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We found that benthic polychaete diversity increased towards southern latitudes. The cluster and ordination (non-metric MultiDimensional Scaling, nMDS) analyses of the distribution data, presented only two statistically significant (bootstrapping techniques) biogeographic provinces along the Chilean coast, with a break occurring between 41° and 42°S. While, our results did not support a latitudinal Rapoport effect, they did support the view that latitudinal Rapoport effects are a local phenomenon, occurring only for the Northeastern Pacific marine taxa. The relationship between latitudinal range extent and mean latitude indicated the existence of two hard boundaries at either extreme of the Chilean coast, limiting the geographical ranges of the species. However, geometric constraints tested using a Monte Carlo simulation approach showed a weak level of mid-domain effect on species richness. Finally, we propose that geometric constraint together with the geomorphology and historical characteristics of the Chilean coast explain the biogeographical patterns of benthic polychaete taxa in Chile. 相似文献
Myrtaceae, Lauraceae and Fabaceae are regarded as essential floristic elements of Atlantic forests due to their outstanding species richness, endemism levels, and ecological functions. Nonetheless, Atlantic forests are being subjected to multiple human disturbances that compromise the conservation of their flora. This study, therefore, intended to address whether there exist potential areas for conservation with great richness of tree/shrub species of the aforementioned families in different forest types within the subtropical Atlantic Forest. For this, data collected systematically across?~?23% of the subtropical Brazilian Atlantic Forest were employed. The univariate Local Moran I statistic was used to search for clusters of sample plots with great richness of species of the studied families. Six clusters were found throughout the evergreen rainforest (ERF) and Araucaria forest (AF), and most of them contained more than half of all species of these families observed on the sample plots, besides many others belonging to different families. A cluster of Myrtaceae and a cluster of Lauraceae in the ERF were the only ones that overlapped protected areas. The clusters of Lauraceae in the AF, located in ecotone zones with the ERF, had?~?50% of native forest cover, whereas the clusters of Myrtaceae and Fabaceae had?~?10% of forest cover. Inasmuch as forests in the study area have been heavily exploited, the clusters have relevant conservation value. Protected areas could be expanded or converted into more restrictive conservation categories to enhance the conservation of populations of key elements of the Atlantic Forest. Yet, non-protected areas deserve attention regarding the management of forest resources and conservation-by-use strategies.
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