氮沉降对北方森林土壤氮收支的影响研究进展

Effect of Nitrogen Deposition on Soil Nitrogen Budget in Boreal Forests: Research Progress

氮沉降增加是全球气候变化的重要情景之一,已经对全球氮素循环产生了严重的影响,可能会显著改变生态系统的健康和服务。北方森林,作为地球上仅次于热带森林的第二大生物群区,占全球森林面积的30%,其土壤分系统在调节森林生态系统氮循环和应对全球气候变化中起着重要作用。氮沉降对北方森林土壤氮收支的影响已被广泛关注,并成为全球变化科学领域的热点问题。同时,土壤氮收支作为土壤物质交换和能量转换的主要环节,对氮沉降的响应复杂而多变。因此,为深入了解大气氮沉降对北方森林土壤氮收支的影响,笔者综述了国内外近年来的相关研究成果,分别从土壤氮输入(生物固氮和凋落物分解)、氮固存(微生物固存和外生菌根固存)、氮输出(矿化作用、硝化作用、反硝化作用以及淋溶)以及土壤总氮库的变化趋势等方面分析了土壤氮收支对大气氮沉降的响应,可为科学评估氮沉降对北方森林土壤氮收支的影响提供参考数据。

Increased nitrogen deposition is one of the most important scenarios of global climate change andhas serious impact on the global nitrogen cycle and may significantly alter ecosystem health and services.Boreal forests, as the second largest biome on the earth after tropical forests, accounts for 30% of the globalforest area, and its soil subsystem plays an important role in regulating the nitrogen cycle of forest ecosystemsand coping with global climate change. The effect of nitrogen deposition on soil nitrogen balance in borealforest has been widely concerned and has become a hot issue in the field of global change science. At the sametime, soil nitrogen balance is the main link of soil material exchange and energy conversion, and the responseto nitrogen deposition is complex and changeable. Therefore, to understand the effect of atmospheric nitrogendeposition on soil nitrogen balance in boreal forest, the authors summarized related domestic and foreignresearch results in recent years, from the soil nitrogen input（biological nitrogen fixation and litterdecomposition）, nitrogen storage（microbial solidification and ectomycorrhizal survival）, nitrogen output（mineralization, nitrification, denitrification, and leaching） and the trend of soil total nitrogen pool respectivelyto analyze the response of soil nitrogen balance to atmospheric nitrogen deposition, which could provide reference data for scientifically assessing the effect of nitrogen deposition on soil nitrogen balance in borealforest.