Estimativas da dinâmica de carbono na biomassa lenhosa de terra firme na reserva de desenvolvimento sustentável amanã por métodos dendrocronológicos

Abstract

Forests upland are known to be dense, with high diversity of species. As a result, contribute to store a large amount of carbon in biomass. This study estimated C-storage and C-sequestration in woody biomass in the Sustainable Development Reserve Amanã where such information is still lacking. In three plots of 1 hectare each, were inventoried all trees above 10 cm DBH (diameter at breast height). Of all the trees were measured DBH. Height was measured in 919 individuals for the other trees the height was estimated by a regression model nonlinear correlation between DBH and height. Of all the species were estimated wood densities relating dry weight to fresh volume. Of all the species were estimated ages and diameter increment rates using growth rings that form the trees each year due to seasonality of precipitation distinct. DBH, height and density of all trees were used to estimate woody biomass and its C-storage (50%) through three models were fitted. A multiple regression model was calibrated to estimate the age of the tree through the DBH and the density of wood. Thus it was possible to describe the age structure of the forest and to estimate the changes in carbon stock in the years which allows estimates of carbon sequestration in woody biomass. From the dendrochronological analysis determined the wood density of some species (0.18 to 0.92 g cm-3) and age of the forest (295 years). These data added to the floristic survey allowed us to apply allometric models that estimated biomass of 188 to 213 Mg ha-1. The C-storage was estimated between 94 to 106 Mg ha-1. The C-sequestration ranged from 2.4 to 3.1 mg ha-1 yr-1 and the C-turnover in place is estimated between 34 to 43 years. Comparing these results with other estimates for land near Manaus, floodplain and Sustainable Development Reserve Mamirauá and igapó Sustainable Development Reserve Amanã, there was a resemblance to the floodplain. This led us to conclude that the upland site that has similar yield to the floodplain is very likely that the study site is a terrace or ancient Holocene floodplain.