城市湿地周边不同土地利用方式下土壤有机碳及其活性组分特征

Soil organic carbon and its active components characteristics under different land utilization types at the periphery of city wetlands

以安徽省蚌埠市龙子湖湿地周边林地、防护林带、水产养殖地、公园绿地、耕地5种土地利用类型为研究对象,探讨不同土地利用方式对土壤有机碳和活性有机碳组分的影响。结果表明,湿地转变为其他土地利用类型后,土壤有机碳呈现显著的土层表聚性,林地较其他土地利用类型有更强的碳截存能力。同种土地利用方式下,土壤易氧化有机碳质量分配比例随土层深度变化产生的变幅范围较小,公园绿地、防护林带和水产养殖地土壤表层颗粒有机碳质量分配比例出现集聚,然而在10 cm以下土层其变化范围较小。土壤有机碳、土壤易氧化有机碳、土壤颗粒有机碳质量分数之间存在极显著(P<0.01)的相关关系,三者在公园绿地与水产养殖地土壤表层质量分数的差异显著性分析结果显示,颗粒有机碳对土地利用方式变化的响应要比土壤有机碳和土壤易氧化有机碳更为敏感。

In order to reveal the action mechanism between land use types and soil organic carbon components,five land utilization types,including woodland,shelter forest,aquaculture land,park green land and cultivated land,were selected as the study objects. It was shown that soil organic carbon（ SOC） aggregated in the surface layer.Compared to the other land use types,woodland exhibited higher carbon sequestration capacity. The quantity distribution proportion of soil easily oxidized carbon（ EOC） exhibited limited variation within the same land use type. The quantity distribution proportion of particulate organic carbon（ POC） in 0- 10 cm soil layer showed aggregation in park green land,shelter forest,and aquaculture land,and the variation of POC below 10 cm soil layer in these three land use types was small. SOC,EOC and POC contents showed significant correlations among each other at 0. 01 level. Compared with SOC and EOC,POC in 0- 10 cm soil layer was more sensitive to changes of land use type in parkgreen land and aquaculture land.