论文部分内容阅读
为阐明黄土高原典型区域土壤轻组有机碳(LFOC)和重组有机碳(HFOC)含量随土壤类型、土层和土地利用方式的变化规律,分析了从北向南依次分布的干润砂质新成土(神木)、黄土正常新成土(延安)和土垫旱耕人为土(杨凌)等典型土壤剖面(0～200 cm)LFOC和HFOC含量及分布特征。结果表明,从南到北,土壤LFOC和HFOC含量均显著下降(P<0.05),整体来看,黄土高原典型区域土壤LFOC含量占有机碳比例偏低;LFOC含量及在土壤有机碳中的分配比例随土层加深而递减,其比例变化范围为1%～26%;土地利用方式对浅层土壤LFOC和HFOC含量影响较为显著,草地土壤0～60 cm土层LFOC和HFOC含量均高于同层次农田土壤(P<0.05),60 cm土层以下差异不显著;土壤LFOC和HFOC含量与微生物量碳、微生物量氮含量均呈极显著正相关关系(P<0.01),前者的相关性系数更高,分别为0.841和0.507,表明土壤LFOC与微生物关系非常密切,是土壤微生物重要的碳和能量来源,极易受土地利用方式和微生物活性影响,同时表明用LFOC的变化更能快速有效地说明土壤碳库的变化规律。
In order to clarify the variation of soil light fraction organic carbon (LFOC) and recombinant organic carbon (HFOC) with soil types, soil layers and land use patterns in typical areas of the Loess Plateau, LFOC and HFOC content and distribution characteristics of typical soil profiles (0 ~ 200 cm), such as soil (Shenmu), normal new loess (Yan’an) and soil cover (Yangling) The results showed that the contents of LFOC and HFOC in soil decreased significantly from south to north (P <0.05). On the whole, the proportion of LFOC to total organic carbon was low in the typical area of the Loess Plateau. The content of LFOC and its distribution in soil organic carbon The proportion of LFOC and HFOC content in the shallow soil layer was significantly higher than that in the shallow soil layer. The contents of LFOC and HFOC in 0-60 cm soil layer in grassland were higher than those in the same layer (P <0.05), but there was no significant difference below 60 cm soil layer. Soil LFOC and HFOC contents had significant positive correlation with microbial biomass carbon and microbial biomass nitrogen (P <0.01), and the correlation coefficient Which is 0.841 and 0.507 respectively, which indicates that soil LFOC is closely related to microorganisms and is an important source of carbon and energy for soil microorganisms. It is highly influenced by land use patterns and microbial activities, and shows that changes in LFOC can be more effectively and rapidly Explain the variation of soil carbon pool.