丹江口水庫是南水北調(diào)中線工程的水源地，其水質(zhì)狀況關(guān)系著中線調(diào)水工程沿線地區(qū)的用水安全。水庫消落區(qū)濕地是水體與陸地之間的過渡帶，具有較為豐富的生物多樣性和獨特的生態(tài)服務(wù)功能,。丹江口水庫消落區(qū)濕地是控制庫區(qū)污染入庫的最后一道防線，對于削減非點源污染物入庫總量,、保障水庫水質(zhì)安全起著非常重要的作用,。
中科院武漢植物園劉文治博士、張全發(fā)研究員和劉貴華研究員通過吸附-解吸附實驗發(fā)現(xiàn),，丹江口水庫消落區(qū)濕地的土壤具有較高的磷吸附容量,，每千克土壤的最大磷吸附值可達(dá)771.3 mg，但秋冬季水位的上升會導(dǎo)致24.11%的土壤吸附磷重新釋放到水體中去,。通過乙炔抑制-氣相色譜實驗,，劉文治等還發(fā)現(xiàn)消落區(qū)濕地不同植物群落土壤的反硝化能力存在著顯著性的差異，水蓼和藨草群落土壤的反硝化能力要顯著高于其它群落,。植物生物量,、植被蓋度與反硝化能力呈顯著的正相關(guān)關(guān)系。
研究結(jié)果表明,，丹江口水庫消落區(qū)濕地具有較強(qiáng)的氮磷污染削減能力,，植被條件對濕地去氮能力有顯著影響。這也提示在大壩加高后植被重建過程中,，可以通過對消漲帶濕地植被的定向構(gòu)建來增強(qiáng)濕地的去氮功能,，以更好地保障丹江口水庫的水質(zhì)安全,。（生物谷Bioon.com）
生物谷推薦原文出處：
Marine and Freshwater Research DOI:10.1071/MF09013
Phosphorus sorption and desorption characteristics of wetland soils from a subtropical reservoir
Wenzhi Liu , Guihua Liu , Siyue Li , Quanfa Zhang
Abstract
Water-level regulation results in alternating exposure and inundation of soils in reservoir fluctuation zones, which may significantly influence the phosphorus sorption and desorption processes in the soil. The present study investigated the phosphorus sorption and desorption properties of wetland soils in China's Danjiangkou Reservoir using a batch equilibrium technique. Results showed that the maximum phosphorus sorption ranged from 435 to 1429 mg kg-1, with an average of 771 mg kg-1. The maximum phosphorus sorption was found to be significantly related to amorphous iron (r = 0.883, P < 0.01) and pH (r = -0.333, P < 0.05), and the binding constant k was strongly correlated with the amorphous iron (r = 0.475, P < 0.01) and organic matter (r = -0.455, P < 0.01). The phosphorus desorption percentage varied from 8 to 44%, with a mean value of 24%. The present study implies that short-term inundation in reservoir fluctuation zones would result in soil phosphorus desorption to some extent, in spite of the considerable absorption ability in the exposure period. These results are useful for assessing the phosphorus retention capacity of wetland soils and optimising management strategies for water conservation in reservoir regions.
Keywords: Danjiangkou Reservoir, inundation, non-point source pollution, release risk, river regulation.
