The effect of whitebark pine forests on snowpack and streamflow
Forests influence regional hydrology by influencing snow accumulation and melt, the partitioning of precipitation into runoff and transpiration, and therefore the timing, quality, and quantity of available water for downstream ecosystems. High-elevation tree species such as whitebark pine (Pinus albicaulis) may have a disproportionate effect on the water cycle and water storage because they grow at the highest forest elevations where snowfall is greatest. However, warming temperatures have led to reduced snowpack levels, increased drought and wildfire frequency, increased outbreaks of forest insects and pathogens, and elevated forest mortality. Whitebark pine’s effect on hydrological processes, particularly snowpack and streamflow, remains poorly understood, limiting our ability to predict the impacts of future climate-related disturbance on watershed hydrology and ecosystems. This study therefore investigates how whitebark pine forests affect snowpack accumulation and loss and streamflow timing, quality, and quantity. We hypothesize that whitebark pine forests protect snowpack, increase snow retention, and slow snowmelt and runoff, thereby prolonging streamflow later into the growing season. Delayed snowmelt is likely to affect stream water quality through the maintenance of lower water temperatures, higher levels of dissolved oxygen (DO), and lower specific (ionic) conductance longer into the growing season.
Dr. Danielle Ulrich and Dr. Brian Smithers are assistant professors in the Department of Ecology at Montana State University. Dr. Ulrich’s research and teaching interests include plant physiological ecology, plant responses to environmental stress, and climate change. Dr. Smithers’ research and teaching interests include forest and plant ecophysiology and sub-alpine forest and alpine community ecology.