Physical, structural and floristic diversity of forest fragments in the upper basin of the Rio Araguaia / Caracterização física, estrutural e da diversidade floristica de fragmentos florestais na alta bacia do Rio Araguaia

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The upper Araguaia river basin region has been transformed by rapid and intensive human occupation processes that began in the 1970s, and now the landscape is highly fragmented. Remnant forests are surrounded by cotton and soybean plantations and pasture. They continue to be subjected to degradation and little is known about their ecological integrity. The objective of this research is increase knowledge of the remnant forest flora and provide support for public conservation and recovery policies for these remnant forests. This research consists of four chapters. The first chapter assessed fragmentation patterns under the assumption that intensive land occupation and agriculture compromised landscape structure and forest conservation in the basin. The second chapter assessed whether remnant forest tree size class structure differed from undegraded forests. The third chapter investigated whether forest remnants situated in close proximity to Emas National Park and incorporated into The Emas-Pantanal Biodiversity Corridor had higher species diversity than other remnants. The fourth chapter showed that species diversity was correlated with and vegetation indices obtained from satellite images, due to the indices sensitivity to changes in vegetation structure. These indices could be used in the future to highlight priority areas for conservation and in devising recovery policies. The major conclusions of this research are that the ecological integrity of remnant forests in the Upper Araguaia River Basin is compromised, predominantly due to lack of connectivity between the fragments and continuing exposure to degradation processes including tree felling and cattle grazing. Tree species diversity is high in these fragments, however, and species composition is dominated by small diameter early successional species. This research also established that vegetation indices obtained from satellite images, is a powerful tool in remnant forest species diversity modelling and can be used as a tool for environmental planning in areas under strong antropic pressure. This information is relevant to other degraded river basins in the Cerrado region. This research contributes to improved knowledge of the rich diversity of Brazilian forests and recognition that this diversity is threatened, particularly in the Upper Araguaia River basin, southwest of Goias State.

ASSUNTO(S)

estrutura diamétrica métricas da paisagem descritores de conservação fitossociology remote sensing landscape metrics diametric structure conservation descriptors sensoriamento remoto ciencias 1. diversidade florística araguaia, rio, bacia goiás (estado) 2. fragmentos florestais 3. paisagem proteção 4. fragmentação 5. comunidades vegetais 6. ecologia vegetal 7. sensoriamento remoto fitossociologia

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