Seasonal snowpack characteristics influence soil temperature and water content at multiple scales in interior western U.S. mountain ecosystems

Abstract

Abstract Mountain snowpacks directly and indirectly influence soil temperature (T soil ) and soil water content (θ). Vegetation, soil organisms, and associated biogeochemical processes certainly respond to snowpack‐related variability in the soil biophysical environment, but there is currently a poor understanding of how snow‐soil interactions vary in time and across the mountain landscape. Using data from a network of automated snowpack monitoring stations in the interior western U.S., we quantified seasonal and landscape patterns in T soil and θ, and their dependence on snowpack characteristics over an eleven year period. Elevation gradients in T soil were absent beneath winter snowpacks, despite large gradients in air temperature (T air ). Winter T soil was warmer and less variable than T air, but interannual and across‐site variations in T soil were likely large enough to impact biogeochemical processes. Winter θ varied between years and across sites, but during a given winter at a site it changed little between the start of snowpack accumulation and the initiation of spring snowmelt. Winter T soil and θ were both higher when early winter snow accumulation was greater. Summer θ was lower when summer T air was high. Depending on the site and the year examined, summer θ was higher when there was greater summer precipitation, a larger snowpack, later snowpack melt, or a combination of these factors. We found that snowpack‐related variability in the soil environment was of sufficient magnitude to influence biogeochemical processes in snow‐dominated ecosystems.