作　　者： ; ; ;

机构地区： 中国科学院地理科学与资源研究所资源与环境信息系统国家重点实验室

出　　处： 《土壤学报》 2003年第1期118-122,共5页

摘　　要： 测定了中国中东部地区 1 7种土类 45个样点近表层 1 0cm土样中水溶性有机物的紫外光谱和分子量分布特征 ,同时测定部分样品富里酸的相应特征。在此基础上比较和分析水溶性有机物与富里酸紫外光谱特征的差异、紫外光谱特征与样品平均分子量分布的关系及其地域分异规律。结果表明土壤水溶性有机物和富啡酸具有相似的紫外光谱特征 ;WSOC样品紫外 /可见光比值与其平均分子量负相关 ,而WSOC单位浓度的紫外吸收值则与平均分子量正相关。研究区水溶性有机物的单位浓度紫外吸收值具有明显的自北向南和自东向西递降的趋势 ,从根本上受制于水热条件的WSOC分子量分布可能是影响样品紫外特征地域分异的主要因素。 Summary UV VIS spectroscopy and molecular size distribution of water soluble organic carbon (WSOC) of 45 soil samples collected from the eastern part of China were determined. Correlation between relative molicular size of WSOC and ratio of absorbance at 250 nm and 365 nm (E2/E3) together with UV absorbance intensity per unit carbon at 240 nm (E/TOC) were calculated. Also, same analyses were performed on fulvic acids extracted from part of the soil samples. It was found that there was a significant negtive correlationship between E2/E3 and molecular size of WSOC, while a significant positive correlationship existed between E/TOC and molecular size of WSOC, which means that E2/E3 and E/TOC could be used to study molecular size distribution of WSOC. But no similar relationships were found for fulvic acids. The reason for it needs to investigate further. It was also found that E/TOC showed a decreasing tendency from north to south and east to west in the studied area. Climate, mainly the temperature and precipation was thought to play an important role on spatial variation of UV VIS of WSOC.

关 键 词： 土壤 水溶性有机物 紫外光谱 地域分异

领　　域： [农业科学] [农业科学]