monitoring network for assessing potential climatic refugia in cold alpine streams

Lusha Tronstad
Wyoming Natural Diversity Database, University of Wyoming, Laramie, WY
J. Joseph Giersch
U.S.G.S., Northern Rocky Mountain Science Center, Glacier National Park, West Glacier, MT
Scott Hotaling
School of Biological Sciences, Washington State University, Pullman, WA
Lydia Zeglin
Division of Biology, Kansas State University, Manhattan, KS
Oliver Wilmot
Wyoming Natural Diversity Database, University of Wyoming, Laramie, WY
Rebecca J. Bixby
Department of Biology, University of New Mexico, Albuquerque, NM
Debra S. Finn
Department of Biology, Missouri State University, Springfield, MO
Snowy texture
Published December 15, 2017

Abstract

Managing landscapes to maintain climate refugia is likely the best strategy to promote persistence of temperature-sensitive species with limited dispersal capacity. Rare, cold-stenothermic taxa occupy mosaic mountain stream networks due largely to hydrological source heterogeneity. We collected environmental and biological data from alpine streams in the Teton Range, Wyoming representing runoff from snowpack (N=3), glaciers (N=4) and subterranean ice (N=4), every summer from 2015-2017. We quantified differences in habitat among the streams according to a glaciality index that included bed stability, suspended solids, temperature and conductivity, and by comparing annual water temperature profiles for each stream. We measured to what degree macroinvertebrate and diatom assemblages varied by stream type. Abiotic and biotic characteristics appeared to differ among sources. Notably, streams fed by subterranean ice (icy seeps) maintained extremely low (mean <2°C) and stable water temperature. Rare, cold-stenothermic stonefly species (Zapada glacier and Lednia tetonica) were indicators for, although not exclusive to, icy seeps. Icy seeps and their sources may be refugia for temperature-sensitive taxa, as the subsurface ice is more insulated from warmer air temperatures.

 

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