ID do Resumo: 546

Continued Declines in Mature and Secondary Forest Cover in a Previously Settled Region of Eastern Pará

While most interest in rates of Amazonian deforestation focuses on frontier areas, the amount of forest cover in areas already dominated by human settlement is also changing. Secondary forests play an increasingly important role for maintaining genetic diversity, hydrological functioning, and greenhouse gas emissions of altered landscapes, but secondary forests are also being converted to more intensive agricultural uses. We analyzed five dates of Landsat imagery from 1984 to 2002, covering 8,000 km2 of the Zona Bragantina of eastern Para state, which underwent its most intensive wave of deforestation several decades ago. However, even in this area of relatively long-term human occupation, we found ongoing losses of both the small remaining areas of mature forest and in the more widespread areas of secondary forests as human population increases and as the uses of the land intensify. Although there was an initial increase in the area of secondary forest from 1984 to 1994, there has been a steady decline since then, from 70% secondary forest cover in 1994 to 40% of the region in 2002. The amount of pasture was relatively stable from 1984 to 1994 but more recently has shown a steady increase, particularly in clean pasture or “pasto limpo”, which has tripled since 1999. The area of under cultivation has also increased since 1994. Increasing areas of pasture and agriculture combined with losses of both mature and secondary forest cover imply continued losses of C to the atmosphere, which may not be included in regional estimates of carbon flux based on analysis of deforestation in frontier areas.

Sessão:  Mudanças de Uso e Cobertura das Terras e suas Dimensões Sociais - O papel das florestas secundárias na Amazônia.

Tipo de Apresentação:  Oral