缙云山5种植被下土壤活性有机碳及碳库变化特征

为揭示重庆市缙云山不同植被下土壤活性有机碳及碳库分配特征，以该地区5种植被类型：阔叶林、针叶林、混交林、竹林和荒草地为研究对象，分析不同植被类型下各土壤层次中有机碳（Soil organic carbon, SOC）、微生物量碳(Microbial biomass carbon，MBC)、可溶性有机碳(Dissolved organic carbon，DOC)、易氧化有机碳(Readily oxidized organic carbon，ROC)含量及其土壤碳库的变化特征。结果表明：土壤有机碳和各活性有机碳组分含量及分配比例受到植被类型和土层深度的明显影响。土壤有机碳的平均含量在0~100 cm土层表现为竹林（16.74 g/kg）>阔叶林（12.62 g/kg）>草地(11.14 g/kg)>混交林（8.16 g/kg）>针叶林（5.98 g/kg），并随土层深度的增加而减小。竹林和阔叶林的微生物量碳和易氧化有机碳含量均明显高于混交林和针叶林，各植被在剖面上均表现出垂直递减规律，表现出明显的表聚效应。除草地，4种植被的土壤碳库管理指数随土层深度的加深而减小，均表现为表层(0~20 cm土层)最高。不同植被类型间，竹林的可溶性有机碳分配比例在各土壤层次均最小，整个土壤剖面均值仅为0.1%。由相关性分析可知，微生物量碳、易氧化有机碳、土壤总有机碳含量和土壤有机碳储量有着极其显著的相关性。因此，土壤微生物量碳和易氧化有机碳可以作为衡量亚缙云山森林不同植被土壤有机碳库变化的敏感性指标。

Variation Characteristics of Soil Active Organic Carbon and Carbon Pools Under Five Vegetation Types in Jinyun Mountain

In order to reveal the characteristics of soil active organic carbon and carbon pool allocation under different vegetations in Jinyun Mountain in Chongqing, five planted cover types in the area: broad-leaved forest, coniferous forest, mixed forest, bamboo forest and wild grassland were taken as research objects. The contents of soil organic carbon (SOC), microbial biomass carbon (MBC), dissolved organic carbon (DOC), and easily oxidized organic carbon (ROC) in each soil layer The changing characteristics of its soil carbon pool. The results show that the content and distribution ratio of soil organic carbon and each active organic carbon component are significantly affected by vegetation type and soil depth. The average content of soil organic carbon in the 0-100 cm soil layer is bamboo forest (16.74 g / kg)> broadleaf forest (12.62 g / kg)> grassland (11.14 g / kg)> mixed forest (8.16 g / kg)> needles Ye Lin (5.98 g / kg), and decreases with increasing soil depth. The contents of microbial biomass carbon and easily oxidized organic carbon in bamboo forest and broad-leaved forest were significantly higher than that in mixed forest and coniferous forest. Each vegetation showed a vertical decline rule on the profile, showing a significant surface aggregation effect. Except for grassland, the soil carbon pool management index of the 4 plantings decreased with the depth of the soil layer, and all showed the highest surface layer (0~20 cm soil layer). Among different vegetation types, the distribution ratio of soluble organic carbon in bamboo forests is the smallest in each soil layer, and the average value of the entire soil profile is only 0.1%. From the correlation analysis, we can see that there is an extremely significant correlation between microbial biomass carbon, easily oxidized organic carbon, soil total organic carbon content and soil organic carbon storage. Therefore, soil active organic carbon can be used as an important indicator to evaluate the dynamic changes of soil organic carbon pool.