Data from: The shape of success in a turbulent world: wave exposure filtering of coral reef herbivory

While environmental filters are well-known factors influencing community assembly, the extent to which these modify species functions, and entire ecosystem processes, is poorly understood. Focusing on a high-diversity system, we ask whether environmental filtering has ecosystem-wide effects beyond community assembly. We characterise a coral reef herbivorous fish community for swimming performance based on ten functional traits derived from fish morphology. We then investigate whether wave exposure modifies the functional make-up of herbivory, and the absolute and relative feeding frequency of distinct feeding functional groups. Herbivorous fish species conformed to either laterally compressed or fusiform body plans, which differ in their morphological design to minimise drag. High wave exposure selectively limited the feeding function of the deepest body shapes with highest caudal thrust efficiency, and favoured fusiform bodies irrespective of pectoral fin shape. Traditionally recognised herbivore feeding functional groups (i.e. grazers–detritivores and scrapers–small excavators) differed in swimming performance, and in their capacity to feed consistently across levels of wave exposure. We therefore emphasise the distinctness of their ecological niche and functional complementarity. Species within the same feeding functional group also had contrasting responses to wave exposure. We thereby reveal a further ecological dimension of niche partitioning, and reiterate the risk of assuming functional redundancy among species with a common feeding mode. Contrasting responses of species within feeding functional roles (i.e. response diversity) allowed the preservation of critical trophic functions throughout the gradient (e.g. macroalgal browsing), and likely explained why overall levels of herbivory were robust to filtering. Whether ecosystem functioning will remain robust under the additive effects of environmental stress and human-induced disturbances remains to be tested.尽管环境过滤（environmental filter）是影响群落组装的公认因素，但这些因子对物种功能乃至整个生态系统过程的调控程度仍鲜为人知。 本研究以高多样性生态系统为研究对象，旨在探究环境过滤是否会对群落组装之外的生态系统产生全域影响。我们基于鱼类形态学衍生出的10项功能性状，对珊瑚礁植食性鱼类群落的游泳性能进行了表征；随后探讨了波浪暴露是否会改变植食作用的功能组成，以及不同摄食功能类群的绝对与相对摄食频率。 植食性鱼类的体型可分为侧扁体型（laterally compressed body plan）与纺锤体型（fusiform body plan）两类，二者通过差异化的形态设计以降低水流阻力。高波浪暴露会选择性地限制那些体型最深、尾推效率最高的类群的摄食功能，而无论胸鳍形态如何，均更青睐纺锤体型。 传统认知中的植食性鱼类摄食功能类群（即牧食者-腐食者与刮食者-小型挖掘者）在游泳性能以及在不同波浪暴露水平下持续摄食的能力上均存在差异。因此，本研究强调了这些类群生态位的独特性与功能互补性。 同一摄食功能类群内的物种对波浪暴露的响应也存在显著差异。这一发现揭示了生态位分化的又一重生态维度，同时也重申了假定具有相同摄食模式的物种存在功能冗余的风险。 摄食功能类群内物种的差异化响应（即响应多样性（response diversity））使得关键营养功能在整个波浪暴露梯度上得以保留（例如大型藻类牧食），这也解释了为何植食作用的整体水平对环境过滤具有较强的抵抗力。而在环境胁迫与人类活动干扰的叠加效应下，生态系统功能是否仍能保持稳定，仍有待进一步验证。