Influência da estrutura de paisagens em parâmetros da biodiversidade com foco em pequenos fragmentos e corredores de vegetação no bioma da Mata Atlântica, Minas Gerais, Brasil

Abstract

Structural factors as like vegetation remnants, isolation and connectivity between forest patches are intrinsic related to biodiversity. Small patches and connectors are considered important in maintaining species in landscapes with high level of fragmentation and habitat loss. Despite the size, these element increase the landscape connectivity, and the available area to species. Atlantic Forest remnants are distributed in small fragments (less than 50 hectares), often inserted into an anthropogenic matrix. Even threatened , this biome presents a high species richness and endemism. Despite they importance, studies usually have focused on the analysis and quantification of preserved fragments, and there is a lack of information about the abundance and spatial arrangement of small features. The aim of this study was to quantify and analyze the spatial distribution of small features in 49 sample sites in Atlantic Forest fragmented landscapes at Minas Gerais State, Brazil. We tested the relationship between the remnant vegetation, isolation and hedgerows length with distance to landscape features, slope, altitude, number and fragments area. We also tested the connectivity for several capacity to cross the matrix, the relation of fragments with the surrounding matrix and the importance of small fragments to landscape isolation. We mapped the landscape features using a multispectral classification of high spatial resolution images (5m) applying a object-based semi automatic method. Results showed a variable percentage of remaining vegetation in the sample sites (4.1% to 69.7%), most of them with fragments smaller than 1 h (from 45 to 97%). The largest number of hedgerows was found in the southeastern state. Statistical analyzes based on the AICc model selection indicated the influence of physical, structural and political divisions in the amount of vegetation , isolation and size of corridors landscapes factors. Small fragments (< 100 ha) and hedgerows (width ≤ 15 m) are important elements in the connection between the fragments.