Despite the importance of shredders in organic matter processing in streams, information about the habitat specificities of different taxa is scarce. Herein, we evaluated the habitat preferences of invertebrate shredders in tropical forest streams. A total of 72 leaf patches were sampled in three Atlantic Forest streams (SE Brazil). For each sample, 20 environmental variables were measured, including water properties and characteristics of the leaf patch. We used an Outlying Mean Index analysis to evaluate the niche breadth and overlap of each taxon found as well as habitat preferences. In total, we found 14 shredder taxa in 68 leaf patches, and the gradient of environmental conditions influenced the distribution of most taxa. Considering taxa that occurred in atypical habitats in the study sites, Blaberidae (semiaquatic cockroaches) and Trichodactylus fluviatilis (Decapoda) showed niche segregation, while Macrobrachium potiuna (Decapoda), Tupiperla (Plecoptera), and Nectopsyche (Trichoptera) showed niche overlap. On the other hand, Heterelmis (Coleoptera), Stenochironomus (Diptera), Phylloicus major, and Triplectides gracilis (Trichoptera) occurred in typical habitats. These results showed that shredder taxa had different habitat preferences. The observed differences in niche breadths and habitat specificities among taxa probably result in different leaf processing rates across leaf patches in Atlantic Forest streams.

中文翻译：

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热带森林溪流中无脊椎动物切碎机的利基宽度：哪些分类群限制了栖息地偏好？

尽管粉碎机在溪流中的有机物加工中很重要，但关于不同分类群栖息地特性的信息却很少。在此，我们评估了热带森林溪流中无脊椎动物切碎机的栖息地偏好。在三个大西洋森林溪流（巴西东南部）中对总共 72 个叶斑进行了采样。对于每个样本，测量了 20 个环境变量，包括水的特性和叶斑的特征。我们使用离群平均指数分析来评估发现的每个分类群的生态位宽度和重叠以及栖息地偏好。我们总共在 68 个叶斑中发现了 14 个粉碎类群，环境条件的梯度影响了大多数类群的分布。考虑到发生在研究地点非典型栖息地的分类群，Blaberidae (半水生蟑螂) 和 Trichodactylus fluviatilis (Decapoda) 显示生态位分离，而 Macrobrachium potiuna (Decapoda)、Tupiperla (Plecoptera) 和 Nectopsyche (Trichoptera) 显示生态位重叠。另一方面，异翅目（鞘翅目）、狭长目（双翅目）、大叶螟和纤细三叶虫（毛翅目）出现在典型的生境中。这些结果表明切碎机类群具有不同的栖息地偏好。观察到的类群之间生态位宽度和栖息地特异性的差异可能导致大西洋森林溪流中不同叶斑的叶片加工率不同。Stenochironomus (Diptera), Phylloicus major, 和 Triplectides gracilis (Trichoptera) 出现在典型的栖息地。这些结果表明切碎机类群具有不同的栖息地偏好。观察到的类群之间生态位宽度和栖息地特异性的差异可能导致大西洋森林溪流中不同叶斑的叶片加工率不同。Stenochironomus (Diptera), Phylloicus major, 和 Triplectides gracilis (Trichoptera) 出现在典型的栖息地。这些结果表明切碎机类群具有不同的栖息地偏好。观察到的类群之间生态位宽度和栖息地特异性的差异可能导致大西洋森林溪流中不同叶斑的叶片加工率不同。