RESUMO
Causal mechanisms for broad-scale reef fish diversity patterns are poorly understood and current knowledge is limited to trends of species richness. This work compared the effects of ecological drivers on components of fish diversity across reefs spanning over 2.000 km of the tropical Brazilian coastline. A quarter of communities' diversity is accountable to common and dominant species, while remaining species are rare. Low-latitude sites were more diverse in rare species. Communities along the coast share common and dominant species, which display high densities across all reefs, but differ in rare species that show abundance peaks in particular reef morphotypes. The disproportionate distribution of rare species reveals a higher vulnerability of these communities to impacts and stochastic density fluctuations. Uneven conservation efforts directed to these morphotypes pose a threat to the maintenance of a paramount component of the reef fish diversity represented by rare species.
Assuntos
Biodiversidade , Recifes de Corais , Peixes , Animais , BrasilRESUMO
Protected areas are an important strategy to safeguard biodiversity. However, if social development is not considered, biological conservation targets may not be achieved. In this empirical study, we assess the relationship between poverty and conservation goals in dry forests within a 62,000-ha Brazilian National Park (Caatinga biome). We conducted 81 structured household interviews between January and July of 2016 to assess socioeconomic, resource management and land-use variables. We used non-parametric analysis of variance to test for differences in socioecological variables among families living inside and outside the Park and both (double dwelling). The majority of families (76%) residing inside the Park were living below the poverty line while less than 14% in outside and double dwelling residences faced the same issue. Families living inside the park had lower socioeconomic conditions such as limited water availability, poor house infrastructure, low income, and high dependence on firewood than outside and double dwelling families. They were also more dependent on external financial support and natural resources. We found that failures in protected areas inception and implementation have driven people towards a mutually reinforcing and declining situation in which negative socioeconomic outcomes are associated with nature degradation. Therefore, our results suggest that the future of dry forests, characterized worldwide by the presence of low-income populations, will be largely dependent on conservation strategies that address poverty alleviation and human well-being.