Fire in the Xingu Region: its Determinants and Effects on Vegetation and Socio-Environmental Relevant Resources

Resumo

Slash-and-burning agricultural systems represent an important source of food for indigenous communities in Amazonia and have been conducted for centuries or millennia. However, the traditional use of fire has ignited an increasing number of wildfires. In 2010, for instance, 298,000 hectares of forests burned in the Xingu Indigenous Park (XIP). Yet, it is still unclear what are the main factors driving this apparent change in fire regimes inside the PIX, as well as the consequences of such changes to vegetation dynamics, ecosystem services, and food security for the indigenous communities. Here we describe the activities we are conducting on the scope of a project that aims to quantify the causes and consequences of changes in fire regimes inside the XIP and are funded by the Brazilian National Research Council (CNPq) and the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA). Objectives of the project include: 1) mapping burned areas inside the PIX over the past few decades using high-resolution imagery, differentiating those fire scars in slash-and-burn areas from wildfires in primary forests; 2) quantification of the combined roles of forest fires, droughts events, and forest management by indigenous peoples on recent changes of forest cover inside the XIP. Preliminary results indicate large areas on forest the XIP are now degraded mainly as a result of the increases in the burned area in the past two decades. The number of fire events in combination with number of drought years were the main predictors forest degradation. Overall, results of this project will contribute to a better understanding of the drivers of regional changes in fire regimes. We are also generating valuable information about management techniques that can reduce fire-related degradation of native forests and the ecosystem services that these forests provide for indigenous peoples, what can be used to improve food security for local communities of the PIX.