Water Resources Research Act Program

Details for Project ID 2014MT290B

Student Fellowship: Precipitation and topographic controls over montane forest transpiration

Institute: Montana
Year Established: 2014 Start Date: 2014-03-01 End Date: 2015-02-28
Total Federal Funds: $2,000 Total Non-Federal Funds: $880

Principal Investigators: Justin Martin

Project Summary: Studies from Montana and the surrounding region have observed decadal trends in snowpack declines characterized by increasing spring temperatures and declining snowpack depths as spring snows transition to rain. It is important to be able to estimate the volume of water stored in upland catchments and the timing of its release in order to allocate water for agricultural use, adequate river and stream flows, and urban demands. Currently, our ability to predict available water from infiltration of mountain snows is hindered by a limited understanding of the partitioning of this water into recharge and evapotranspiration. The timing and magnitude of water inputs from snow are expected to change with projected climate warming, altering the dynamics of montane ecosystems that shape hydrologic processes. Project objectives are to determine if 1) the proportion of transpired water attributable to rain/snow differ by tree species depending on the species ability to use water from snowmelt vs. summer rains; 2) the proportion of transpired water attributable to rain/snow differ by topographic position depending on the differential behavior of these source waters after infiltration; and 3) field based and remotely sensed estimates of biomass, stand composition, and topography can be used to scale tree level measurements of transpiration and the spatial and temporal distribution of its source waters to the watershed level.