Do isolation and local habitat jointly limit the structure of stream invertebrate assemblages

摘要: Summary 1. Both local and regional processes simultaneously control species assemblages depending on spatial habitat configuration. In dendritic networks like streams, the unique arrangement of habitats produces various combinations size isolation. Stream invertebrate could therefore be controlled by different processes, their location in network. 2. Using quantile regression, we investigated how size, environmental conditions isolation influenced variation assemblage composition. Adult Trichoptera benthic macroinvertebrate were represented non-metric multidimensional scaling (NMDS) ordination scores, as conditions, four headwater stream New Zealand. 3. With increasing there was a decrease composition (NMDS scores) both adult macroinvertebrates. This relationship between related to at upper limit variability lower variability, for assemblages, indicating joint controls assemblages. 4. The relationships neighbours, based community similarity differed macroinvertebrates Trichoptera. For larger stream, more similar neighbouring whereas no consistent difference structuring attributed contrasting influences linked dispersal modes adults larvae. However, because are not independent, influence life stage distribution is difficult determine (i.e. it essentially ‘chicken egg’ argument). 5. Overall, our approach using regression evaluate responses, rather than regressions means, has highlighted importance assemblages. Furthermore, have provided evidence network interactions stages