Land use cover dynamic and its impacts on vegetation at Tomé-Açu municipality (northwestern of State of Pará-Brazil)

Abstract

North Eastern Pará, in the municipality of Tomé-Açu, Brazil, is quite singular in nature due to the fact that the process of colonization has been market by intense Japanese migration which occurred in the decade of the thirties. This colonization process imprinted on the landscape unique forms of land use with a dynamic until now quite unascertained. With the aim of spatially evaluating the dynamics of human alterations to this landscape and the role of the vegetation in relation to the land use, 12 km x 16 km samples were selected from two areas. To characterize the vegetation and land use with geographic processing systems TM/Landsat images from 1991 and 1995 were used, with the support of surveys in the field. It was observed that the areas of secondary vegetation, independent of their state of succession, were most predominant in the landscape even though areas of primary forest are significant. In relation to land use the areas of pasture were most prominent, and they also showed an increase during the period under consideration. In relation to the landscape dynamics, the areas of primary forest showed the highest percentages of stability, as there is a tendency to concentrate the incorporation of new areas for livestock from secondary vegetation in initial stages of regeneration. The classes for land use define the greatest fluctuations in stability, even though a significant part of these areas remain under the same use, thus minimizing pressure on the areas with forest features. The difference between the areas studies was clearer when the productive systems were analysed considering social, agricultural and technological aspects. Key words: Landscape Dynamics, Land Use/Cover Changes, Slash-and-Burn Agriculture, Amazonian Region.