Contribution of Leaf Litter to Nutrient Export during Winter Months in an Urban Residential Watershed
| Autor: | Benjamin D. Janke, Kathrine L. Kemmitt, Anika R. Bratt, Adam C. Worm, Jacques C. Finlay, Sarah E. Hobbie |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Hydrology
Watershed 010504 meteorology & atmospheric sciences Nitrogen Minnesota Stormwater Phosphorus General Chemistry 010501 environmental sciences Plant litter 01 natural sciences Nutrient Rivers Environmental Chemistry Environmental science Water quality Cities Eutrophication Nonpoint source pollution Overwintering Environmental Monitoring 0105 earth and related environmental sciences |
| Zdroj: | Environmental Science & Technology. 51:3138-3147 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/acs.est.6b06299 |
| Popis: | Identification of nonpoint sources of nitrogen (N) and phosphorus (P) in urban systems is imperative to improving water quality and better managing eutrophication. Winter contributions and sources of annual N and P loads from urban watersheds are poorly characterized in northern cities because monitoring is often limited to warm-weather periods. To determine the winter export of N and P, we monitored stormwater outflow in a residential watershed in Saint Paul, Minnesota during 2012-2014. Our data demonstrate that winter melt events contribute a high percentage of annual N and P export (50%). We hypothesized that overwintering leaf litter that is not removed by fall street sweeping could be an important source to winter loads of N and P. We estimated contributions of this source by studying decomposition in lawns, street gutters, and catch basins during two winters. Rates of mass and N loss were negligible during both winters. However, P was quickly solubilized from decomposing leaves. Using mass balances and estimates of P leaching losses, we estimated that leaf litter could contribute 80% of winter total dissolved phosphorus (TDP) loading in this watershed (∼40% of annual TDP loading). Our work indicates that urban trees adjacent to streets likely represent a major source of P pollution in northern cities. Management that targets important winter sources such as tree leaves could be highly effective for reducing P loading and may mitigate eutrophication in urban lakes and streams in developed cities. |
| Databáze: | OpenAIRE |
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