Navegando por Palavras-chave "habitat loss"

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    Biogeography, vicariance and conservation of snakes of the neglected and endangered Caatinga region, north-eastern Brazil
    (Wiley-Blackwell, 2014-05-01) Guedes, Thais B. [UNIFESP]; Sawaya, Ricardo J. [UNIFESP]; Nogueira, Cristiano de C.; Univ Estadual Paulista UNESP; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    AimOur aims were to test the predictions of the vicariance model, searching for natural, non-random biogeographical units using data on snake distributions, and to assess the conservation of biogeographical patterns and underlying processes in the poorly studied Caatinga region.LocationCaatinga region, north-eastern Brazil.MethodsWe revised and georeferenced 7352 snake occurrence records at point localities, by direct examination of voucher specimens in zoological collections and revision of literature data. We tested two predictions of the vicariance model via biotic element analysis using two datasets (all taxa and endemics) mapped onto a 1 degrees x1 degrees square grid across the Caatinga. Finally, we examined the overlap between recovered biogeographical units and spatial patterns of habitat loss and protected area coverage.ResultsWe recorded 112 snake species from the Caatinga, of which 22 (20%) are endemics. the predictions of the vicariance model were corroborated by the detection of groups of species with significantly clustered ranges (biotic elements). the analysis with the full dataset detected eight biotic elements, and three endemic biotic elements were found when only using endemics. the three endemic biotic elements correspond to core areas of biotic elements detected with the larger dataset. the average habitat loss for species forming biotic elements was 46%, and was similar among biotic elements. Protected area coverage is different for species from different biotic elements, and most species' ranges are very poorly represented in protected areas.Main conclusionsThe Caatinga harbours a peculiar snake fauna with significantly clustered species ranges concordant with the predictions of the vicariance model. Our results, representing the first formal test of vicariance patterns in the Caatinga, detected poor overlap between biotic elements and protected areas, indicating that biogeographical patterns and processes are largely unprotected in this imperilled and neglected Neotropical region.
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    Impactos potenciais das mudanças propostas no Código Florestal Brasileiro sobre os répteis brasileiros
    (Instituto Virtual da Biodiversidade | BIOTA - FAPESP, 2010-12-01) Marques, Otavio Augusto Vuolo; Nogueira, Cristiano; Martins, Marcio; Sawaya, Ricardo Jannini [UNIFESP]; Instituto Butantan Laboratório de Ecologia e Evolução; Universidade de Brasília Departamento de Zoologia; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    We evaluate the potential impacts on Brazilian reptiles (721 species already described), if the proposed changes in the Brazilian Forest Code are approved. The possibility of environmental compensation (a legal obligation in case of disturbance of natural habitats) in basins or micro basins different from that in which the disturbance occurred would have harmful effects on reptile diversity. Some reptile genera include species that rarely co-occur in space. Thus, conservation action planning based on naturally smaller scales, such as micro basins, is most suitable to maintain species composition across large regions. The proposed changes also include the removal of mountaintops as Areas of Permanent Preservation (APP, areas which must be permanently protected, despite the fact that they are not part of a park), as well as a reduction in the width of gallery forests and protected riparian habitats (which are APPs). Many Brazilian reptiles are restricted to high elevation areas, whereas others dwell only or mostly in gallery forests and riparian areas. Thus, the habitat loss that would result from these two changes could make some reptiles vulnerable to extinction. The proposed changes also include allowing the restoration of the Legal Reserves (LR, the reserves of natural vegetation which landowners have to keep in private areas) using exotic plant species. There are evidences that many Brazilian reptiles are not able to persist in human-modified environments like forests composed of exotic trees. The proposed changes also allow the compensation of disturbances imposed on LR inside existing protected areas. However, existing protected areas are not sufficient for the maintenance of reptile diversity in Brazil (mainly because many species have restricted distributions). If approved, the proposed changes in the code will impose significant negative effects on the Brazilian reptile fauna, an important component of the country's natural heritage. Furthermore, unknown molecules with potential for pharmaceutical use could also be lost.