Fluxos de massa e energia em uma floresta tropical do sudoeste da Amazônia

Mass and eneRGY FluX oveR tRoPiCal FoRest in the south west aMazon Measurements of fluxes of carbon dioxide, sensible heat and latent heat were made using the eddy covariance method in a tropical forest area in South West Amazon. The data were collected in the year of 2004 at the Biological Reserve of Jaru River, in Ji‐Parana, Brazilian state of Rondonia. Seasonal and daily patterns of variability of the fluxes and the meteorological variables were analyzed at this experimental site and compared with the behavior of the mass and energy flux data collected from 1999 to 2002 in one old site located in the same reserve only 13 km away. In the site in study the latent heat flux showed a clear seasonal change, presenting a reduction of 19,6% in the dry season, and the sensible heat flux had an inverse variation, presenting increase of 118,2% in the dry season. Although not conclusive, the integration of CO2 fluxes indicate a carbon uptake rate by the ecosystem, equivalent to 4,4 ton C ha‐1 year‐1. In general, comparing mass and energy flux between the experimental sites old and new was verified that the new one presented larger response to the dry season.

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