| Abstract: | Patterns of stream benthic algal assemblages along urbanization gradients were investigated in three metropolitan areas-Boston (BOS), Massachusetts; Birmingham (BIR), Alabama; and Salt Lake City (SLC), Utah. An index of urban intensity derived from socioeconomic, infrastructure, and land-use characteristics was used as a measure of urbanization. Of the various attributes of the algal assemblages, species composition changed along gradients of urban intensity in a more consistent manner than biomass or diversity. In urban streams, the relative abundance of pollution-tolerant species was often higher than in less affected streams. Shifts in assemblage composition were associated primarily with increased levels of conductivity, nutrients, and alterations in physical habitat. Water mineralization and nutrients were the most important determinants of assemblage composition in the BOS and SLC study areas; flow regime and grazers were key factors in the BIR study area. Species composition of algal assemblages differed significantly among geographic regions, and no particular algal taxa were found to be universal indicators of urbanization. Patterns in algal biomass and diversity along urban gradients varied among study areas, depending on local environmental conditions and habitat alteration. Biomass and diversity increased with urbanization in the BOS area, apparently because of increased nutrients, light, and flow stability in urban streams, which often are regulated by dams. Biomass and diversity decreased with urbanization in the BIR study area because of intensive fish grazing and less stable flow regime. In the SLC study area, correlations between algal biomass, diversity, and urban intensity were positive but weak. Thus, algal responses to urbanization differed considerably among the three study areas. We concluded that the wide range of responses of benthic algae to urbanization implied that tools for stream bioassessment must be region specific. ?? 2005 by the American Fisheries Society. |
| Genre: | Article |
| ProdID: | 70027955 |
| Citation Author: | Potapova, M.; Coles, J. F.; Giddings, E. M. P.; Zappia, H. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 359 |
| Citation Issue: | 47 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | American Fisheries Society Symposium |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 27 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | A comparison of the influences of urbanization in contrasting environmental settings on stream benthic algal assemblages; 2005; Article; Journal; American Fisheries Society Symposium; Potapova, M.; Coles, J. F.; Giddings, E. M. P.; Zappia, H. |
| Citation Start Page: | 333 |
| Citation Volume: | 2005 |
| Citation Year: | 2005 |
| Type: | citation/reference |
| Text: | A comparison of the influences of urbanization in contrasting environmental settings on stream benthic algal assemblages; 2005; Article; Journal; American Fisheries Society Symposium; Potapova, M.; Coles, J. F.; Giddings, E. M. P.; Zappia, H. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sat, 1 Jan 2005 00:00 -0600 |
| Publisher: | |
