城市湿地转变为不同土地利用类型后土壤有机碳垂直分布特征

Vertical Distribution Characteristics of Soil Organic Carbon in Different Land Use Types Changed From Urban Wetland

为阐明人为干扰对城市湿地土壤碳的影响,对由城市湿地转变来的林地、公园绿地、水产养殖地、耕地和防护林带5种土地利用类型不同层次土壤中有机碳（SOC）质量分数进行测定。结果显示：土壤〉0-10cm表层SOC质量分数为林地＞耕地＞防护林带＞公园绿地＞水产养殖地;除公园绿地、水产养殖地之外,表层土壤都表现出SOC富集的特征,并随土层深度增加,质量分数降低;其中生产措施的干扰导致水产养殖地〉50-100cm土壤SOC质量分数出现异常偏高的现象,公园绿地由于一致的高强度绿化管理措施,各土层SOC质量分数并没有表现出显著差异;通过分析5种土地利用类型在各土层SOC质量分数的变异系数,发现表层土壤SOC质量分数空间异质性最高,随土层深度增加,其空间异质性呈逐步降低的趋势。

To clarify the impact of human disturbances on soil carbon in urban wetland,the mass fraction of soil organic carbon（SOC）in different soil layers in five types of land utilization,including woodland,greenbelt,aquaculture land,cultivated land,and shelter forest,were measured.Results revealed that SOC mass fraction in the surface soi〉l0-10 cm was listed in the order of woodland〉cultivated land 〉shelter forest 〉greenbelta〉quaculture land,and SOC in the land types,except for greenbelt and aquaculture land,showed the character of concentration in the discipline of SOC decreasing with the increase of soil depth.The disturbances come from production measures led abnormal rise of the SOC mass fraction in〉50-100 cm soil depth of aquaculture land,however,the SOC mass fraction in all soil layers of greenbelt did not show significant difference because of consistent and intensive virescence action.Coefficient of variation of five land utilization types in different soil depths indicated that the surface soil SOC mass fraction had the highest degree of spatial heterogeneity,and decreasing with the increase of soil depths.