In fast-flowing streams, caddisfly larvae are responsible for processes that collectively determine the efficiency with which the detritivore community is able to decompose autochthonous and allochthonous detritus. This ecosystem function ensures high water quality and represents a precious service for resident rural communities. The analysis of δ¹³C and δ¹⁵N in eight caddisfly taxa from a mid-mountain stream evidenced a remarkable complementarity in their feeding preferences. An aquatic moth mimicking the caddis mode of life was also included in the survey and its feeding niche appeared to be in between the one of caddis taxa. Moderate niche overlap was interpreted in terms of low functional redundancy, implying that in case of a reduction in diversity, no taxon could be a perfect substitute for another, with a loss of functional efficiency. Low redundancy could be caused by niche segregation due to avoidance of competition/interference between taxa. The broad range of δ¹³C and δ¹⁵N described in this study warns against attributing single δ¹³C and δ¹⁵N to Trichoptera as a group, or even to single families. These results contribute to the still poorly known distribution of East African caddisflies and to the characterisation of feeding preferences of Afrotropical trichopteran larvae.

中文翻译：

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共享半山溪流的石蛾之间的低冗余度

在快速流动的溪流中，石蚕幼虫负责共同决定碎屑动物群落分解本地和外来碎屑的效率的过程。这种生态系统功能确保了高水质，并为农村社区提供了宝贵的服务。对来自中山溪流的八个石蚕类群的 δ ¹³ C 和 δ ¹⁵ N的分析证明了它们的摄食偏好具有显着的互补性。调查中还包括一种模仿石蚕生活模式的水蛾，其摄食生态位似乎介于石蚕类群之间。适度的生态位重叠被解释为低功能冗余，这意味着在多样性减少的情况下，没有一个分类单元可以完美替代另一个分类单元，同时会损失功能效率。低冗余可能是由于避免类群之间的竞争/干扰而造成的生态位隔离造成的。^{本研究中描述的 δ 13} C 和 δ ¹⁵ N的广泛范围警告不要将单个 δ ¹³ C 和 δ ¹⁵ N 归因于毛翅目作为一个群体，甚至归因于单个科。这些结果有助于了解仍鲜为人知的东非石蛾分布，并有助于描述非洲热带毛翅目幼虫的摄食偏好特征。