SS3.05 Land-use, Groundwater and Lotic Ecosystems
Date: Monday, June 10, 2002
Location: Colwood
 
O'BrienPJ, Louis Calder Center- Biological Station, Fordham University, PO Box 887, , Armonk, NY 10504, USA, pobrien@fordham.edu
Wehr, J, D, Louis Calder Center- Biological Station, Fordham University, PO Box 887, , Armonk, NY 10504, USA, wehr@fordham.edu
Perrone, A, A, Louis Calder Center- Biological Station, Fordham University, PO Box 887, , Armonk, NY 10504, USA, aperrone@fordham.edu
 
LAND USE AND URBANIZATION EFFECTS ON BENTHIC ALGAL COMMUNITIES IN STREAMS IN SOUTHEAST NEW YORK STATE.
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Land use and population density were considered as possible ultimate factors affecting stream algal communities at varying distances from New York City. Stream properties (proximate variables) and benthic algal communities were studied in 36 wadable 1st to 3rd order streams within a 6000 sq. km area in southeast New York. Conductivity (r = -0.722, P < 0.00001), [Mg] (r = -0.653, P = 0.00002), benthic AFDM per surface area (r = -0.485, P = 0.00314) were positively correlated with urbanization, as were other water chemistry, physical, and benthic algal variables. Conductivity and [Mg] were most strongly correlated with multiple benthic algal variables (r = 0.323 to 0.737, P = 0.05 to < 0.00001). Multiple linear regression models for the benthic algal variables indicated that stream [Ca], [Mg], [Si] and pH, all of which are negatively correlated with distance from New York City, were found to be the best predictors of benthic algal variables measured. A spatially explicit (GIS) model of these data suggests that distance from an urban area can have a profound effect on benthic algal communities in streams.