Surface Energy Fluxes, Soil Moisture, and Evapotranspiration Across Three Ecosystems in a Semiarid Climate

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Understanding the land-atmosphere interaction at the ecosystem scale is important for water resource management and regional or global climate studies. Researchers examined surface fluxes of energy and moisture for three different ecosystems - sagebrush, cheatgrass, and lodgepole pine - in the Snake River Plain of Idaho. 

The study used three years of pooling data from USGS, University of Idaho, and Boise State University on eddy covariance, scintillometers, and modeling to evaluate biophysical processes that control the surface energy partitioning. Evapotranspiration was higher in lodgepole pine compared to cheatgrass and sagebrush, driven by higher leaf area index and summer precipitation. All three sites were water deficient and the residual amount of water percolating through and running off the soil was higher in lodgepole pine. Results indicate that sagebrush, cheatgrass, and lodgepole pine ecosystems in the Snake River Basin exhibit distinct surface energy partitioning due to heterogeneity in available energy, soil moisture conditions, and vegetation characteristics.

Valayamkunnath, P., Sridhar, V., Zhao, W., Allen, R.G., Germino, M.J., 2018, Intercomparison of surface energy fluxes, soil moisture, and evapotranspiration from eddy covariance, large-aperture scintillometer, and modeling across three ecosystems in a semiarid climate: Agricultural and Forest Meteorology, v. 248, p. 22-47,