中文摘要：

土壤硝化和反硝化作用是生态系统中氮循环的两个重要环节，是氮素损失的潜在途径，土壤硝化和反硝化作用可向大气中释放温室气体，由此带来环境危害。本文综述了国内外学者对土壤硝化和反硝化作用的研究现状，总结了土壤硝化和反硝化作用的研究方法及其影响因子。土壤硝化和反硝化作用是两个非常复杂的生态学过程，针对研究工作中存在的不足，提出建议：1）改进实验方法、加强对总硝化作用的研究；2）进一步探索森林生态系统中硝化和反硝化作用规律；3）注重对土壤中硝化和反硝化作用微生物学机理的研究。

英文摘要：

Nitrification is the biological conversion of organic or inorganic nitrogen compounds from a reduced to a more oxidized state. Denitrification is generally referred to as the microbial reduction of nitrate to nitrite and further gaseous forms of nitric oxide, nitrous oxide and molecular nitrogen. They are functionally interconnected processes in soil nitrogen cycle that are involved in the control of longterm nitrogen losses in ecosystems through nitrate leaching and gaseous N losses. The advances in studies of soil nitrification and denitrification and controlling factors are reviewed in this paper.