Análise da estrutura da paisagem da alta bacia do rio Araguaia na savana brasileira

Abstract

Landscape structure analysis of the upper Araguaia river basin in the brazilian savanna. The Central- West region of Brazil was extensively covered by Savanna physiognomies at the end of 1970`s, when large transformations, due to expansion of agriculture frontier and agriculture modernization, promoted an intensive and fast deforestation. The vegetation that remains today is in the fragments form, which can suffer several effects that can lead to the decrease or disappearance of species. The changes that occurred in a landscape can be studied through the methods of Landscape Ecology, by evaluating the indices or metrics for quantitative characterization, allowing to compare landscapes, identify differences and determine relationships between the functional processes and the patterns of those landscapes. The objective of this paper was to analyze the structure of the landscape in the upper Araguaia river basin, in five years (1977, 1989, 1997, 2002 and 2006), to evaluate its pattern of fragmentation along the time, after the intensive deforestation. The results showed that the methodology used was satisfactory. The fragmentation revealed notable rate of conversion of the original physiognomies in pasture and agricultural lands and the metrics of the area, core area, shape and isolation of the natural classes showed that the fragments, in relation to its integrity, are under strong threat.