摘要
通过对大兴安岭地区新林林业局 2 0a内不同年份间隔的 11块火烧迹地土壤进行调查取样和室内实验分析 ,发现火烧后不同年限、不同强度的火烧迹地 ,土壤全氮与有效氮含量变化情况如下 :低强度火烧后 9d ,土壤全氮和有效氮含量均比未烧前低 ,这与中、高强度火烧后的情况正好相反。火烧后 4a内 ,土壤氮的含量基本都比未烧林地有所下降 (中强度火烧迹地土壤有效氮含量除外 )。以后有逐年增加的趋势。火烧迹地降第一场雨后 ,低强度火烧迹地土壤全氮比降雨前减少 ,有效氮增加 ;中强度火烧迹地土壤全氮和有效氮均比降雨前增加 ;高强度火烧迹地土壤全氮和有效氮均比降雨前有所下降。连年火烧迹地土壤全氮减少 。
Soil sampling and investigation were conducted in 11 burned sites with different interval periods of fire years within 20 years in Xinlin Forest Bureau of Daxing'anling Region. Laboratory analysis indicated that the contents of full nitrogen and active nitrogen are different in these burned sites with different fire intensities and fire years. The contents of full nitrogen and active nitrogen of soil after 9 years of light burn are lower than that before burn, which is contrary to the situation of moderate burn and severer burn. Within 4 years after fire, compared with unburned site, the content of nitrogen in soil showed a light decline, except the active nitrogen of soil in moderate burned sites, and had an increasing trend year by year after 4 years. After first rainfall, on light burned site the full nitrogen content of soil decreased but the active N content increased, while both full nitrogen and active nitrogen increased on moderate burned site but decreased on severer burned site, compared with that before the rainfall. On site with frequent fire the content of full nitrogen of soil decreased but the content of active nitrogen increased.
出处
《防护林科技》
2002年第4期1-4,28,共5页
Protection Forest Science and Technology
关键词
林火
土壤
氮
含量
扰动作用
强度
Forest fire intensity
Burned years
Full nitrogen
Active nitrogen
Soil
