Relationships between Size Structure of Invertebrate Assemblages and Trophy and Substrate Composition in Streams

摘要: Nine stream sites, spanning the range of water total phosphorus concentrations ([TP]) found in Eastern Ontario and Western Quebec, were sampled June 1992 to describe how size distribution invertebrates varied along a nutrient gradient among substrate categories ranging from sand small boulders. Despite clear differences taxonomic composition shape was remarkably similar all sites. Substrate affected overall abundance more than their distribution. Overall density peaked on fine coarse gravel lower Total highest eutrophic sites ([TP] > 40 μg/L), although only organisms larger 1 mm (approximately μg dry mass) showed higher abundances richer The increase invertebrate with increasing concentration suggests that these streams are limited. Animals smaller long account...