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The release of phosphorus from sediment into water in subtropical wetlands: a warming microcosm experiment
Author(s) -
ZhiJian Zhang,
ZhaoDe Wang,
Holden Joseph,
XinHua Xu,
Hang Wang,
JingHua Ruan,
Xin Xu
Publication year - 2011
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.8105
Subject(s) - microcosm , environmental science , wetland , sediment , ecology , global warming , environmental chemistry , phosphorus , biomass (ecology) , water quality , hydrology (agriculture) , climate change , chemistry , geology , biology , paleontology , geotechnical engineering , organic chemistry
Global warming poses a great threat to wetland ecological stability and water quality improvement. In this paper, we sampled six types of wetlands representing different kinds of land utilisation around the TaiHu Lake Basin in southeast China. An outdoor computerized microcosm was set up in May 2008 to simulate climate scenarios of ambient temperature (control) and a warmed ambient temperature (+5 °C) using a novel minute‐scale daily and seasonal temperature manipulation technology. The 18‐month incubation indicated that warming impaired the ecological sink of sediment (fixing P from porewater) while strengthening the role of the ecological source, moreover, the rate of P release from sediment into porewater (19–113% for total phosphorus) was much stronger than from top sediment into overlying water. Warming enhanced the activity of neutral and alkaline phosphatases for P‐deficient wetland sediments and neutral phosphatases for P‐rich sediments, at the 14th month of incubation. A significant increase in total phospholipid fatty acids (PLFAs) occurred under warming in sediments with relatively low levels of PLFAs, but bacterial abundance in the sediment biomass tended to decrease (18%) along with an increase (4·5%) of the fungi‐to‐bacteria ratio. The variations of carbon consumption and availability indicated by measured dissolved organic carbon in sediment may have contributed to P release from sediments to water. Copyright © 2011 John Wiley & Sons, Ltd.