By providing food, living space and reducing biotic and abiotic stress, habitat‐formers support diverse communities. The characteristics that mediate their value to associated organisms, however, are not always clear. Traditional assessments of habitat‐former and associated community relationships use broad‐scale classifications to group habitat‐formers according to identity or gross morphology. Trait‐based approaches instead measure traits at the level of the individual and in doing so allow for predictions that are not constrained to taxonomic groups. By measuring at the level of the individual, trait‐based approaches have the potential to capture not only interspecific variability, but also the intraspecific variation that is often ignored by traditional approaches. Trait‐based approaches may therefore provide a novel way to link the characteristics of habitat‐formers to ecosystem functioning. Here we quantified inter‐ and intraspecific variation in six macroalgal species and tested the relative importance of morphological traits and species identity in predicting the abundance of associated fauna. All species of macroalgae displayed substantial intraspecific morphological variation. Morphological traits were more important than species identity in predicting epifaunal abundances. Total surface area was the most important trait when predicting total abundance per thallus, whilst mean frond length was the most important predictor for abundance per gram algal biomass. This suggests that traits that describe the quantity of available habitat were the most important predictors of community abundance, but the shape or architecture of the habitat also contributes to structuring these communities. Our results indicate that trait‐based approaches may be more useful than traditional species‐based approaches when predicting the abundances of fauna associated with habitat‐forming species. A free Plain Language Summary can be found within the Supporting Information of this article.

中文翻译：

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水下森林中的栖息地变异：使用基于特征的方法来预测相关群落。

通过提供食物、生活空间和减少生物和非生物压力，栖息地形成者支持不同的社区。然而，介导它们对相关生物的价值的特征并不总是很清楚。对栖息地前身和相关社区关系的传统评估使用大尺度分类，根据身份或总体形态对栖息地前身进行分组。相反，基于特征的方法在个体水平上测量特征，这样就可以进行不受分类群体限制的预测。通过在个体水平上进行测量，基于特征的方法不仅有可能捕获种间变异，还可以捕获传统方法经常忽略的种内变异。因此，基于特征的方法可以提供一种将栖息地形成者的特征与生态系统功能联系起来的新方法。在这里，我们量化了六个大型藻类物种的种间和种内变异，并测试了形态特征和物种同一性在预测相关动物群丰度方面的相对重要性。所有种类的大型藻类都显示出大量的种内形态变异。在预测动物群落丰度方面，形态特征比物种特征更重要。在预测每个藻体的总丰度时，总表面积是最重要的性状，而平均叶长是每克藻类生物量丰度的最重要预测因子。这表明描述可用栖息地数量的特征是群落丰度的最重要预测因子，但栖息地的形状或建筑也有助于构建这些社区。我们的结果表明，在预测与栖息地形成物种相关的动物群丰度时，基于特征的方法可能比传统的基于物种的方法更有用。可以在本文的支持信息中找到免费的普通语言摘要。