Fremont cottonwoods are fundamental species of riparian habitats across the southwestern United States, providing soil and water temperature regulation, nutrients for other vegetation and insects, and critical wildlife habitat. Stressors like changing climate and streamflow diversion are impacting Fremont cottonwood forests across the southwestern United States, but there is poor understanding of how these impacts vary across landscapes. 

Sources/Usage: Some content may have restrictions. View Media Details

In this study, researchers investigated the effects of streamflow, water availability and temperature on cottonwoods along the Yampa and Green Rivers. To do this, they measured cottonwood growth along a streamflow and climate gradient. In sites with highest hydrologic stress — less stream flow, lower water availability, and higher temperatures — trees were shorter and in poorer condition, supporting other findings that streamflow and climate influence forest change. As drought continues to threaten the southwest, resource managers can use these results to identify which sites are most vulnerable to forest loss, and determine locations where potential loss may be mitigated through streamflow management.