【摘要】：以河北平泉油松林近期(火后半年)火燒跡地為研究對(duì)象,根據(jù)樹(shù)干熏黑高度和樹(shù)木死亡率情況,劃分不同火燒強(qiáng)度(輕度、中度、重度),并以鄰近未火燒區(qū)設(shè)置對(duì)照樣地,采用氯仿熏蒸浸提法測(cè)定各研究區(qū)土壤微生物量碳、氮(C_(mic)、N_(mic)),分析不同強(qiáng)度火燒對(duì)其土壤微生物量碳、氮(C_(mic)、N_(mic))的影響。結(jié)果表明:不同強(qiáng)度火燒后土壤C_(mic)、N_(mic)含量均呈下降的趨勢(shì),不同土層間土壤C_(mic)、N_(mic)含量隨土層深度增加而逐漸減小,土壤C_(mic)變化在34~205 mg/kg之間,土壤N_(mic)變化在7~40 mg/kg之間;土壤微生物量碳氮比(C_(mic)/N_(mic))整體處于5~6之間。雙因素方差分析表明:火燒強(qiáng)度、土層深度及二者的交互作用對(duì)土壤有機(jī)碳(SOC)、全氮(TN)、銨態(tài)氮(NH+4-N)、硝態(tài)氮(NO-3-N)均有顯著影響(P0.05),對(duì)于土壤p H值,僅火燒強(qiáng)度對(duì)其影響顯著(P0.05);同時(shí),火燒強(qiáng)度、土層深度及二者的交互作用對(duì)土壤C_(mic)和N_(mic)的影響均達(dá)到極顯著水平(P0.01)。土壤養(yǎng)分(SOC、TN、NH+4-N和NO-3-N)主要集中在表層(0~10 cm),重度火燒后土壤養(yǎng)分含量顯著減少,同時(shí),土壤p H顯著升高。相關(guān)分析結(jié)果表明:土壤有機(jī)碳、全氮對(duì)土壤C_(mic)、N_(mic)有極顯著影響(P0.01),土壤C_(mic)、N_(mic)含量與土壤有機(jī)碳、全氮均呈正相關(guān)。主成分分析進(jìn)一步表明土壤有機(jī)碳、全氮是影響土壤C_(mic)、N_(mic)的主要因素。
[Abstract]:Taking the burning site of Pinus tabulaeformis forest in Pingquan, Hebei Province (half a year after the fire) as the research object, according to the blackening height of trunk and the mortality of trees, different burning intensities (mild, moderate, severe) were divided into different burning intensities (mild, moderate, severe). The soil microbial biomass carbon and nitrogen (C _ (mic), N _ (mic),) were determined by chloroform fumigation extraction in the adjacent unburned areas. The effects of different intensities of burning on soil microbial biomass carbon and nitrogen (C _ (mic), N _ (mic) were analyzed. The results showed that the content of soil C _ (mic), N _ (mic) decreased with the increase of soil depth, the content of soil C _ (mic), N _ (mic) decreased with the increase of soil depth, the change of soil C _ (mic) was between 34 鈮，

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