氮磷沉降对森林土壤生化特性影响研究进展

Research Progress in the Effect of Nitrogen and Phosphorus Deposition on Biochemical Characteristics of Forest Soil

人类活动引起的氮磷沉降给土壤带来严重影响。外源性氮可以直接增加土壤全氮和碱解氮的含量,提高土壤磷的有效性,减少全磷含量;外源性磷可以促进树木对土壤氮的吸收,可能造成土壤全氮含量下降。外源性氮对微生物群落存在促进、抑制和没有影响3种情况。外源性磷通常可增加微生物生物量,改变原有的森林微生物群落组成;氮沉降可以提高、降低或无影响土壤酶的活性。氮磷沉降对不同土壤酶种类的影响效果各异。氮沉降的影响也与土壤深度及酶的种类有关。对磷沉降影响土壤酶的研究甚少。未来氮磷沉降的研究热点包括热带氮磷沉降、土壤氮磷比和氮磷沉降交互作用对土壤的影响,不同地形、森林类型、林龄条件下氮磷沉降的对比分析,生态系统中缓冲氮磷沉降作用的关键因子及全球气候变化下氮磷沉降对土壤的影响。

Nitrogen （N） and phosphorus （P） deposition caused by human activities imposes a serious impact on soils. Exogenous N can directly increase the contents of total N and available N in soils, improve soil P availability, and reduce the total P content ; exogenous P will increase N absorption of trees from soils and may decrease soil total N. The effect of exogenous N on the microbial community exists in three cases： promotion, inhibition and no effect. Exogenous P usually increases microbial biomass, changes the original microbial community composition of forests; exogenous N can increase, decrease or have no effect on the activity of soil enzyme. Effects of N and P deposition on soil enzymes vary. Effect of exogenous N on soil enzyme activity is related with soil depth and enzyme species in forest soil. Little study has been conducted on the effect of exogenous P on enzyme. Future study on N and P deposition will focus on tropical N and P deposition, ratio of N to P of soil, interaction effect of N and P deposition on soils, comparative analysis of N and P deposition under different terrains, forest types, forest ages, the key factor to buffering N and P deposition in ecosystem, the effects of N and P deposition on soil under the global climate change.