Baltimore Ecosystem Study Institute of Ecosystem Studies

2010 BES Annual Meeting Presentation and Poster Abstracts

Organic carbon concentrations in riparian soils along a suburban to urban gradient in Baltimore, Maryland
Noonan, Emma
Co-Authors: E. Noonan, R. Pouyat, I. Yesilonis

Abstract: Urban riparian zones provide important ecosystem functions and habitat for many plant and animal species. Urban development can greatly alter these functions yet these effects are not well understood. Possible effects from urbanization could be caused by decreases in litter quality in the riparian zone, increased scouring of bank sediments, lower water tables leading to increases in decomposition, among others. Here, we present preliminary results on how organic carbon in riparian soils is affected by urbanization. We took soil cores at 22 cross sectional transects along stream reaches of the Gwynns Falls Watershed in Baltimore, Maryland and analyzed them for organic carbon. We determined percent carbon compared to several landscape variables: percent impervious in the drainage area, percent forested, and size of drainage area. Percent carbon was not correlated to these variables when the comparison included all stream orders (2nd - 4th ), however a subset of transects in 4th order streams (11 of the 22 transects) were significantly correlated to percent impervious, size of drainage area, and percent forest.. Moreover, there was an indirect relationship between the size of the drainage area and soil carbon. Finally, % impervious was significantly different between the lower watershed with 31.5% and the middle (24.9%) and upper (14.4%) watersheds. By contrast, the percent carbon was higher in the upper portions of the watershed. These results indicate urban land use could have a significant effect on the %C in the riparian soils of the Gwynns Falls watershed, at least for 4th order stream reaches. Factors such as % impervious often have large impacts on ecosystem function and here we see the possible effect on soil organic carbon.