人为干扰对小兴安岭森林湿地土壤碳组分和酶活性的影响

以小兴安岭落叶林沼泽湿地为研究对象,对比研究皆伐地、火烧地和落叶松湿地土壤碳组分和酶活性.结果表明:(1)3种湿地类型土壤SOC含量表现为对照地显著高于皆伐地和火烧地(p0.05),在0~10 cm土层中皆伐地与对照地相比降低了58.38%,火烧地与对照地相比降低了61.96%.皆伐地与火烧地在不同土层的土壤中SOC含量差异不显著(p0.05);DOC含量对照地显著高于皆伐地和火烧地(p0.05).在0~10cm土层中火烧地DOC含量是皆伐地的1.99倍,两者差异不显著(p0.05);不同干扰方式对土壤MBC含量影响的差异主要表现在0~10 cm的土层土壤,对照地分别比皆伐地和火烧地高23.13%和95.79%(p0.05).在不同的土层中皆伐地MBC含量均大于火烧地,与SOC含量的变化趋势一致.(2)与对照地相比,皆伐地与火烧地0~10 cm土层的土壤蔗糖酶活性分别降低了45.59%和36.76%,脲酶活性显著降低了18.22%和55.69%(p0.05),蛋白酶活性降低了19.65%和17.34%,淀粉酶活性降低了6.29%和10.69%.土壤碳组分和酶活性在垂直方向上均表现为随着土层深度增加而减小.皆伐和火烧造成森林湿地土壤碳组分和酶活性降低.

Effects of human disturbance on soil carbon fractions and enzyme activities in forest wetlands of Xiaoxing'an Mountains

In this paper, the marsh wetland of deciduous forest in Xiaoxing''an Mountains was taken as the research object to study carbon fractions and enzyme activities in clear-cutting land, burned area and larch wetland. The results show that:SOC content of the three types of wetland was as follows:SOC in the control area was significantly higher than that of the clear-cutting land and the burning area (p<0.05). Compared with the control area, in the 0~10 cm soil layer, the clear-cutting land decreased by 58.38%, and the burned area decreased by 61.96%. The content of SOC in soil of different soil layers was not significantly different (p>0.05). The content of DOC was significantly higher than that of clear-cutting land and burning area (p<0.05). In the 0~10 cm soil layer, the content of DOC in the burning area was 1.99 times higher than that in the clear-cutting land, but there is no significant difference (p>0.05). The difference of soil MBC content in different disturbance ways was mainly in soil layer of 0~10 cm, and MBC in control was 23.13% and 95.79% (p<0.05) higher than those in clear-cutting land and burned area respectively. In different soil layers, the content of MBC in clear cut soil was higher than that in burned area, and the trend of SOC content was identical with that in the field. Compared with the control, both soil sucrase activity and soil 0~10cm of fire were reduced by 45.59% and 36.76%, the urease activity decreased significantly by 18.22% and 55.69% (p<0.05), the protease activity decreased by 19.65% and 17.34%, the amylase activity decreased by 6.29% and 10.69%. The soil carbon fractions and enzyme activities decreased in vertical direction with the increase of soil depth. These results indicated that the clear-cutting and burning resulted in lower soil carbon fractions and enzyme activities in forest wetlands.