Brasília - Deforestation and burnings alter rainfall patterns in the Amazon forest. This is one of the conclusions reached by the Large-Scale Amazônia Biosphere-Atmosphere Experiment's (LBA) Millenium Institute project, coordinated by Paulo Artaxo, a scientist attached to the University of São Paulo's Institute of Physics. The study will be presented and discussed at the III Scientific Conference of the LBA, which begins today in Brasília.

The project involves 120 researchers who study changes in soil use and their impact on the climate. The project is funded by the Ministry of Science and Technology.

The researchers monitored the climate in ten sites scattered east and west in the Amazon region, from Pará to Acre. They have already discovered, for example, that, in the majority of the sites, each hectare of forest absorbs a half ton of carbon annually. "If this were multiplied by the approximately five million square kilometers of forest, we could assert that Amazônia is, possibly, the largest absorber of the atmosphere's carbon gas," Artaxo observed.

The scientist emphasized, however, that one cannot perform a simple multiplication exercise to calculate carbon absorption, because the forest is heterogeneous, with rainfall and solar radiation patterns that vary according to location.

In Santarém (Pará), for example, researchers from the Millenium Institute found that there is a net annual loss of carbon on the order of 3 tons per hectare. That is, there is no absorption. The explanation is that, in this region, the forest is drier and has a very high decomposition rate. There are more dead trees decaying than new ones germinating.

Agência Brasil
Reporter: Lana Cristina
Translator: David Silberstein
07/27/2004