Effects of environmental factors and predation on benthic communities in headwater streams

摘要: Structure and composition of benthic macroinvertebrate assemblages were investigated during three consecutive years in six headwater streams that exhibit a high variation environmental conditions, habitat structure predatory pressure. We examined whether the abundance functional feeding groups could be best predicted by predators some chemical variables. Mean density biomass varied significantly throughout study area. Stepwise multiple regression analyses revealed both was influenced primarily features water. Shredder scraper also features, scrapers increasing deeper localities at lower altitudes with abundant macrophytes. The invertebrates related to prey. An influence fish predation on invertebrate communities not observed streams. finding undisturbed are mainly affected water chemistry variables irrespective clearly highlight sensitivity changes their role as indicators for bioassessment.