Forest Fragmentation And Landscape Structure In The Guamá River Basin, Eastern Amazon

Abstract

The Guamá River basin, in the northeastern state of Pará, eastern Amazon, Brazil, encompasses approximately 1,200,000 hectares. It presents great economic and social importance and is under significantly changes in land use and land cover. The objective of this work was to analyze and characterize the landscape structure of this basin through landscape ecology indexes (density, size, metric variability, shape, core area, proximity indexes, and patch area index). Land use and land cover maps were developed using images from the RapidEye system through supervised digital classification. The vegetation and landscape structure were quantified in patches, classes, and land cover. The forest patches were associated with partial conservation of some areas where production sectors had not yet directly affected, or those from natural regeneration of abandoned areas, mainly pastures. The class vegetated area was the second class most representative of the Guamá River basin covered about 37% considering the total area. The basin landscape presented more than 34,000 vegetated area patches It showing that this class are very fragmented by the presence of a large number of small patches, with this the basin landscape is compromised regarding its ecological integrity, since more than half of its forest patches are in edge environments. The indexes enabled a good joint analysis of the sub-basins of the Guamá River basin, resulting in a more detailed overview of the forest fragmentation process.