【摘要】 采用模拟方法研究了天然阔叶红松林和天然次生杨桦林中土壤微生物碳、氮对大气氮沉降升高的响应。林地控制施氮量分别为:对照(0)、低氮(25 kg.(hm2.a)-1)和高氮(50 kg.(hm2.a)-1)。施氮后的第一个生长季,生长初期(5月)、生长旺季(7月)和生长末期(9月)的观测研究表明:氮沉降增加对微生物C、N的影响因森林类型和时间不同而存在显著差异。由此表明,1 a的施氮试验并没有使土壤氮达到饱和状态,但是短期的施氮可以在某些月份内显著影响土壤微生物C、N及其微生物m(C)∶m(N)。更多还原

【Abstract】 An experiment was conducted to study the effects of simulated nitrogen deposition on soil microbial biomass C and N in natural broadleaf-Korean pine(Pinus koraiensis) mixed forest and natural secondary poplar(Populus alba) and birch(Betula platyphylla) mixed forest.The experiment included low N deposition level(25kg·hm-2·a-1),high N deposition level(50kg·hm-2·a-1) and the control without N addition.The soil microbial biomass C and N were observed in May,July and September during the first growing season after nitrogen addition.Result showed that the responses of microbial biomass C and N to elevated N deposition varied with forest type and growing period.It indicated that N deposition did not cause soil nitrogen to reach saturation point after a one-year experiment,but short-term nitrogen addition could significantly affect the microbial biomass C and N as well as C/N ratio in certain growing periods in these two forests.更多还原