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Communication at the NABS Annual meeting, Keystone, 2000
(127) CAN DIATOMS REFLECT IMPACTS OF URBANIZATION ON STREAMS?.
C. Walker. Environmental Sciences and Resources, Portland State University, Portland, OR 97207, USA
We compared diatom assemblages between an urban and rural stream with comparable stream characteristics (e.g. gradient, size). Stream sites were sampled for diatoms concurrently with environmental variables. Diatom assemblages at urban sites were dominated by Rhoicosphenia curvata (22%), Achnanthes deflexa (18%), Cocconeis placentula (12%), and Nitzschia inconspicua (8%). Rural sites were dominated by A. deflexa (45%), C. placentula (11%), R. curvata (9%), and A. lanceolata (6%). Conductivity, total nitrogen (TN), total phosphorus (TP), and percent fines were significantly different between urban and rural sites (p<0.05). Canonical correspondence analysis showed that diatom species assemblages correlated with TP, TN, and conductivity. Our results suggest that diatom species assemblages can be used to reflect impacts of urbanization on streams.
Presented at 2:30 PM on Tuesday, May 30, 2000 in Bioindicators and Rapid Bioassessments I
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