Balanço de energia em áreas de floresta e de um campo agrícola no leste da Amazônia

Abstract

This study is based on observations and data measured by the network micrometeorological towers installed in the experimental sites LBA in the region of Santarém. The fluxes towers are located two within the Tapajos National Forest (TNF), an area in for management forest (km 83) and one in Primary forest area (km 67), the third flux tower is installed in an agricultural area in of 77 km along the BR 163. The objective this work was to evaluate the surface energy balance in the experimental site LBA in Santarém-PA on different regions (Agricultural Field, management and Primary Forest). To this was estimated latent heat flux (LE) and sensible heat flux (H), net radiation (Q *), the of ground heat flux (G), energy storage rate in the air and biomass (S). Through these results it was found that, different from the agricultural field, the variation of albedo in the management forest was associated with the effects seasonality with higher values in the dry season, and lower values in the wettest. About to the Q *, for areas of forest (managed and primary) we found that Q * was 2,5% higher than in agricultural field. Regarding the components of the energy balance, the flux of heat in the ground (G) was a term considerable Surface Energy Balance closure in Agricultural Field area. Already in forest areas, S was a considerable surface energy balance closure term. The LE flux was dominant throughout the period analyzed in forest areas, except in the Agricultural Field, where found a reversal in the LE and H fluxes, especially in the period in which the soil was plowed and abandoned for regeneration, culminate in less rainy season. The Surface Energy Balance closure was better when S is included in the calculations especially in areas forest.