火干扰对塔河白桦落叶松林土壤化学性质的短期影响

Short-term influence of fire on soil chemical properties in forest mixed by birch and larch

火一直是我国北方森林的重要干扰因子,在气候变化影响下,其干扰作用进一步增强。该文对大兴安岭地区代表性森林白桦落叶松林不同强度火烧迹地经过1个生长季后土壤化学性质进行了调查分析。结果表明:不同火强度干扰后的土壤化学性质常呈现显著性差异,火强度对扰动程度具有重要影响,是决定扰动程度的关键因子。火干扰提高了土壤的p H值,促进了养分回归,提高了土壤养分含量。白桦落叶松林地土壤p H值随火干扰强度的增加而升高;土壤全氮、全磷、全钾平均含量中强度火干扰林地>高强度火干扰林地>低强度火干扰林地>无火对照样地;土壤铵态氮含量随林火强度的增强而减少,但火干扰提高了土壤硝态氮含量,强度越高硝态氮含量增加的越多;白桦落叶松林土壤有效磷平均含量中强度火干扰林地>低强度火干扰林地>高强度火干扰林地>无火对照样地,土壤速效钾平均含量中强度火干扰林地>高强度火干扰林地>低强度火干扰林地>无火对照样地。

Fire was an important disturbance factor of forest in the north of China.Under the influence of climate change,the interference effect of fire was further strengthened.In this study,chemical properties of soil in Forest mixed by Betula platyphylla and Larix gmelinii（which was a typical forest in Daxinganling） were investigated and analyzed after a growing season since the forest had undergone different intensity of burning.The results showed that the soil chemical properties after different intensity burnings were significantly different and the fire intensity was the key factor to determine the degree of disturbance.Fire disturbance increased the p H valueof soil,promoted the nutrient return,and increased the content of soil nutrient.Soil p H value increased with the increase of fire intensity;the rank of average contents of total N,total P,total K in soil was as following：moderate strength fire disturbance woodland 〉 high strength fire disturbance woodland 〉 low fire disturbance woodland 〉 no fire plots; ammonium nitrogen content reduced with en- hancing fire intensity, but burning enhanced nilrate nilrogen content in soil, the higher the fire intensity the bigger the content; the con- tent of available P in moderate intensity fire land 〉 low intensity land 〉 high intensity land 〉 no fire land; average content of available K in soil of mean slrength woodland 〉 high fire disturbance woodland 〉low fire disturbance woodland 〉 no fire woodland.