Trait variation across environmental gradients results from two processes: intraspecific variation (ITV) and turnover. Trait plasticity promotes intraspecific variation and can mediate, increasing or decreasing, interspecific variation. Here we evaluate patterns of ITV and trait-environment relationships in an anuran metacommunity from southern Brazil. We hypothesize that the contribution of ITV and turnover to trait variation and trait-environment relationships should vary between groups of habitats use and traits. To test this, we sampled anurans in 33 ponds and selected the eight most abundant species, which were grouped as arboreal or aquatic-terrestrial according to their use of space. We evaluated the following traits: head shape, eye size and position, limb length and body mass. We divided variation in community trait composition into ITV, variability due to turnover, and also the covariation between them. We modelled trait-environment relationships using linear mixed-effect models. ITV and turnover contributed similarly across traits, but differentially between sets of species. Trait variation seems to be mostly driven by ITV in arboreal anurans and by turnover in aquatic-terrestrial species. Depth, distance between ponds, area of Pinus surrounding the ponds, and types of pond vegetation and substrate strongly influenced trait variation, but their relative contribution depended on the analysed traits and species sets. The dominant contribution of ITV towards the variation of head shape and eye size and position suggests the existence of intraspecific adaptations to microhabitats, while turnover dominance in the variation of body mass and limb length suggests differences in dispersal and trophic segregation between species.

中文翻译：

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周转或种内性状变异：解释新热带无尾动物群落的功能变异

跨环境梯度的性状变异来自两个过程：种内变异 (ITV) 和周转。性状可塑性促进种内变异，并可以调节、增加或减少种间变异。在这里，我们评估了来自巴西南部的 anuran 元群落中 ITV 和特征-环境关系的模式。我们假设 ITV 和周转对性状变异和性状-环境关系的贡献应该因栖息地使用和性状的群体而异。为了测试这一点，我们在 33 个池塘中采样了无尾类，并选择了 8 个最丰富的物种，根据它们对空间的使用将它们分为树栖或水陆生物。我们评估了以下特征：头部形状、眼睛大小和位置、四肢长度和体重。我们将社区特征组成的变化划分为 ITV，由于营业额而产生的可变性，以及它们之间的协变。我们使用线性混合效应模型对特征-环境关系进行建模。ITV 和营业额对性状的贡献相似，但在物种组之间存在差异。性状变异似乎主要由树栖无尾目中的 ITV 和水陆生物物种的更替驱动。深度、池塘之间的距离、池塘周围的松树面积以及池塘植被和基质的类型强烈影响性状变异，但它们的相对贡献取决于分析的性状和物种集。ITV 对头部形状、眼睛大小和位置变化的主要贡献表明存在对微栖息地的种内适应，