ABSTRACT: Rocky shores are a transitional ecosystem between land and marine environments, and, together with other benthic coastal habitats, have a diverse macrobenthic community. Although there is enough information about the taxonomic diversity of Argentinean rocky shores, studies with a functional approach are scarce. We applied biological traits analysis and functional diversity indices to evaluate the geographic variation of the functional diversity of macrobenthic assemblages on rocky shores along a latitudinal gradient in the SW Atlantic (from 37° to 50°S). A total of 11 beaches with rocky hard substrate belonging to 2 biogeographical provinces (Magellanic and Argentinean) were studied during April 2016. The trait composition of macrobenthic assemblages and functional diversity indices (Rao’s quadratic entropy) varied significantly along the Argentinean coast, suggesting that the latitudinal gradient influences the distribution of species with respect to combinations of trait modalities. Rao’s quadratic entropy, species richness, evenness, and Shannon-Wiener diversity showed a pattern with higher values in the sites located in high latitudes. The functional diversity patterns found coincide with the biogeographical provinces. The presence of intertidal sewage effluents considerably influence functional diversity and mask the effects of the latitudinal gradient on the macrobenthic communities on rocky shores.

中文翻译：

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西南大西洋多岩石海岸的功能多样性：污水流出影响并掩盖了纬度梯度的影响

摘要：多岩石的海岸是陆地和海洋环境之间的过渡生态系统，并且与其他底栖沿海栖息地一起，拥有多样化的大型底栖动物群落。尽管有足够的关于阿根廷多岩石海岸分类学多样性的信息，但缺乏实用的研究方法。我们应用生物特征分析和功能多样性指数来评估西南沿海大西洋沿纬度梯度（从37°到50°S）的岩质海岸大型底栖动物组合的功能多样性的地理变化。2016年4月，共研究了11个具有岩石硬质基底的海滩，这些海滩属于2个生物地理省（麦哲伦和阿根廷）。大型底栖动物的性状组成和功能多样性指数（Rao二次熵）在阿根廷海岸上变化很大，这表明纬度梯度会影响到性状模态组合的物种分布。Rao的二次熵，物种丰富度，均匀度和Shannon-Wiener多样性在高纬度地区显示出较高值的模式。发现的功能多样性模式与生物地理省一致。潮间带污水的存在极大地影响了功能多样性，并掩盖了纬度梯度对多岩石海岸大型底栖动物群落的影响。这暗示了纬度梯度会影响到性状模态组合的物种分布。Rao的二次熵，物种丰富度，均匀度和Shannon-Wiener多样性在高纬度地区显示出较高值的模式。发现的功能多样性模式与生物地理省一致。潮间带污水的存在极大地影响了功能多样性，并掩盖了纬度梯度对多岩石海岸大型底栖动物群落的影响。这表明，纬度梯度会影响到性状模态组合的物种分布。Rao的二次熵，物种丰富度，均匀度和Shannon-Wiener多样性在高纬度地区显示出较高值的模式。发现的功能多样性模式与生物地理省一致。潮间带污水的存在极大地影响了功能多样性，并掩盖了纬度梯度对多岩石海岸大型底栖动物群落的影响。