Mapeamento de fragmentos de floresta primária na zona Bragantina-Estado do Pará

Abstract

The Amazon has been deforested indiscriminately over the last few years, which has led to landscape fragmentation. A recent survey of land use and vegetation cover in the Bragantine region of Pará state (VIEIRA 1996) showed that 15% of the landscape is forest remnant. This work aims to map these fragments in some municipalities in the region (São Francisco do Pará, covering an area of 473.58 km2 and geographic coordinates of its municipal headquarters of 01º 10'03" S and 47º 47'45" W. Gr., and Inhangapi, with an area of 471.57 km2 and coordinates of its municipal headquarters of 01º 25'45" Se 47º 54'54" W. Gr.) and provide subsidies to verify the possible influence of fragment size on species diversity. The first step was a bibliographical survey, field work to measure the geographic coordinates of the fragments with the aid of a GEO EXPLORER GPS, and the land uses that surround the forest fragments were also observed. In the making of the cartographic base the process of cartographic compilation adapted to the scale of 1:50,000 and a LANDSAT TM5 satellite image of orbit 223.061, bands 3, 4 and 5 with cloud cover 30%, from the year 1996, were used. After digitizing the image it will be possible to arrive at an analysis of the distribution of the fragments in this area with the support of the software IDRISI for windows. The preliminary results show that in São Francisco do Pará the vegetation cover consists mainly of secondary forests and the primary forests of the low plateaus are almost non-existent. Inhangapi, on the other hand, the studies have not yet been started, but it is possible to see various stages of "capoeiras", which occur on terra firme.