a1 Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14 no. 321, 05508–090 São Paulo, SP, Brazil
Edge effects encompass biotic and abiotic changes resulting from the interaction between two different habitat types (Murcia 1995). Edge habitats are ecologically distinct from patch interiors, and understanding how ecological patterns change near edges is important in understanding landscape-level dynamics such as the impacts of fragmentation (Ries et al. 2004). Abiotic conditions at the forest edge, such as increased wind and solar radiation, increased fluctuations in temperature, and decreased humidity, may affect forest-adapted organisms (Harper et al. 2005, Murcia 1995). So, edges may affect lizards and amphibians due to their physiological needs (Lehtinen et al. 2003, Vallan 2000). Anurans are considered sensitive to environmental changes due to their permeable skin, shell-less eggs and use of land as well as freshwater habitats (Vallan 2000). Changes in vegetation structure and microclimate are likely to be the predominant factor affecting amphibian abundances across edges (Jellinek et al. 2004, Marsh & Pearman 1997, Schaepfer & Gavin 2001, Urbina-Cardona et al. 2006).
(Accepted July 04 2008)