氮沉降增加对土壤微生物的影响

Effects of nitrogen deposition on soil microorganism

综述了国外氮沉降对土壤微生物的影响研究现状,主要从土壤微生物群落结构组成及功能等方面对氮沉降的响应进行了综述,并从微生物对底物的利用模式及碳分配状况,pH值的变化方面初步探讨了土壤微生物对过量氮沉降的响应机制。研究表明,过量氮沉降会给土壤微生物在以下几个方面带来负影响:首先,改变微生物群落结构组成,表现为土壤真菌细菌相关丰富度发生改变,真菌生物量的减少,真菌/细菌生物量比率的减少,土壤微生物量的减少,微生物群落结构发生改变;其次,改变微生物功能,表现为减少土壤呼吸率,土壤酶活性的降低,改变微生物对底物的利用模式等等。此外,文章还指出了未来该方面研究重点和方向。

As a result of increasing anthropogenic nitrogen deposition, N availability in many forest ecosystems, which are normally N-limited, has been enhanced. Yet, little is known about the effects of nitrogen deposition on microbial activity and community composition. Increased N availability may impact the soil microorganism that are generally regarded as an adaptation to nutrient limited conditions. Based on available scientific knowledge the effects of nitrogen deposition on soil microorganism, including the change of soil microbial community structure and function are reviewed in this paper. The potential impacts were related to the following two aspects. Elevated nitrogen deposition would affect the soil microbial community structure, such as decreased soil microbial biomass, w（C）/w（N）, fungi abundance, fungi/bacteria, and lead to the change of the function of soil microorganism, for example the reduction of soil respiration, extracellular enzymatic activity, and altered the pattern of microbial substrate use. Moreover, the future research work and new method about the nitrogen deposition and soil microorganism is also discussed in this paper.