Abstract (from Ecosphere): In semi‐arid mountainous regions across the western United States, the distribution of upland aspen (Populus tremuloides) is often related to heterogeneous soil moisture subsidies resulting from redistributed snow. As temperatures increase, interactions between decreasing snowpack and future trends in the net primary productivity (NPP) of aspen forests remain uncertain. This study characterizes the importance of heterogeneously distributed snow water to aspen communities in the Reynolds Creek Critical Zone Observatory located in southwestern Idaho, USA. Net primary productivity of three aspen stands was simulated at sites spanning elevational and precipitation gradients using the biogeochemical process model [...]