A importância de pequenos elementos da paisagem para a conservação da Mata Atlântica

Abstract

The Atlantic Forest in Minas Gerais, which once occupied about 50% of the state's territory, is extremely fragmented due to the old anthropic establishment in the region. Regarding public environmental policies, the most used form of conservation of the remnants of the Atlantic Forest is the protection and isolation of areas with high biodiversity (such as Conservation Units - Law 9.985 / 2000, SNUC) and / or isolation the area so the forest could regenerate naturally or through restoration practices (such as the Permanent Preservation Areas and Legal Reserves - Law No. 12,651 / 2012, New Forest Code). But the largest area that was fully occupied by forests is now inserted in agricultural and productive areas, so it is important to emphasize environmental conservation without the loss of productive areas. In the agricultural production matrix, there are small fragments of forests. Few of these fragments have an area greater than 10 hectares, and most are smaller than one hectare. And these fragments may be linked to a watercourse, that could be or not a Riparian Forest. Besides these remnants, they are others small elements of the landscape, such as: isolated trees, tree lines on trenches (long lines of trees (4 meters)) and tree lines on fences (narrow tree lines (< 2 meters)). In this context, understanding the importance and the dynamics of small landscape elements -SLEs is critical to the establishment of strategies for both the conservation and management of biological diversity in productive areas. The present study addressed these issues in an unprecedented manner, evaluating the variation of small elements (fences, trenches, isolated trees, small fragments (< 1 ha) and riparian forest) across the landscape, as well as accessing their effectiveness in gene flow, and functional connectivity. As a result, we found the following land - use classes in landscapes: 62.6% of pasture, 0.5% of water, 3.0% of agriculture, and 0.3% of eucalyptus plantations. The fragments larger than 1 hectare correspond to 25.9%, and small landscape elements to 7.4% of the studied area. Despite the small area occupied by these small elements, we see that they provide functional connectivity for animals; and that they increase the effectiveness of gene flow for a generalist plant, as they decrease the resistance of the landscape. These results should be used to support management and conservation strategies for these elements within the context of activities inherent to rural properties, allowing the maximization of conservation gains in the context of the economic use of land, optimizing the sustainable use of rural properties.