模拟火干扰对森林土壤微生物活性及氮矿化的影响
发布时间：2018-08-25 17:08
【摘要】：火干扰产生热能从而诱导土壤有机质的化学氧化,改变碳和氮转换,对土壤的结构与功能产生严重影响,影响程度取决于火强度、火干扰持续时间和热渗透。在湖南省株洲市高枧林场选取马尾松次生林火烧迹地,按两种土壤、3个温度和3种土壤水势进行试验设计与方差分析,探讨火干扰对土壤微生物及氮矿化的影响。结果表明:无机氮的浓度与火强度和初始土壤有机质含量呈正相关关系;火干扰后短期内土壤碳和氮浓度较高,微生物生物量碳和潜在可矿化氮较低,温度和土壤水势对基础呼吸速率没有显著影响;当土壤温度达160℃时,未受火干扰土壤中潜在可矿化氮浓度迅速不稳定增加,温度达350℃时破坏90%的非微生物组织;土壤加热后水势对氮矿化过程有显著影响,水势越高,潜在可矿化氮损失越大,火干扰土壤的含水量与硝态氮之间呈正相关关系;培养14d期间,土壤火灾历史、热处理和土壤水势对微生物活性、碳和氮矿化有显著影响,-1.5 MPa水势下加热到380℃后两种土壤的微生物生物量碳含量最高,土壤水势和可溶性糖呈负相关关系;水势和火干扰之间的交互作用显著影响微生物活性和氮转换,低水势土壤中的微生物生物量碳、可溶性糖和潜在可矿化氮浓度较高。
[Abstract]:The thermal energy produced by fire can induce the chemical oxidation of soil organic matter and change the conversion of carbon and nitrogen, which has a serious effect on the structure and function of soil. The degree of influence depends on the intensity of fire, the duration of fire disturbance and the heat permeation. In order to study the effect of fire disturbance on soil microorganism and nitrogen mineralization, two soils, three temperatures and three kinds of soil water potential were selected in Gaojian Forest Farm of Zhuzhou City, Hunan Province. The results showed that the concentration of inorganic nitrogen was positively correlated with the intensity of fire and the content of soil organic matter, the concentration of soil carbon and nitrogen was higher and the microbial biomass carbon and potential mineralizable nitrogen were lower in the short term after fire disturbance. When the soil temperature reached 160 鈩，
本文编号：2203550
[Abstract]:The thermal energy produced by fire can induce the chemical oxidation of soil organic matter and change the conversion of carbon and nitrogen, which has a serious effect on the structure and function of soil. The degree of influence depends on the intensity of fire, the duration of fire disturbance and the heat permeation. In order to study the effect of fire disturbance on soil microorganism and nitrogen mineralization, two soils, three temperatures and three kinds of soil water potential were selected in Gaojian Forest Farm of Zhuzhou City, Hunan Province. The results showed that the concentration of inorganic nitrogen was positively correlated with the intensity of fire and the content of soil organic matter, the concentration of soil carbon and nitrogen was higher and the microbial biomass carbon and potential mineralizable nitrogen were lower in the short term after fire disturbance. When the soil temperature reached 160 鈩，
本文编号：2203550
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