Annual Distribution of Energy Fluxes in a Tallgrass Prairie Related to Canopy Growth

Measurements of surface energy and water fluxes, supporting weather parameters, green leaf area, biomass, and soil moisture were made at a tallgrass prairie site in north-central Oklahoma. In this paper, annual patterns of surface energy budget components will be presented and examined in terms of canopy growth periods. The canopy growth periods will be determined in two ways: conventionally (using green leaf area index) and with modified approach (using the photosynthetically active radiation albedo in conjunction with leaf area index). Annual behavior of the energy budget components is explained better when using the modified approach. The latter provided more detailed assessment of the growth periods, and helped determine borders between growth periods with better confidence, as compared to the conventional approach. Details on the energy budget components within each growth period will also be discussed.