长江口九段沙湿地土壤有机碳及微生物陆向分布

Landward Distribution of Soil Organic Carbon and Soil of Jiuduansha Wetland of Yangtze River Estuary

通过分析九段沙湿地土壤有机碳及微生物因子的陆向分布,研究了土壤有机碳的空间差异性及其与土壤微生物因子的相互关系。结果表明,九段沙土壤有机碳的陆向分布具有显著差异(P<0.05),随着高程上升,其含量整体呈现增大趋势,互花米草区/芦苇混合区最高(9.18g·kg-1);土壤微生物因子的陆向分布与土壤有机碳相似,且与土壤有机碳含量呈显著正相关关系(P<0.01),其中以土壤微生物呼吸和土壤脱氢酶最为明显;互花米草的引种及蔓延,增加了区域土壤有机碳含量,也增强了土壤微生物活性。

To clarify the landward distribution of soil organic carbon（SOC ） and soil microbial factors at Jiuduansha Wetland, located at the Yangtze Estuary, the spatial difference of SOC and soil microbial factors, as well as their relationship were studied by analyzing organic carbon, microbial biomass, enzyme activity and microbial respiration of soil samples in different elevation gradients collected in July, October, December 2008 and March 2009, respectively. The experimental results will provide some useful references for illustrating capacity of carbon accumulation of Jiuduansha wetland. The results indicate that along with ascent of elevation gradient, SOC varies significantly （P〈0.05）, generally is increase, and that of the district mixed with Spartina alterniflora/Phragmites australis is the highest（9.18 g·kg^-1） among the five elevation gradient types. The landward distribution of soil microbial activity is similar to that of SOC. What is more, it is positively correlated with the content of SOC （P〈0.01 ） and soil microbe respiration and soil dehydrogenase are the main factors related with SOC. Sp artina alte rniflora can increase the concentration of SOC as well as the soil microbial activities.