Anuran Beta Diversity in a Mosaic Anthropogenic Landscape in Transitional Amazon
Can the loss of forest habitat cause changes in local communities? The results of our study of anuran assemblages in the southern Amazon indicate that the conversion of forest into open environments results in the substitution of species and the reduction of beta diversity. The increasing loss of tropical forests to agricultural development, especially in the Amazon, has resulted in the extensive modification of the natural landscape, transforming once-continuous forests into a mosaic of modified habitats. Our data indicate that this process resulted in the substitution of forest species by generalists, which are more typical of open environments. Also, this process has a homogenizing effect, making different areas more similar to one another, resulting in a decrease in beta diversity. This substitution–homogenization process may become increasingly common through the ongoing advance of agricultural frontiers, resulting in the local extinction of an important component of the biodiversity of tropical forests.Abstract
Location of sample plots at the Fazenda Tanguro, Querência, Mato Grosso (Brazil). In the larger map, white areas correspond to agricultural land, whereas gray areas represent the forest. Plots are distinguished by habitat type: squares = deforested area (DEF); circles = margin of the Tanguro River (TAN); diamonds = rubber plantation (RUB); triangles = preserved gallery forest (PGF); stars = disturbed gallery forest (DGF). Modified from Balch et al. (2008).
(A) Estimated species richness of aurans in each habitat type (vertical bars represent the 95% confidence interval); (B) mean β diversity (dots = mean; bars = ± SE; lines = ± SD; open circles = outliers) recorded in each habitat type. DEF = deforested area; DGF = disturbed gallery forest; PGF = preserved gallery forest; RUB = rubber plantation; TAN = margin of the Tanguro River.
Principal Coordinates Analysis (PCoA) with groups based on the Analysis of Similarity (ANOSIM) of the (A) quantitative data and (B) qualitative data on species composition. DGF = disturbed gallery forest (open circles); PGF = preserved gallery forest (black circles); RUB = rubber plantation (triangles); DEF = deforested area (crosses); TAN = margin of the Tanguro River (squares). Species over the arrows and their values represent the correlation of the species with each axis.
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