Higher enrichment is necessary for significant accrual of Cladophora filaments compared to diatom-dominated periphyton. The positive effect of nutrients is observed in invertebrate and fish biomass, as well as algal biomass. Even though responses of algal and invertebrate biomass to nutrient concentrations were relatively linear, responses of individual species occurred at nutrient thresholds. These indicators should be relatively transferable among ecoregions. Changes in invertebrate species composition were relatively insensitive to nutrient concentrations.
Resource thresholds and stream ecosystem sustainability.
Diatom indicators of stream and wetland stressors in a risk management framework. A habitat matrix conceptual model for stream periphyton. Stevenson RJ, Pan Y. Assessing ecological conditions in rivers and streams with diatoms. Cambridge University Press, Cambridge, UK, 1999. Spatial patterns and ecological determinants of benthic algal assemblages in Mid-Atlantic Highland streams.