Authors: Taiping Zhang Xinyu Huang Yue Yang Yuelin Li Randy A Dahlgren
Publish Date: 2015/09/16
Volume: 23, Issue: 2, Pages: 1552-1564
Abstract
Spatial and temporal variability in nitrous oxide and methane emissions were quantified in three seasons using closed chambers in three riparian zone locations of three branches of the Pearl River Guangzhou China The sampling sites were selected in a rapidly developing urban area of Guangzhou and represented a pollution gradient The results show that urban riparian landscapes can be large source areas for CH4 and N2O with fluxes of −0035 ∼ 3230 mg m−2 h−1 and −549 ∼ 3731 μg m−2 h−1 respectively River water quality sediment texture and NH4N and NO3N concentrations correlated with N2O and CH4 emission rates The riparian zones of the more seriously polluted tributaries showed higher greenhouse gas fluxes than that of the less polluted main stem of the Pearl River Rain events increased emissions of CH4 by 65 ∼ 213 times and N2O by 22 ∼ 57 times The lower concentrations of heavy metals increased the activity of denitrifying enzymes while inhibited the methane producing pathways This work demonstrates that rapidly developing urban areas are an important source of greenhouse gas emissions which is conditioned by various environmental factorsThis study was supported by the Science and Technology Program of Guangzhou Guangdong China 2014 J4100020 the Knowledge Innovation Program of the Chinese Academy of Sciences Grant No KZCX2YWGJ01 National Science Foundation of China Grant No 31170375 and the Project of the National Ecological System Network of Dinghushan Station of China The authors wish to thank their laboratory team for providing assistance in sample collection and analysis and the work in the University of California Davis of Dr Taiping Zhang which was partly sponsored by a visiting scholar fellowship from the Chinese Ministry of Education and National Science Foundation of People’s Republic of China
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