中文摘要：

应用空间代替时间的方法对大兴安岭林区白桦落叶松混交林1982—2007年的中度火烧迹地土壤理化性质变化进行研究。结果表明：火后土壤密度增加,土壤孔隙度和土壤含水率降低,但是变化幅度将随着时间的推移逐渐缩小,并在火烧后第20年将接近火烧前水平;火烧后A层和B层土壤有机质均呈降低趋势,A层的降幅逐渐缩小直到火烧后20年比火烧前水平大幅增加;火后土壤A层和B层全磷含量均呈增加趋势,土壤全氮在A层基本也呈增加趋势,B层随火后时间呈波动变化,无明显规律;土壤有效磷含量变化呈先降低后增加的趋势;A层土壤速效钾含量的变化基本呈增加趋势,但随时间增加幅度减小,而B层的变化无规律;A层土壤水解氮含量变化呈增加趋势,而B层的变化则与速效钾在B层的变化相似,无明显规律。此研究旨在找出火烧后随时间的推移土壤理化性质的动态变化规律,为火烧迹地的改造和生态恢复提供科学依据。

英文摘要：

By using the space substitution of time method,the forest soil physical and chemical properties in the burned areas,which burned from 1982 to 2007,were investigated.The unburned nearby areas served as the control.This study was conducted in Betula platyphylla-Larix gmelinii mixed forests in Daxing＇anling area.The results showed that：soil bulk density increased after being burned,soil porosity and soil water content reduced after being burned.But the variation gradually reduced with time,and the parameters eventually returned to close to the level of the unburned in 20 years;Soil organic matter in A and B layer in the burned area had a descending trend,and the decrease rate in A layer gradually slowed down with time until the 20th year by which the soil organic matter was more than the level of the unburned.Soil total phosphorous content in A and B layer in the burned area basically showed an increasing trend,and soil total nitrogen in A layer had the same variation trend,while the nitrogen in B layer fluctuated over the years after being burned,without any apparent regulation.Soil effective phosphorous basically showed an increasing trend,but the change rate in A layer with time gradually reduced,and that in B layer had no obvious regulation.Soil hydrolysis nitrogen content in A layer increased,but its variation in B layer had no regulation.Soil available potassium did not show any regulation.The purpose of this study is to find out the change pattern of the soil physical and chemical properties with time after being burned.This study would provide a scientific basis on ecological restoration and land reclamation in burned areas.