Forest regeneration and landscape dynamics: interaction between habitat heterogeneity and quantity for species distribution in fragmented landscapes

• Grant number: 12/02971-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2012
• End date: June 30, 2013
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Renata Pardini
• Grantee: Paula Koeler Lira
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Biodiversity in fragmented landscapes is defined not only by the size and isolation of fragments, but also by the total amount of remnant native vegetation in the landscape. There is evidence that this property is associated with landscape connectivity and that an abrupt loss of species occurs below a threshold in the amount of native vegetation. However, tropical landscapes are very dynamic and, thus, deforestation and regeneration processes results in a mosaic of forests of varying age of regeneration. This habitat heterogeneity should have a strong influence on species distribution but have been ignored in empirical studies. Here, we intend to investigate how the heterogeneity of native vegetation interacts with the total forest cover in determining species distribution. To this aim we will use a large dataset on the distribution of 30 small mammal species in 50 forest fragments from three Atlantic Forest landscapes with different total forest cover (10, 30 and 50%) and native vegetation in different successional stages. We hypothesized that species response to habitat heterogeneity should be defined by habitat requirements and depend on total forest cover (landscape connectivity). The distribution of habitat generalists should depend on the local amount of native vegetation in earlier stages of regeneration regardless of total landscape forest cover. The distribution of forest specialists should depend on the local amount of native vegetation in later stages of regeneration, but only in landscapes with low and high levels of total forest cover, where species persistence in fragments is more dependent on survival and recruitment rates than on immigration rates.