崇明岛深层土壤有机碳空间分布及碳储存特征分析

对上海崇明岛开展5种不同种植类型(粮田、菜田、果园、生态林和湿地)1m深度土壤的碳普查,应用地统计方法分析其深层土壤有机碳含量的空间分布特征,研究不同种植类型对土壤有机碳分布和储存的影响,探明土壤碳循环规律。结果表明,崇明岛深层土壤平均有机碳含量为3.94g·kg~(-1),不同深度土壤有机碳含量在8.73~1.72g·kg~(-1),有机碳储量在2.30~0.47×10~6t,耕层土壤(0-40cm)有机碳储量占总量的65.14%。不同深度土层(0-20、20-40、40-60、60-80和80-100cm)有机碳含量空间分布图表明,各层土壤有机碳含量分布特征大致相同,仅湿地土壤有机碳含量在60cm深度以下相对其它种植类型有所提高。种植类型对深层土壤有机碳分布影响显著,土壤有机碳密度大小表现为菜田粮田果园湿地生态林,土壤有机碳储量则表现为粮田湿地生态林菜田果园。

Spatial Distribution and Storage Feature of Deep Soil Organic Carbon in Chongming Island

In order to further clarify the law of soil carbon cycling in Chongming Island, 1m depth soil organic carbon survey of 5 planting types (cropland, vegetable field, orchard, forest and wetland) was conducted. Based on geostatistics methods, the spatial distribution feature of deep soil organic carbon content in Chongming Island were investigated, and the effects of different planting types on the soil organic carbon distribution and storage were also studied. The results showed that the average deep soil organic carbon content of Chongming Island was 3.94g·kg-1. The range of soil organic carbon content in different depths was 8.73-1.72g·kg-1, and the range of soil organic carbon storage was 2.30-0.47×106 t. The soil organic carbon storage of plough layer (0-40cm) accounted for 65.14% of the total amount. The maps of soil organic carbon content distribution of different depths (0-20, 20-40, 40-60, 60-80 and 80-100cm) were drawn. The feature of organic carbon content distribution in different soil depths were similar with each other, except that under the depth of 60cm, soil organic carbon content in the wetland was higher than the other planting types. There were significant effects of different planting types on the soil organic carbon distribution. The sequence of soil organic carbon density was vegetable field>cropland>orchard>forest>wetland, and the sequence of soil organic carbon storage was cropland> wetland>forest>vegetable field>orchard.