Seasonal and interannual variability in surface energy partitioning and vegetation cover with grazing at shortgrass steppe

We evaluated shortgrass steppe energy budgets based on the Bowen Ratio Energy Balance method for three different grazing intensity treatments at the Central Plains Experimental Range Long-Term Ecological Research (CPER-LTER) site. We tested the correlations between aboveground biomass and surface energy fluxes for three different precipitation years based on continuously measured 20 min interval data.Grazing has a potential impact on energy partitioning under conditions of higher water availability, but not during dry conditions. Our study confirms that precipitation, not grazing treatment, explains the majority of variation in aboveground biomass at the CPER-LTER site. In addition, we are suggesting effective temperature, not air temperature, as a superior metric to evaluate surface heat change. Effective temperature takes into account humidity as well as air temperature.

Research highlights► Green biomass increased with increasing latent heat flux and decreasing sensible heat flux during the wet periods but not during the dry periods. ► We found clear seasonal and interannual variability that followed expectations for most response variables. ► Variability of forage production explained primarily by precipitation and soil moisture rather than grazing intensity. ► We did not find major differences among grazing treatments in aboveground biomass or energy fluxes.