Abstract
Streams integrate biogeochemical processes operating at broad to local spatial scales and long term to short term time scales. Humans have extensively altered those processes in North America, with serious consequences for aquatic ecosystems. We collected data on Upper Tennessee River tributaries in North Carolina to: (1) compare landuse and landscape geomorphology with respect to their ability to explain variation in water quality, sedimentation measures, and large woody debris; (2) determine if landscape change over time contributed significantly to explaining present stream conditions; and (3) assess the importance of spatial scale in examining landuse influences on streams. Stream variables were related to both landuse and landscape geomorphology. Forest cover accounted for the most variation in nearly all models, supporting predictions of nutrient enrichment, thermal pollution, and sedimentation caused by landscape disturbance. Legacy effects from past catchment disturbance were apparent in sedimentation measures. Nitrogen and phosphorus concentrations, as well as stream temperature, were lower where riparian buffers had reforested. Models of stream physicochemistry fit better when predictors were catchment wide rather than more localized (i.e., within 2 km of a site). Cumulative impacts to streams due to changes in landuse must be managed from a watershed perspective with quantitative models that integrate across scales.
Original language | English (US) |
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Pages (from-to) | 1379-1392 |
Number of pages | 14 |
Journal | Journal of the American Water Resources Association |
Volume | 38 |
Issue number | 5 |
DOIs | |
State | Published - Oct 2002 |
Bibliographical note
Funding Information:The authors are grateful to the financial support from Natural Science Foundation of China (Grant No.50572047) and the Excellent Young Teachers Research Program of Beijing Institute of Technology (2007Y0206).
Keywords
- Catchment landuse
- Highland water quality
- Nonpoint source pollution
- North Carolina, USA
- Sedimentation
- Southern Appalachian Mountains
- Watershed management