Correspondence between physiographic classifications and spatial patterns of β diversity in mammal and bird species assemblages in the Brazilian Pantanal
Previous studies in the Brazilian Pantanal suggest that physiographic heterogeneity could be used to delimit different subregions. However, the extent to which these regionalisations reflect spatial patterns of variation in beta diversity for different taxonomic groups has not been tested yet. The a...
Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
Published: |
Asociación Argentina de Ecología
2013-04-01
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Series: | Ecología Austral |
Subjects: | |
Online Access: | http://ojs.ecologiaaustral.com.ar/index.php/Ecologia_Austral/article/view/1187 |
Summary: | Previous studies in the Brazilian Pantanal suggest that physiographic heterogeneity could be used to delimit different subregions. However, the extent to which these regionalisations reflect spatial patterns of variation in beta diversity for different taxonomic groups has not been tested yet. The aim of this paper was to evaluate whether current regionalization schemes proposed for the Brazilian Pantanal adequately describe patterns of beta diversity in mammals and birds. The presence-absence of each mammal and bird species was recorded at each of the eighty 0.5x0.5 degree cells in a squared grid map. A Jaccard similitude index was used to estimate the similarity between each pair of cells. A non-hierarchical classification method (k-means) was applied to obtain “a posteriori” classification of cells into subregions. The classification strength (CS) of each physiographic scheme and the “a posteriori” classification was the difference between mean similarity within (W) and between (B) subidivisions (CS=W-B). Both classifications (“a priori” and ”a posteriori”) showed low values of CS, which indicates that they were not suitable to represent the beta diversity patterns in mammals and birds within the Brazilian Pantanal. The results suggest that, probably because the large geographic ranges and low levels of endemism in these taxa, physiographic classifications of the Brazilian Pantanal are no reliable shortcuts to represent beta diversity patterns in mammal and birds. Thus, detailed biological inventories are necessary to propose consistent local conservation plans in this highly diverse and threatened region. |
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ISSN: | 0327-5477 1667-782X |