Institute of Ecosystem Studies

2007 BES Annual Meeting Presentation and Poster Abstracts

Nitrogen and root dynamics in urban forest patches
Zhu, Weixing
Co-Authors: B.A. Egitto and W.X. Zhu
Abstract: Urban remnant forests are receiving high levels of nitrogen (N) deposition, especially in the form of nitrate. Furthermore, environmental interaction at the forest edge may affect N dynamics and plant nutrient use differently than in the forest center. We selected four forest patches on the State University of New York- Binghamton campus. CW and NW are relatively large and WG and FA are small. In addition we sampled the Nature Preserve (NP), composed of only center, and a small, edge only site (SW). Soil cores were taken underneath the Quercus rubra, on four sampling dates in 2004. Percentage SOM at the edge location was significantly lower than the center. FA and WG had %SOM significantly lower than NP, while CW and NW are not significantly different from NP. Soil moisture followed a similar pattern to SOM with the two highly correlated (r2=0.604). Both N mineralization and nitrification were higher in the center than in the edge (P<0.001). WG and FA were the only two had significantly higher nitrification rates (P<0.001), and significant extractable NO3-N (P<0.001). The edge areas had higher root biomass (P<0.001), but lower tissue N and P concentrations (P=0.002, P<0.001) than in the center. Root biomass was lowest in WG, a site with the highest N mineralization and nitrification rates (P<0.001). These findings suggest that smaller forest patches are more affected by urban surroundings than the larger patches, and forest edges and centers are differentially affected with consequences on N biogeochemistry and plant response.