Composition and abundance of small mammal communities in forest fragments and vegetation corridors in Southern Minas Gerais, Brazil

Andréa O Mesquita,Marcela Passamani

doi:10.15517/rbt.v60i3.1811

Abstract

Habitat fragmentation leads to isolation and reduce habitat areas, in addition to a series of negative effects on natural populations, affecting richness, abundance and distribution of animal species. In such a context, habitat corridors serve as an alternative for connectivity in fragmented landscapes, minimizing the effects of structural isolation of different habitat areas. This study evaluated the richness, composition and abundance of small mammal communities in forest fragments and in the relevant vegetation corridors that connect these fragments, located in Southern Minas Gerais, Southeastern Brazil. Ten sites were sampled (five forest fragments and five vegetation corridors) using the capture-mark-recapture method, from April 2007-March 2008. A total sampling effort of 6 300 trapnights resulted in 656 captures of 249 individuals. Across the 10 sites sampled, 11 small mammal species were recorded. Multidimensional scaling (MDS) ordinations and ANOSIM based on the composition of small mammal communities within the corridor and fragment revealed a qualitative difference between the two environments. Regarding abundance, there was no significant difference between corridors and fragments. In comparing mean values of abundance per species in each environment, only Cerradomys subflavus showed a significant difference, being more abundant in the corridor environment. Results suggest that the presence of several small mammal species in the corridor environment, in relatively high abundances, could indicate corridors use as habitat, though they might also facilitate and/or allow the movement of individuals using different habitat patches (fragments).

Highlights

Brazil is among the richest countries in the world in animal species diversity, and it is the richest in mammal species (Costa et al 2005)
In Southern Minas Gerais, Brazil, the landscape consists of many small forest fragments imersed in an anthropogenic matrix and some of these fragments are connected through vegetation corridors
According to Castro (2004) the origin of the vegetation corridors in Southern Minas Gerais can be connected to two different factors: One of them would be the linear strips of remnant vegetation left after clearcut in the forests to create boundaries between rural properties

Summary

Introduction

Brazil is among the richest countries in the world in animal species diversity, and it is the richest in mammal species (Costa et al 2005). Fragmentation leads to isolation too and triggers a number of negative effects on wildlife populations, affecting the richness, abundance, and distribution of species (Brooks et al 2002, Fahrig 2002, Fischer & Lindenmayer 2007, Pardini et al 2009, Vieira et al 2009). On a broader time scale, fragmentation affects genetic variability and persistence of populations, potentially leading to local extinctions (Fahrig & Merriam 1994, Gibbs 2001, Viveiros de Castro & Fernandez 2004). The aim of this study was to evaluate the richness, composition, and abundance of small-mammal communities in forest fragments and in connecting vegetation corridors

Objectives

Methods

Results

Conclusion