Evapotranspiration and energy exchange in a temperate forest in Mexico

Abstract

In forest ecosystems the energy balance, the water cycle and the carbon cycle are linked through the evapotranspiration process. Evapotranspiration is highly variable in space and time since it is controlled by numerous biophysical factors. The objective of this study was to analyze the seasonal variability of evapotranspiration and identify the main factors that influence this process. The eddy covariance technique was used to measure fluxes of sensible heat and latent heat (equivalent to evapotranspiration) in a temperate forest under forest management, located in the region of Zacualtipán, Hidalgo, Mexico. Simultaneously, net radiation, soil heat flux, soil moisture content and other meteorological parameters were measured. During the analyzed period, the proportion of the net radiation with the latent heat and sensible heat fluxes was similar most of the time. The total annual evapotranspiration observed was 980 mm. It was lower in the “cold front” season and no differences were found between the rainy season and the dry season. Temperature, soil moisture, net radiation and vapor pressure deficit explained most of the variability of evapotranspiration. Further studies are necessary to involve the analysis of ecosystem productivity and water use efficiency, to better understand ecosystem processes and identify appropriate sustainable forest management practices.