Coastal habitat mosaics are among the most productive ecosystems around the globe, with many ecological and social-economic services provided. Their natural challenging conditions have always been a subject of concern for ecologist and conservationist, with a particular interest in understanding how its spatial and temporal dynamics influence ecosystem functioning. In this context, we aimed to assess tropical coastal dynamics using an integrative approach, measuring the different facets of fish diversity across space (habitats) and time (seasons). Three different estuarine systems and their adjacent areas in the southwestern Atlantic were monthly sampled between July 2017 and June 2018, in a sampling design that encompassed three different coastal mosaics with three habitat types (mangroves, seagrass and sandy beaches), and both seasons of the studied region (dry and rainy). Taxonomic, phylogenetic, and functional diversity were then evaluated with equivalent diversity measures to allow comparisons between them. Different patterns of species occurrence and distribution were found between habitats and seasons, which resulted in different effects on the abundance-weighted diversity dimensions. Although taxonomic diversity of habitats was greater during the rainy season (p = 0.03), a seasonal increase in phylogenetic diversity was only observed in the sandy beach habitat (p = 0.04). In contrast for the functional diversity, no significant differences were found among habitats in both seasons (p = 0.15), indicating high levels of redundancy. Our results showed that patterns in the occurrence and abundance of tropical fish species among habitats that comprise a coastal mosaic have different effects on distinct diversity dimensions. More precisely, for tropical coastal systems with marked seasonality, both habitats and season appear to play a synergic role in the maintenance of ecosystem functioning by enhancing functional and phylogenetic redundancy.

沿海栖息地马赛克是全球生产力最高的生态系统之一，提供了许多生态和社会经济服务。它们的自然挑战性条件一直是生态学家和保护主义者关注的主题，他们特别有兴趣了解其空间和时间动态如何影响生态系统功能。在这种情况下，我们旨在使用综合方法评估热带沿海动态，测量跨空间（栖息地）和时间（季节）鱼类多样性的不同方面。在 2017 年 7 月至 2018 年 6 月期间，每月对大西洋西南部的三个不同河口系统及其邻近区域进行采样，采样设计包括具有三种栖息地类型（红树林、海草和沙滩）的三种不同的沿海马赛克，以及研究区域的两个季节（干燥和雨天）。然后用等效的多样性措施评估分类学、系统发育和功能多样性，以允许它们之间的比较。在生境和季节之间发现了不同的物种发生和分布模式，这导致对丰度加权多样性维度的影响不同。尽管在雨季栖息地的分类多样性更大（p = 0.03），但仅在沙滩栖息地中观察到系统发育多样性的季节性增加（p = 0.04）。与功能多样性相比，两个季节的栖息地之间没有发现显着差异（p = 0.15），表明冗余度很高。我们的结果表明，构成沿海马赛克的栖息地中热带鱼类物种的出现和丰度模式对不同的多样性维度具有不同的影响。更准确地说，对于具有明显季节性的热带沿海系统，栖息地和季节似乎通过增强功能和系统发育冗余在维持生态系统功能方面发挥协同作用。