You are here:
DIATOM INDICES OF STREAM ECOSYSTEM CONDITIONS: COMPARISON OF GENUS VS. SPECIES LEVEL IDENTIFICATIONS
Citation:
Hill, B H., R. J. Stevenson, AND Y. Pan. DIATOM INDICES OF STREAM ECOSYSTEM CONDITIONS: COMPARISON OF GENUS VS. SPECIES LEVEL IDENTIFICATIONS. Presented at North American Benthological Society, Duluth, MN, May 25-28, 1999.
Description:
Diatom assemblage data collected between 1993 and 1995 from 233 Mid-Appalachian streams were used to compare indices of biotic integrity based on genus vs. species level taxonomy. Thirty-seven genera and 197 species of diatoms were identified from these samples. Metrics included in the diatom IBIs included taxa richness, percent relative abundance (PRA) of the dominant diatom taxa, PRA of acidophilic diatoms, PRA of eutrophic diatoms, and PRA of motile diatoms. Diatom richness was positively, though weakly, correlated with indicators of stream eutrophication (total nitrogen, total phosphorus, chloride, total suspended solids) for both the genus and species level metrics. The PRA dominant taxa was significantly related to total P for genus level taxonomy and with total P, turbidity, and pH for the species level metric. The PRA of acidophilic diatoms was significantly correlated with pH, dissolved Al and Mn for both genus and species level metrics. The PRA of eutrophic species was negatively correlated with pH for the genus level metric and with total P and turbidity for the species level metric. Motile diatoms, at both the genus and species level of taxonomy, were significantly correlated with total N, watershed disturbances, and the percent of the watershed in natural vegetation. Overall, genus and species level diatom indices of biotic integrity performed similarly, and for most assessment and monitoring goals, genus level taxonomy may by sufficient.