The role of forest structure, fragment size and corridors in maintaining small mammal abundance and diversity in an Atlantic forest landscape

Author(s)

Pardini, Renata ^[1] ; Souza, Sergio Marques de ^[2] ; Braga-Neto, Ricardo ^[3] ; Metzger, Jean Paul ^[4]

Affiliation

^[1] Universidade de São Paulo (USP). Instituto de Biociências - Brasil

^[2] Universidade de São Paulo (USP). Instituto de Biociências - Brasil

^[3] Universidade de São Paulo (USP). Instituto de Biociências - Brasil

^[4] Universidade de São Paulo (USP). Instituto de Biociências - Brasil

• Document type: Journal article
• Source: Biological Conservation; v. 124, n. 2, p. 253-266, July 2005.
• Field of knowledge: Biological Sciences - Ecology

Abstract

Using the abundance and distribution of small mammals at 26 sites in an Atlantic forest landscape, we investigated how species abundance and alpha and beta diversity are affected by fragment size and the presence of corridors. To account for the variability in forest structure among fragments, we described and minimized the influence of foliage density and stratification on small mammal data. Sites were distributed among three categories of fragment size and in continuous forest. For small and medium-sized categories, we considered isolated fragments and fragments connected by corridors to larger remnants. Small mammal abundance and alpha and beta diversity were regressed against site scores from the first axis of a Principal Component Analysis on forest structure variables. Residuals were used in analyses of variance to compare fragment size and connectivity categories. Forest structure influenced total abundance and abundance of some species individually, but not the diversity of small mammal communities. Total abundance and alpha diversity were lower in small and medium-sized fragments than in large fragments and continuous forest, and in isolated compared to connected fragments. Three species were less common, but none was more abundant in smaller fragments. At least one species was more abundant in connected compared to isolated fragments. Beta diversity showed an opposite relationship to fragment size and corridors, increasing in small and isolated fragments. Results highlight the importance of secondary forest for the conservation of tropical fauna, the hyper-dynamism of small isolated fragments and the potential of corridors to buffer habitat fragmentation effects in tropical landscapes. (AU)

• FAPESP's process: 02/02126-7 - Study of the relative importance of the degree of connectivity and of the structure of the vegetation for the small mammal community in wooded fragments of the Atlantic Rainforest
• Grantee: Sérgio Marques de Souza
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 99/05123-4 - Biodiversity conservation in fragmented landscapes at the Atlantic Plateau of São Paulo (Brazil)
• Grantee: Jean Paul Walter Metzger
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 01/13309-2 - Effects of the fragmentation of the Atlantic Rainforest: a comparative study between landscapes and groups of species of small vertebrates
• Grantee: Renata Pardini
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 02/02125-0 - Effects of the fragmentation of the Atlantic Rainforest: investigating the importance of the size of the fragment and of the quality of the habitat in the structuring of the small mammal community
• Grantee: Ricardo Braga Neto
• Support Opportunities: Scholarships in Brazil - Scientific Initiation