Leaching and Decomposition of Leaves from Baltimore Urban Area - Implications for Urbaniation and Gloabl Warming on carbon cycle

Shuiwang Duan, University of Maryland, sduan@umd.edu (Presenter)
Sujay Kaushal, University of Maryland, skaushal@umd.edu

Urban watersheds, where 80% of U.S. population dwell, are among the most vulnerable regions for global climate changes. Increasing tree and vegetative cover is a simple and effective way to reduce urban high temperatures and heat waves. Tree planting in riparian zone is also part of many stream restoration projects for water quality improvement and flood control. However, it is still controversial what tree species need to be planted to meet multiple purposes. In this study, dried leaves which are collected from Gwynns Fall riparian zone were leached at 4 and 20 degree C for 90 hours to measure their production of dissolved organic carbon (DOC) and nutrients at different temperature settings. The leaf leachates were then decomposed at the two temperatures to examine their stability and production of CO2. Results show that, maple leaves were highest in DOC release, followed by grape vine, willow, elm and algae, and the pine had the lowest value. DOM was relatively depleted in total nitrogen and phosphorus in leachates from grape vine or pine. Rate of DOC release was significantly enhanced by incubating temperature, and also affected by vegetation type that differed in organic matter quantity and quality. Approximately 23-92% of DOC in undiluted leachates was utilized in 252 hours, and the rate of utilization was also affected by incubating temperature and leaf types. Utilizations of total nitrogen and phosphorus were relatively smaller, likely owing to microbial nutrient recycling. Changes in stream vegetation type and temperature, as a result of urbanization and global warming, may greatly affect the release of dissolved organic matter and carbon dioxide from leaves in urban area thus influences global carbon cycle.

Presentation Type:  Poster

Session:  Global Change Impact & Vulnerability   (Tue 11:30 AM)

Associated Project(s): 

• Kaushal, Sujay: Understanding and Forecasting Impacts of Climate Change and Land Use on Terrestrial Carbon Fluxes in Coastal Watersheds ...details

Poster Location ID: 172