The Amazon catchment is the largest river basin on earth, and up to 30% of its waters flow across floodplains. In its open waters, floating plants known as floating meadows abound. They can act as vectors of dispersal for their associated fauna and, therefore, can be important for the spatial structure of communities. Here, we focus on amphibian diversity in the Amazonian floating meadows over large spatial scales. We recorded 50 amphibian species over 57 sites, covering around 7000 km along river courses. Using multi-site generalised dissimilarity modelling of zeta diversity, we tested Hanski's core-satellite hypothesis and identified the existence of two functional groups of species operating under different ecological processes in the floating meadows. ‘Core' species are associated with floating meadows, while ‘satellite' species are associated with adjacent environments, being only occasional or accidental occupants of the floating vegetation. At large scales, amphibian diversity in floating meadows is mostly determined by stochastic (i.e. random/neutral) processes, whereas at regional scales, climate and deterministic (i.e. niche-based) processes are central drivers. Compared with the turnover of ‘core' species, the turnover of ‘satellite' species increases much faster with distances and is also controlled by a wider range of climatic features. Distance is not a limiting factor for ‘core' species, suggesting that they have a stronger dispersal ability even over large distances. This is probably related to the existence of passive long-distance dispersal of individuals along rivers via vegetation rafts. In this sense, Amazonian rivers can facilitate dispersal, and this effect should be stronger for species associated with riverine habitats such as floating meadows.

中文翻译：

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亚马逊漂浮草甸的两栖动物多样性：汉斯基核心卫星物种系统

亚马逊流域是地球上最大的河流流域，其中多达 30% 的水域流经漫滩。在其开阔的水域中，被称为漂浮草甸的漂浮植物比比皆是。它们可以作为相关动物群的传播载体，因此对社区的空间结构很重要。在这里，我们专注于大空间尺度上亚马逊漂浮草甸的两栖动物多样性。我们在 57 个地点记录了 50 种两栖动物，沿河道覆盖约 7000 公里。使用 zeta 多样性的多站点广义相异模型，我们测试了 Hanski 的核心卫星假设，并确定了在漂浮草甸中在不同生态过程下运行的两个物种功能群的存在。“核心”物种与漂浮的草甸有关，而“卫星” 物种与邻近环境有关，只是偶尔或偶然地居住在漂浮的植被中。在大尺度上，漂浮草甸中的两栖动物多样性主要由随机（即随机/中性）过程决定，而在区域尺度上，气候和确定性（即基于生态位）过程是核心驱动因素。与“核心”物种的周转相比，“卫星”物种的周转随着距离的增加而增加得更快，并且还受更广泛的气候特征控制。距离不是“核心”物种的限制因素，这表明它们即使在很远的距离上也具有更强的传播能力。这可能与个体通过植被筏沿河流被动长距离扩散的存在有关。在这个意义上，