Effects of water and sediment regulation on net ecosystem metabolism in the Yellow River estuary, China
Successful artificial hydrological regulation or environmental flow assessments for ecosystem protection require an accurate understanding of the linkages among flow events and biotic responses. We analyzed spatial and temporal variation in net ecosystem metabolism (NEM) to explore the ecosystems functional responses to hydrologic alterations caused by the regulation of water and sediment flows in the Yellow River estuary, China. We measured 11 environmental properties of the water column over a 2-year period from April 2009 to September 2010. Significantly spatial and temporal variation in enwronmental parameters and NEM were observed in the Yellow River estuary. The estuary was dominated by heterotrophic processes before and after water and sediment regulation. Mean aquatic NEM was -2.215 mgO2 L-1d-l, reflecting a reliance on extemal sources of organic matter in the Yellow River estuary. High-amplitude flood pulses created by water and sediment regulation caused the estuarine water column to become more heterotrophic. Turbidity was a particularly important factor that influenced the variations in the metabolic balance in the upper and middle parts of the estuary, as well as salinity and chemical oxygen demand, but it was not true in the far estuary. Water discharges are related to aquatic NEM, but whether flood pulses will mainly affect GPP or ER depend on local conditions. Increasing turbidity reduces the light penetration, limits the photosynthesis and stimulates the ER, leading to more heterotrophic aquatic environment. Artificial hydrological regulation strategies should therefore carefully consider the impacts of turbidity variations caused by high-amplitude flood pulse on the estuarine ecosystems metabolic balance, especially in estuaries with a high sediment concentration.
Net ecosystem metabolism Ecosystem response Artificial hydrological regulation Turbidity Yellow River estuary
Xiaomei Shen Tao Sun FangFang Liu Jing Xu Aiping Pang
State Key Laboratory of Water Environment Simulation, School of Environment. Beijing Normal University, No.19, Xinjiekouwai Street, Haidian District, Beijing 100875, China
国际会议
The 3rd Biennial ISRS Symposium Achieving Healthy and Viable Rivers (ISRS)第3届国际河流大会
北京
英文
690-703
2013-08-05（万方平台首次上网日期，不代表论文的发表时间）