Spatial and temporal variability of diatom and macroinvertebrate communities: How representative are ecological classifications within a river system?

Evaluation of river condition is complicated by dynamic relationships between river assemblages and their environment. We assessed variation of ecological status classifications of stream diatom and macroinvertebrate communities within a boreal river system. We specifically examined whether results of ecological classifications are concordant across taxonomic groups and among main channel and headwater side tributaries of this river system. We further assessed whether ecological classifications are stable from year to year and whether classifications show predictable relationships to major stressor gradients. The estimated ecological condition varied considerably among and between reaches o…