Produção e fluxo de metano em área de floresta de terra-firme na Flona Tapajós

Abstract

Methane (CH4) is the second greenhouse gas and its concentration in the atmosphere has increased 259% since 1750. In organic form is the most abundant trace gas in the atmosphere (mixing ratio ~ 1.8 ppm). Studies to verify the regional balance of CH4 are performed with low intensity in the Amazon, so knon the contribution of tropical rainforest in the production and flow of this gas to the atmosphere in the region is important to address carbon dynamics in this ecosystem to better conceptualization of balance its biogeochemical cycle. This study aims to quantify the concentration and flow of methane in the vertical profile of the forest, as well as determine the emission of methane in the atmosphere-soil interface FLONA-Tapajós during the rainy season and the dry season for the year 2012. Air samples were collected directly in situ soil through the use of static chambers and the vertical profile through forest micrometeorlogical tower at four different heights (2 m, 16 m, 36 m and 63 m). Subsequently, the air samples were analyzed by gas chromatography. The methane concentration in the vertical profile was 1.866 ± 0.038 ppm (mean ± standard deviation), that is 1866 ± 38 ppb and the ecosystem flux was ~ 15.50 mg CH4 m-2 d-1 and methane soil emission was 0.45 ± 0.71 mg CH4 m-2 d-1. Therefore, for the period of study, the ecosystem of upland forest acted as a source of CH4 to the atmosphere.