Fluxos de calor sensível e latente armazenados no dossel vegetativo e análise de infiltração de água no solo em floresta tropical.

Abstract

This study assessed the seasonal and annual variations in both sensible and latent heat storage fluxes in the canopy air-space of tropical rainforest, as well as the infiltration rate on rainfall exclusion plot and on actual rainfall plot. The data used in this work were obtained during the “Long-term drought impact on water and carbon dioxide fluxes in Amazonian Tropical Rainforest Experiment” (ESECAFLOR) which is subproject of Large Scale Biosphere Atmosphere Experiment in Amazon forest (LBA), carried out in terra firma rainforest in Caxiuanã National Forest, Pará, Brazil. The air temperature and relative humidity data were collected in a forest profile for each 8 m height layer throughout the 2008 year in order to determine the sensible and latent heat storage fluxes during the rainy season (February, March and April) and dry season (September, October and November). The results indicated that sensible heat stored flux in rainforest canopy during the 2008 year was 167.93 W m-2, with average and standard deviation of 0.46 and 0.96 W m-2, respectively. For the same period, the latent heat stored flux flow was 5184.38 W m-2, with average and standard deviation of 14.6 and 3.09 W m-2, respectively. The soil water infiltration rate in the rainforest is reduced drastically at the first minutes of the experiment beginning, regardless the soil moisture conditions, and then it presents a behavior almost constant throughout the time. The highest infiltration rates are recorded in the rainfall exclusion plot during the dry season.