Environmental effect of sediment dredging in lake:IV influences of dredging on microbial activity and functional diversity of microbial community in sediments and its significance

通过为期-年的疏浚模拟试验,在试验室培养疏浚与对照柱样研究了底泥疏浚对沉积物微生物活性和群落功能多样性的影响。研究结果表明,太湖梅梁湾研究区模拟疏浚表层30cm对沉积物物理、化学和微生物性质影响较大。疏浚沉积物微生物活性显著低于未疏浚沉积物的微生物活性,疏浚对沉积物微生物活性影响较大且在-年的试验周期内难以恢复。底泥疏浚对沉积物微生物功能多样性产生影响,疏浚后初期新生表层沉积物的微生物群落多样性指数显著低于未疏浚沉积物,底泥疏浚改变了沉积物中微生物群落组成,并会导致微生物群落功能多样性降低。底泥疏浚对微生物活性与微生物群落功能多样性产生影响,从而对沉积物中生源要素的循环产生影响。;A laboratory experiment for studying the effects of sediment dredging on microbial activity and functional diversity of mi-crobial community of sediments was carried out through one year. Using incubation of undredged(control) and dredged cores, wefound that dredging the upper 30cm layer of sediment remarkably affected physico-chemical and microbial characteristics of sedi-menu in the study area of Meiliang Bay, Lake Taihu. The microbial activity in dredged sediments was significantly lower(P<0.05)than that in undredged sediments. Sediment dredging affected considerably microbial activity in sediments, and the microbi-al activity in dredged sediments could not recovery in one year experiment. Sediment dredging also affected the functional diversityof microbial community in sediment, the diversity index of microbial community in early dredged sediments was significantly lower(P<0.05) than that in undredged sediments. Sediment dredging modified the community composition of sediment microbial eco-system and resulted in decreasing of diversity of microbial community. Sediment dredging affected microbial activity and functionaldiversity of microbial community, which consequently affected the cycling of biogenic elements in sediments.