Variation in Leaf Decomposition Rates in Two Adjacent Urban Stream Reaches

Abstract

By Joshua Harris, Biology, Environmental Studies

Advisor: Michael Booth

Presentation ID: AM_ATRIUM06

Abstract: The input of organic matter into urban stream environments from the surrounding environment and its breakdown is an important piece of the aquatic food web and is affected by both biotic and abiotic factors within the system. In this study we collected data on the rates of decomposition of maple leaves in both the main and east fork of the Mill Creek at Twin Creeks Preserve. We expected the exclusion of invertebrates to lower breakdown rates and that the east site would be more productive, with higher breakdown rates. Our results show that these two systems are significantly different from one another. The east fork site, which is downstream of a wastewater treatment facility, exhibits significantly higher temperature and conductivity with an observed macroinvertebrate community many times larger than that of the main fork site. Preliminary results suggest that the breakdown of leaves at the east fork site occurs at a rate significantly greater than at the main fork site. Further understanding the web of interactions that contribute to the processing of organic matter in urban streams is vital to the maintenance of natural systems in highly urbanized and industrial areas like the Mill Creek.