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林火是北方针叶林的一种主要干扰方式,不仅影响森林生态系统的生产力和物种多样性,还影响元素的生物地球化学循环。本文选择大兴安岭呼中自然保护区2010年火烧迹地为研究对象,并选择附近未火烧区作为对照样地,分析了火烧(火后1年)对土壤理化性质、土壤微生物生物量和有效养分(N、P、K)的影响。结果表明:与对照区相比,林火显著改变了兴安落叶松林土壤的理化性质,即土壤湿度、有机层厚度、溶解性有机碳、C∶N均显著减小,而土壤pH值则显著上升;同时林火显著减少了土壤微生物生物量,但上述所有土壤性质指标在火烧强度处理间差异不显著。相较于对照样地,轻度火烧和高强度火烧后,土壤有效氮含量均显著增加,但火烧强度间差异不显著;火后土壤有效磷含量也显著高于对照区,且高低强度火烧间存在显著差异;而有效钾变化不显著。
Forest fires are a major disturbance in the coniferous forests of the North, affecting not only the productivity and species diversity of forest ecosystems but also the biogeochemical cycles of the elements. In this paper, we selected the fire burned areas of Huzhong Nature Reserve in Daxing’anling for 2010 as the research object, and selected the nearby un-burned areas as the control plots to analyze the effects of fire (1 year after fire) on soil physical and chemical properties, soil microbial biomass and available nutrients , P, K). The results showed that the forest fire significantly changed the physical and chemical properties of soil in the Larix gmelinii forest, that is, soil moisture, thickness of organic layer, dissolved organic carbon, C: N, and soil pH significantly increased At the same time, the forest fire significantly reduced soil microbial biomass, but all the above mentioned indicators of soil properties were not significantly different between fire intensity treatments. Compared with the control plot, the available nitrogen content of soil increased significantly after mild and high intensity fire, but the difference of fire intensity was not significant. The content of available phosphorus in soil was also significantly higher than that of control area after fire, There are significant differences; while effective potassium changes were not significant.