水生植物对草型富营养化湖泊气态氮排放及沉积物氮去除的影响  

Effects of macrophytes on gaseous nitrogen emissions and nitrogen removal from sediments in a shallow eutrophic lake

作　　者：邢涛 李俊雄 李彬彬 孙弋祺 李卫平[2] 梁霞[1] 

机构地区：[1]上海大学环境与化学工程学院,上海200444 [2]内蒙古科技大学能源与环境学院,内蒙古包头014010

出　　处：《生态学杂志》2018年第3期771-778,共8页Chinese Journal of Ecology

基　　金：国家重点研发计划(2016YFA0601003);国家自然科学基金项目(41373097;41773076)资助

摘　　要：由人类活动导致的淡水湖泊富营养化以及温室气体排放量增加,已成为当前相关领域的热点问题。本文基于实验室模拟,探讨水生植物光合呼吸作用引起的昼夜溶氧(DO)波动对富营养化草型湖泊沉积物氧化亚氮(N_2O)和氮气(N2)产生及活性氮去除的影响。结果表明,水生植物能够显著增强水体和沉积物表层含氧量的昼夜波动幅度,提高系统DO水平。N_2O和N2排放通量随着DO波动而出现明显的昼夜变化趋势。随着水生植物的种植,参与硝化和反硝化过程的微生物酶活性显著增强,沉积物TN和NH4+-N含量则显著降低。沉积物氮迁移途径分析表明,水生植物吸收固定和N2排放是实验系统脱氮的主要途径。本研究为富营养化湖泊生态修复及温室气体控制管理提供科学依据。Anthropogenic nutrient enrichment in lakes and subsequent increases of greenhouse gas emission are major global problems affecting the ecosystem function of lakes. In this study, laboratory experiments were carried out to investigate the effects of diel dynamics of dissolvedoxygen （DO） cycles, induced by macrophyte photosynthesis and respiration, on nitrous gaseous emissions and nitrogen removal from sediments of a macrophytesdominated eutrophic lake. We found that macrophytes significantly enhanced the diurnal fluctuation of DO in water andincreased sediment oxygen levels. The fluxes of N2O and N2 showed substantial diurnal variation with the fluctuation of DO. Moreover, macrophytes dominated sediments were characterized by significantly higher potential nitrification and denitrification compared to non-vegetated control sediments. The concentrations of TN and NH4＋-N in macrophytes sediments were significantly lower than those in controls. Based on the evaluation of N transformation pathways, we found that nitrogen uptake by macrophytes and N2 emissions were the dominant pathways for N removal from macrophytes dominated sediments. The results provide scientific basis for the ecological restoration of eutrophic lakes.

关 键 词：草型湖泊 富营养化 溶氧 昼夜波动 气态氮 

分 类 号：X173[环境科学与工程—环境科学] X524