氮沉降及物种多样性影响草地氧化亚氮排放研究进展

Research progress on effects of nitrogen deposition and species diversity on nitrous oxide emission from grassland

氮沉降以及由此引起的植物群落组成变化,直接或间接影响了生态系统对全球气候变化的反馈效应.氧化亚氮排放作为全球气候变化的重要驱动因子之一,对氮沉降等因子有明显响应.土壤中氧化亚氮的生成实质上是硝化类和反硝化类微生物吸收利用土壤中无机和有机态氮时的代谢产物,植物群落中各物种与土壤的硝化和反硝化作用之间的相互作用极为复杂,涉及植物对不同形态无机氮素的选择性吸收、植物生长残留的有机氮等诸多因素.追踪氮沉降和草地植物群落组成对氧化亚氮排放作用机制不仅能为更好的理解天然草地生态系统对氮沉降的反馈提供理论依据,而且能够为农业生态系统中,借鉴多样性原理减少氮素损失提供新思路.

Increased concentrations of N in the atmosphere through deposition alter plant community composition.This variation results in the feedback effect of ecosystem on global climate change,with directly or indirectly effects.Nitrous oxide(N_(2)O)acts as the most important greenhouse gas driving global climate change and has significant impacts on the collaborative variation between nitrogen deposition and plant community composition.The formation of N_(2)O in soil is essentially the metabolite of nitrifying and denitrifying microorganisms when absorbing and utilizing inorganic and organic nitrogen in soil.The interaction between species in plant community and soil nitrification and denitrification is extremely complex,involving many factors such as selective absorption of different forms of inorganic nitrogen by plants,residual organic nitrogen in plant growth and so on.Tracing the mechanism of nitrogen deposition and grassland plant community composition on N_(2)O emission can not only supply a theoretical basis for better understanding the feedback of natural grassland ecosystem to nitrogen deposition,but also provide a new idea for agricultural ecosystem to learn from the principle of diversity to reduce N_(2)O loss of nitrogen.