INTRODUCTION the Open pasture presents an ample geographic distribution, mainly for Brazilian Central Plateaus, enclosing the States of Gois, Tocantins and Federal District, part of Minas Gerais, Bahia, Piau, Mato Grosso, Mato Grosso of the South, Cear, Maranho, Rondnia and So Paulo, understanding about two million Km2, approximately 23% of all Brazilian, being as bigger territory bioma of Brazil (Ribeiro & Walter, 1998). The Open pasture also occurs in areas disjoins to the north in the states of the Amap, Amazon, Par and Roraima, and to the south, in small islands in the Paran. It has other peripheral open pasture areas, ectonos calls or, that are transistions with biomas Amaznia, Atlantic Bush, Caatinga and in the Pantanal. For Arruda (2004), the landscape of this Bioma is characterized by extensive campestres formations and forests mesfilas or sub-forests. In the vegetations of these landscapes variations in the composition occur florsticas, fitossociologica and productivity of these natural ecosystems had some factors as litologia, geomorfologia, relief and altitude, hydrography, ground and climate. The varied types, fitofisionmicos fit in forest formations (it kills ciliar, it kills dries, bush of gallery, cerrado), savanicas (open pasture strictu open pasture sense, park, palmeiral and trail) and campestre (dirty field, field repustre and clean field) Malheiros (2004), are characterized by a space heterogeneidade of these regions that, are represented by the diversity of climates, ground, topography, latitude, frequency of forest fires, depth of the ground fretico, pastejo and antrpica action that reflects in a mosaic different types of vegetation found in this bioma (Garlic & Martins, 1995; Ribeiro and Walter, 1998). According to Ribeiro & Walter, (1998), the open pasture stricto sensu, assigns one of the fitofisionmicos types that good defined for the florstica composition and the fisionomia occurs in the formation of the Open pasture. He has an ample one distribution for central plateaus, occupying 70% of the total area of the Open pasture.