Diatom Assemblages Alterante Stable State Hypothesis Productivity Threshold
Abstract:
I tested the hypothesis that the response of stream ecosystems in the mid Atlantic region to nutrient enrichment can be initially predicted by the alternative stable states hypothesis. A survey of 43 third order streams showed that increasing agricultural land use (and associated in-stream nutrient concentrations) corresponded with higher stream productivity. Taxonomic composition at the low and high end of the productivity gradient support diatom species with a low versus higher specificity for phosphorus and nitrogen, respectively. These transiting diatom communities could be the link (pathway) in which these alternate productive stream states occur.
