Dynamics of vegetation structure in a fragmented landscape in Minas Gerais, Brazil

N V Salomão,E L M Machado,M D D Silva

doi:10.1590/1519-6984.188643

Abstract

Considering that area and edge effects are the most important factors that lead to landscape changes from the fragmentation of terrestrial communities, the present study aimed to analyze changes in the structure of vegetation classes of a fragmented landscape. The methodology employed was based on a model of patch dynamics for the years between 1979 and 2015. The analysis was performed with quantitative (area, shape and edge effect) and qualitative (low declivity of the terrain, fire resistance and tolerance to variation in light) variables of the classes of vegetation. Processes of retraction and expansion of the vegetation classes were identified, as well as the alteration of the structure of the fragments, which resulted in the intensification of the edge effect.

Highlights

Brazil is rich in forest ecosystems, and the state of Minas Gerais (MG) possesses a concentration of varied formations due to its geological, topographic and climatic physical condition (Lopes et al, 2002), the natural cover of much of the country has been reduced to remnants of different sizes
The current accelerated pace of change has been the greatest challenge for the conservation of Brazilian ecosystems due to the processes of landscape fragmentation, which are responsible for changes in the diversity and composition of the communities involved (Metzger et al, 1998)
Changes caused by edge effects are due to the pressure exerted by the external environment on the fragments, with their intensity varying according to the nature of the activities in the area around the fragment (Abdo et al, 2015)

Summary

Introduction

Brazil is rich in forest ecosystems, and the state of Minas Gerais (MG) possesses a concentration of varied formations due to its geological, topographic and climatic physical condition (Lopes et al, 2002), the natural cover of much of the country has been reduced to remnants of different sizes. The current accelerated pace of change has been the greatest challenge for the conservation of Brazilian ecosystems due to the processes of landscape fragmentation, which are responsible for changes in the diversity and composition of the communities involved (Metzger et al, 1998). Area and edge effects are the most important factors that lead to changes in fragmented communities (Nascimento and Laurance, 2006). While area effects are ecological changes that are proportional to the fragmented area (Shaffer, 1981), edge effects are caused by physical and biotic changes near forest edges and are proportional to the distance to the nearest edge (Murcia, 1995). Changes caused by edge effects are due to the pressure exerted by the external environment on the fragments, with their intensity varying according to the nature of the activities in the area around the fragment (Abdo et al, 2015).

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Results

Conclusion