【摘要】 以福建漳江口、九龙江口、闽江口和浙江乐清湾为研究区,采集红树林和入侵种互花米草(入侵前为红树林)湿地土壤样品,分析互花米草入侵后土壤有机碳(SOC)、有机碳储量(SOCS)、活性有机碳组分(微生物生物量碳MBC、易氧化有机碳EOC、水溶性有机碳WSOC)以及有机碳键合组分(钙键结合有机碳(Ca—SOC)和铁铝键结合有机碳(Fe(Al)—SOC))的变化,探讨互花米草入侵对土壤有机碳组分以及稳定性的影响。结果表明:互花米草入侵红树林后,土壤SOC、SOCS、MBC和EOC总体上有所降低,尤其是SOC和SOCS,其降低的比例分别约为9.86%~27.13%和13.95%~26.29%;土壤WSOC含量则增加,增加比例约为5.75%~53.52%;互花米草入侵对土壤有机碳键合组分也具一定的影响,其中Ca—SOC/SOC比值增加,而[Fe(Al)—SOC+残渣态SOC]/SOC比值降低。这些结果预示着互花米草入侵改变了土壤有机碳库,同时也一定程度削弱了土壤有机碳稳定性。土壤有机碳的化学键合可能是红树林湿地土壤有机碳稳定的主要保护机制,对红树林碳汇功能具有重要意义。更多还原

【Abstract】 To investigate the effect of Spartina alterniflorainvasion on soil organic carbon fractions and the stability of soil,the soil samples were collected from wetlands of mangroves and invasive species S.alterniflora(before invasion was mangrove forest)in the Zhangjiangkou Estuary,Jiulong River Estuary and Min River Estuary of Fujian,and Yueqing Bay of Zhejiang.The contents of soil organic carbon(SOC),soil organic carbon storage(SOCS),active organic carbon fractions(microbial biomass carbon-MBC,easily oxidized organic carbon-EOC and water soluble organic carbon-WSOC)and chemical bonded organic carbon components(calcium bonded organic carbon(Ca—SOC)and iron-aluminum bonded organic carbon(Fe(Al)—SOC))were measured in laboratory.These results showed that compared with the mangrove,soil SOC,SOCS,MBC and EOC contents decreased after S.alterniflorainvasion,especially SOC and SOCS,their reduction rates were about 9.86%~27.13% and 13.95%~26.29%,respectively.While,soil WSOC content had increased by5.75%~53.52%.Soil chemical bonded organic carbon components were also influenced by S.alterniflora invasion.The ratio of Ca—SOC/SOC increased,while the ratio of[Fe(Al)—SOC+residual state SOC]/SOC decreased.These results indicated that S.alterniflora invasion not only changed the soil organic carbon pool,but also changed its stability.The chemical bond of soil organic carbon might be the main protective mechanism for the soil organic carbon stability in mangrove wetland,which was important for mangrove carbon sink function.更多还原