作　　者： ; ; ; ; ; ; ; ;

机构地区： 同济大学环境科学与工程学院污染控制与资源化研究国家重点实验室

出　　处： 《生态学报》 2010年第18期5022-5032,共11页

摘　　要： 为阐明促淤和堤内农业生产对长江口滩涂湿地土壤微生物呼吸(SMR)的影响,在崇明东滩和九段沙湿地设置3个典型区域,研究了人为扰动和自然状况下湿地SMR的差异性,并通过分析不同类型湿地土壤的微生物活性和环境因子阐明了导致SMR差异的主要原因。结果显示,促淤区现有湿地SMR强度((0.41±0.22)mgCO·2g-·124h-1)高于自然状态区((0.07±0.02)mgCO·2g-·124h-1),且差异达到了极显著水平(P<0.01);堤内不同农业生产模式导致的施肥强度差异对堤外湿地SMR也有一定影响。通径分析表明,促淤等人为扰动状态下湿地土壤微生物活性增强是导致其SMR较高的主要原因,其中土壤原核微生物多样性指数及蔗糖酶活性与SMR强度的关联性尤为显著。而促淤与堤内化肥施用所引起的已有滩涂湿地土壤环境条件的改变,特别是土壤含水量下降和无机氮含量增高是导致其微生物活性发生改变的重要原因。总体而言,促淤和堤内高强度施肥的农业生产模式一定程度上会增强堤外现有滩涂湿地的SMR,从而弱化其碳汇功能。 The effect of siltation promotion and the agricultural utilization mode of the inning land on soil microbial respiration （SMR） in tidal wetlands of the Yangtze River estuary were investigated.Three typical zones in Chongming Dongtan and Jiuduansha,located near the Yangtze River estuary,were studied to determine the variability of SMR in natural and artificially disturbed wetland areas.The causes of the differences in SMR were also studied by analyzing microbial activity and physical-chemical characteristics of the different wetland soils.Results showed that the SMR of the existing wetland in the siltation promotion zone was significantly higher （P0.01） than that of the natural zone.Different agricultural practices on the inning land also affected the SMR of the tidal wetlands.Higher soil microbial activity in the artificially disturbed tidal wetland may be the main cause of its high SMR.Path analysis indicated that the correlation between soil prokaryotic microorganism diversity,invertase activity and SMR were especially prominent.Siltation promotion and agricultural utilization of the inning land leading to a change in soil structure and characteristics of the existing tidal wetland,such as decrease of water capacity and increase of inorganic N,may be important reasons for the differences in soil microbial activities between the artificially disturbed and the natural tidal wetland.All of the results indicated that siltation promotion and agricultural production on the inning land would enhance SMR of the existing wetland,thus decreasing its carbon accumulation capability.The investigation provided useful guidance for wetland protection schemes and the better utilization of tidal areas in the Yangtze River estuary.

关 键 词： 崇明东滩 九段沙 通径分析 微生物活性

领　　域： [农业科学] [农业科学]