摘要
通过室内试验模拟胶州湾滨海湿地碱蓬、芦苇、互花米草枯落物的分解过程,测定土壤活性有机碳(可溶性有机碳、微生物生物量碳)含量变化,并利用三维荧光技术对可溶性有机碳(DOC)进行光谱分析.结果表明:土壤活性有机碳含量呈先增加后降低最终趋于稳定的变化趋势;不同枯落物类型和添加方式对土壤活性有机碳的影响不同,表现为碱蓬>互花米草>芦苇,且原状混合>表面覆盖;光谱分析表明,分解过程各三维荧光光谱的荧光峰数量、荧光中心位置和荧光强度都存在一定差异,添加枯落物后土壤未发现类酪氨酸峰;芳香类蛋白物质占比最高,腐殖质类物质次之.枯落物分解是以微生物分解作用为主导、枯落物性质为本质要素、多重因子综合作用的结果,其对提高土壤活性有机碳含量、增强土壤碳库的稳定性具有促进作用;该过程通过改变DOC的结构和化学组分,提高其在土壤中的迁移转化能力,增强生物可降解性和可利用性,促进微生物内源DOC的产生,加快湿地土壤碳循环.
Litter of Suaeda glauca,Phragmites australis,and Spartina alterniflora from coastal wetland of Jiaozhou Bay was decomposed in a laboratory experiment. The contents of soil labile organic carbon including dissolved organic carbon( DOC) and microbial biomass carbon( MBC) were determined,with the spectra characteristics of which being investigated by three-dimensional fluorescence spectroscopy. The results showed that the contents of soil labile organic carbon during litter decomposition increased first,then decreased,and finally tended to be stable. Different litter types and adding ways had different effects on soil labile organic carbon. The contents of soil DOC and MBC decreased in the order of Suaeda glauca,Spartina alterniflora and Phragmites australis. Soil mixed with bulk leaf litter had more soil labile organic carbon than surface mulch. The number and position of fluorescence peak,and fluorescence intensity changed during litter decomposition. No tyrosine-like peaks appeared in the soil with litter addition. Many factors drove litter decomposition,with microbial decomposition being the dominant factor and litter nature as the essential factor. Litter decomposition could improve the content of soil active organic carbon and enhance the stability of soil carbon pool. Litter decomposition changed the structure and chemical composition of soil DOC,which improved its ability of migration and transformation in soil. Moreover,this process enhanced its biodegradability and microbial bioavailability,promoted the production of endogenous DOC by microorganisms,and consequently stimulated carbon cycling of wetland soil.
作者
孙小琳
孔范龙
李悦
狄丽燕
郗敏
SUN Xiao-lin;KONG Fan-long;LI Yue;DI Li-yan;XI Min(College of Environmental Science and Engineering,Qingdao University,Qingdao 266071,Shandong,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2019年第2期563-572,共10页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(41771098)资助~~
关键词
滨海湿地
枯落物
分解过程
土壤活性有机碳
三维荧光特性
coastal wetland
litter
decomposition process
soil labile organic carbon
three dimensional fluorescence spectroscopy characteristics
