土壤-植物-大气连续体系中氮的研究进展  

Nitrogen in soil-plant-atmosphere continuum:A review.

作　　者：谢腾芳[1,2] 薛立[1] 王相娥[1] 

机构地区：[1]华南农业大学林学院,广州510642 [2]<广东园林>编辑部,广州510055

出　　处：《生态学杂志》2009年第10期2107-2116,共10页Chinese Journal of Ecology

基　　金：广东省林业局资助项目(4400-F07041和4400-F06051)

摘　　要：氮素是植物最需要的重要养分元素之一。近年来,土壤-植物-大气这一连续体系(SPAC)中的氮循环成为研究的热点之一。大气中的氮素可以通过生物固定和N沉降等作用进入土壤和植物内,同时土壤和植物内的氮素又会以氨挥发和氮氧化物等方式排放到大气中。氮素通过生物固持和植物吸收等方式进入植物体内,植物器官脱落使植物损失一部分的氮素,另外雨水的淋洗和植物溢出液也会造成植物的N损失。植物氮素在植物体内的积累和分布随着生长时期和各营养器官而有所不同。另外,植物吸收氮素的过程又受到大气状况和土壤状况的制约。土壤中氮素经过矿化作用、硝化作用和反硝化作用进行转化,一部分把氮素转化成植物能吸收的营养形态,另一部分则从土壤中损失。凋落物的分解和N沉降能补充土壤中的氮素,而植物吸收、微生物固持、水文流失和N溢出等方式使氮素从土壤中损失出去。另外,凋落物的分解和根际土壤、CO2浓度和臭氧对氮素循环有着重要的作用。N污染、N沉降、碳氮循环的耦合作用是今后研究的热点问题。Nitrogen （N） is one of the most important nutrients for plants. Its behavior in soil- plant-atmosphere continuum （SPAC） has become a hotspot in recent years. The atmospheric N can enter into plant and soil via bio-fixation and deposition, and the plant- and soil N can return to atmosphere via ammonia volatilization and nitrogenous gaseous emission. After entered into plant via bio-fixation and plant uptake, part of the N abscises from plant organs, and part of it loses via rainwater leaching and plant secretion. The N accumulation and allocation in plant differ with plant growth stage and plant organ, and the N absorption by plant is limited by the atmospheric and soil status. Through mineralization, nitrification and denitrification, part of soil nitrogen is transformed into the forms that plant can directly use, and part of it loses from soil. Litter decomposition and N deposition can supplement soil N, whereas plant absorption, microbial immobilization, hydrological loss, and nitrogenous secretion can induce the N loss from soil. Litter decomposition, rhizosphere soil, CO2 concentration, and ozone play important roles in nitrogen cycle. In future research, more attentions should be paid on N pollution, N deposition, and the coupling effects of C and N.

关 键 词：大气 植物 土壤 氮循环 

分 类 号：Q948.1[生物学—植物学] S718.5[农业科学—林学]