氮沉降对土壤动物影响的研究进展

The impact of nitrogen deposition on soil animals:A review

土壤动物是生态系统的分解者,在维持物质循环和能量流动方面起着重要作用,人类引起的氮沉降对土壤动物的组成和结构产生了巨大影响。通过研究发现,在自然生态系统,模拟氮沉降会降低土壤动物的多度和多样性,但是在人工(如农业)生态系统中氮素添加会增加土壤动物的多度和降低其多样性。氮素添加对人工生态系统中线虫多度的促进效应存在阈值效应。氮沉降对土壤动物组成和结构的影响主要通过2种:1)氮素添加后土壤铵离子浓度增加,其对土壤线虫产生直接的抑制效应;氮素添加导致土壤酸化进而影响土壤线虫的多度和多样性;2)氮素添加通过改变其它生物(如植物、微生物)群落而间接的影响土壤动物。

As the decomposer of soil ecosystem,soil animals play important roles in nutrient mineralization and other ecological processors of soil ecosystem.Human-induced nitrogen deposition threaten the structure and composition of soil animals.Researchers have investigated the responses of soil animals to nitrogen addition from grassland to agricultural ecosystems.Here,we review literature from the past decades and find the following patterns：in natural ecological system,simulated nitrogen deposition reduces the abundance and diversity of soil animals,but in the artificial ecosystems,such as in agricultural ecosystem,nitrogen addition increases the abundance of soil animals with a dose threshold effect,also decreases the diversity of soil animals.Primarily two possible mechanisms of nitrogen effects on soil animals have been proposed：nitrogen addition either directly inhibits soilnematodes bydeteriorated soil physicochemicalenvironment（e.g.,acidification and accumulatedsoil ammonium ions）,or indirectly influences soil animals through altering plant community and microorganism.