Understanding Plant Water Use Across the Snow-Rain Transition
Faculty Mentor Information
Dr. Sarah Godsey
Presentation Date
7-2017
Abstract
Shifts in the elevation of the snow-rain transition are likely with a warming climate and may affect soil water availability and patterns of transpiration by plants that depend on soil moisture. Understanding current water use by plants will help to predict what may happen if the snow-rain transition shifts. Previous research across the rain-snow transition in the Pioneer Creek watershed in central Idaho focused on patterns of plant water use, but observed soil moisture quantities were difficult to interpret. This data has been reinterpreted after extensive soil moisture probe calibration to three sites at different elevations. Calibration included packing down the dry soil to field bulk densities and comparing gravimetric with probe measurements at five or more samples across a moisture gradient for each site. Seasonal patterns of soil moisture from areas with snow and rain were corrected and compared to sap flow in Douglas Fir. Sporadic rainfall events that led to increased soil moisture appear to minimize differences in snowmelt timing and plant water use across the elevation gradient in the Pioneer watershed.
Understanding Plant Water Use Across the Snow-Rain Transition
Shifts in the elevation of the snow-rain transition are likely with a warming climate and may affect soil water availability and patterns of transpiration by plants that depend on soil moisture. Understanding current water use by plants will help to predict what may happen if the snow-rain transition shifts. Previous research across the rain-snow transition in the Pioneer Creek watershed in central Idaho focused on patterns of plant water use, but observed soil moisture quantities were difficult to interpret. This data has been reinterpreted after extensive soil moisture probe calibration to three sites at different elevations. Calibration included packing down the dry soil to field bulk densities and comparing gravimetric with probe measurements at five or more samples across a moisture gradient for each site. Seasonal patterns of soil moisture from areas with snow and rain were corrected and compared to sap flow in Douglas Fir. Sporadic rainfall events that led to increased soil moisture appear to minimize differences in snowmelt timing and plant water use across the elevation gradient in the Pioneer watershed.