小兴安岭森林沼泽湿地土地利用变化对土壤活性碳组分的影响

目的]以小兴安岭森林沼泽为研究对象,研究湿地经过人类活动开垦为农田,和排水造林,以及弃耕地的土壤活性碳组分,为深入了解土壤活性碳组分动态变化及其可能影响全球变暖的机制研究提供科学依据。方法]选择小兴安岭森林沼泽湿地4种土地利用方式(天然沼泽、排水湿地、弃耕地、农田)为研究对象,在野外调查和室内分析的基础上,对比分析土壤有机碳(SOC)、溶解性有机碳(DOC)、微生物碳(MBC)、易氧化碳(EOC)、轻组有机碳(LFOC)、颗粒有机碳(POC)的含量变化和比例关系,并用相关分析法分析土壤有机碳各活性组分之间的关系。结果]不同土地利用方式土壤有机碳含量随土层深度增加而降低,总体上,在土壤剖面上,天然沼泽的SOC含量大于其他土地利用方式,其他3种土地利用方式之间差异不显著(p0.05)。不同土地利用方式下土壤活性碳组分(DOC,MBC,EOC,POC,LFOC)含量在垂直分布上均呈现出随土壤深度的增加而降低的趋势,土壤活性碳组分含量顺序总体上呈:天然沼泽排水湿地弃耕地农田。4种土地利用类型土壤DOC占SOC的比例,在垂直剖面上,无明显规律变化。土壤SOC含量与DOC,MBC,EOC,POC,LFOC之间的相关性均达到显著水平(p0.05)。土壤DOC和MBC之间呈显著性正相关(p0.05),LFOC和POC之间呈极显著性正相关(p0.05),EOC与其他活性碳组分相关性均不显著(p0.05)。结论]土地利用变化会对小兴安岭森林沼泽土壤活性碳组分产生影响,应该合理开发小兴安岭森林沼泽湿地。

Effects on Component of Activated Carbon in Soil Under Different Patterns of Land Use in Lesser Khingan Mountains

Objective] This thesis took the marsh in Lesser Khingan Mountains as the object, to research the component of activated carbon in soil after wetland was transformed to farmland, forests. This abandoned farmland, which is of great scientific significance to the further understanding on the dynamic change of activiated carbon in soil and the corresponding effects of global warming mechanism.Methods] This research selected four different types of land use(natural marsh, drainaged wetlands, abandoned farmland, farmland) as the objects, based on field investigation and indoor analysis, making a comparison of the content changes and proportion relations among soil organic carbon(SOC), dissolved organic carbon(DOC), microbial biomass carbon(MBC), easily oxidized organic carbon(EOC), light fraction organic carbon(LFOC), particulate organic carbon(POC). This research made an analysis of the relationship between active componets of organic carbon in soil with the correlation analysis.Results] The content of organic carbon decreases with the increasing depth of soil under different land use patterns. In general, on the soil profile, the content of SOC in natural marsh is greater than that in other land use patterns, while the difference among the other three patterns of land use is not significant(p > 0.05). Under the four different land use patterns, the content of activated carbon component all shows a decrease tendency with increasing of soil depth in the vertical distribution. Generally, the contents of activated carbon component in the four different types of land use patterns are natural marsh > drainage wetlands > abandoned farmland > farmland.The correlation between SOC and DOC, MBC, EOC, POC, LFOC in soil is significant(p < 0.05).There is a significant positive correlation between DOC and MBC in soil(p < 0.05).There is rather a significant positive correlation between LFOC and POC in soil(p < 0.05).The correlation between EOC and other activated carbon components is not significant.Conclusion] There are effects on the component of activated carbon in soil under different patterns of land use in Lesser Khingan Mountains. Therefore, people should rationally develop the marsh in Lesser Khingan Mountains.