Spatial structure on a slope in a Tropical Semideciduous Forest in Ipero city, São Paulo State, Brazil

Author(s)

Felipe Segala Ferreira

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2010-12-02

Examining board members

Fernando Roberto Martins; Rafael Silva Oliveira; Osmar Cavassan

• Advisor: Fernando Roberto Martins

Abstract

Processes of species distribution in tropical ecosystems encompass complex and multiple interactions with the environment. Environmental heterogeneity permits the coexistence of species because it creates different niche opportunities. Through the patterns revealed in the community structure it is possible to distinguish between the most likely types of community assembly, the deterministic or stochastic. We investigated whether the community structure is related to environmental determinism in microscale. We described the community structure through species richness, Simpson's index of concentration, density and basal area; and the environmental heterogeneity through microtopography variation, soil depth and rockiness. We performed spatial and non-spatial correlations and use t-test modified by Cliff & Ord to test for average differences in autocorrelated data sets. Species richness exhibited a spatial structure that correlated negatively with microtopography. Density did not exhibit spatial structure, but was positively correlated with microtopography. There was no difference between species richness of concave and convex subcommunities. Average density was greater in concave than in convex subcommunity. Soil depth and rockiness did not influence community structure. Our results suggest that the microtopography variation associated with the climate seasonality can have determined the structure of the community. (AU)