| 摘要: |
| 【目的】测定色季拉山林线附近3种典型植被下土壤有机碳（SOC）及其组分含量，并分析其相关性以及与土壤理化性质的关系，探讨色季拉山典型植被类型下土壤有机碳及其组分特征，为该区域森林经营和管理提供参考。【方法】以西藏色季拉山林线3种典型植被类型（草甸、灌丛和乔木林）下0~20 cm土层土壤为研究对象，选择9个取样点采集0~10和10~20 cm土层土壤样品，测定土壤样品有机碳（SOC）及其组分（轻组有机碳（LFOC）、重组有机碳（HFOC）、可溶性有机碳（DOC）、微生物量碳（MBC）、颗粒有机碳（POC）和易氧化有机碳（EOC））的含量，并对土壤有机碳及其组分与土壤理化性质的相关性进行分析。【结果】草甸、灌丛和乔木林3种植被下，土壤SOC、MBC和HFOC含量表现为灌丛>乔木林>草甸，在灌木、乔木林和草甸土壤的0~10 cm土层，其SOC含量分别是96.34，95.85和66.15 g/kg，MBC含量分别为1 540.96，611.02和511.40 mg/kg，HFOC含量分别为61.75，58.65和41.02 g/kg；而在10~20 cm土层，其SOC含量分别为65.76，57.43和30.97 g/kg，MBC含量分别为289.90，184.02和84.15 mg/kg，HFOC含量分别为40.77，31.26和19.57 g/kg，且均以0~10 cm土层高于10~20 cm土层。土壤EOC、POC和LFOC含量表现为乔木林>灌丛>草甸，且均随着土层的加深而降低，在乔木林、灌丛和草甸土壤的0~10 cm土层，EOC含量分别为23.97，21.84和14.26 mg/kg，POC含量分别为30.11，24.94和12.96 g/kg，LFOC含量分别为12.55，1.93和1.21 g/kg；而在10~20 cm土层，EOC含量分别为11.83，10.62和4.68 mg/kg，POC含量分别为9.79，6.29和5.32 g/kg，LFOC含量分别为5.50，0.77和0.43 g/kg。草甸、灌丛和乔木林土壤的有机碳组分中，SOC与EOC、HFOC，EOC与POC和HFOC，以及POC与LFOC之间均呈显著正相关关系（P<0.05），且在乔木林土壤中，SOC与MBC、土壤含水率呈正相关关系，但其在灌丛林和草甸中相关性不明显。【结论】草甸、灌丛和乔木林土壤的有机碳及其组分之间存在差异性，说明色季拉山林线附近典型植被下土壤的有机碳及其组分受到植被类型的影响，且其分布具有表聚性。 |
| 关键词: 土壤有机碳 活性有机碳组分 典型植被 色季拉山林线 |
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| 基金项目:科技部国家野外科学研究观测站（生态系统）运行补助项目（2021-2025）;西藏高原森林生态教育部重点实验室研究生创新计划项目（XZA-JYBSYS-2021-Y11） |
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| Characteristics of soil organic carbon and its components under typical vegetation in Sejila forest line |
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ZHANG Meng,LU Jie,YU Deshui,et al
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| Abstract: |
| 【Objective】This study estimated soil organic carbon (SOC) and its components under typical vegetation near the Seljila Mountain,analyzed its correlation and relationship with soil environmental factors,and explored the characteristics of SOC and its components under typical vegetation types to provides the reference for the forest management and managment of the area. 【Method】Nine sampling sites were selected to collect soil samples in layers of 0-10 cm and 10-20 cm under three typical vegetation types of meadow,shrub and arbor forest at the Siljila forest line in Tibet. SOC and its components of light organic carbon (LFOC),recombinant organic carbon (HFOC),soluble organic carbon (DOC),microbial biomass carbon (MBC),particulate organic carbon (POC) and easily oxidized organic carbon (EOC) were determined and analyzed.The correlation between soil organic carbon and its composition and soil physicochemical properties was analyzed.【Result】SOC,MBC and HFOC contents were in the decreasing order of shrub>arbor forest>meadow.In 0-10 cm soil layer of shrub,arbor forest and meadow,SOC contents were 96.34,95.85 and 66.15 g/kg,MBC contents were 1 540.96,611.02 and 511.40 mg/kg,and HFOC contents were 61.75,58.65 and 41.02 g/kg,respectively.In the soil layer of 10-20 cm,SOC contents was 65.76,57.43 and 30.97 g/kg,MBC contents were 289.90,184.02 and 84.15 mg/kg,and HFOC contents were 40.77,31.26 and 19.57 g/kg,respectively.All contents in 0-10 cm soil layer were higher than those in 10-20 cm soil layer.EOC,POC and LFOC contents were in the decreasing order of arbor forest>shrub>meadow,and all decreased with the increase of soil layer.In the 0-10 cm soil layer of arbor forest,shrub and meadow,EOC contents were 23.97,21.84 and 14.26 mg/kg,POC contents were 30.11,24.94 and 12.96 g/kg,and LFOC contents were 12.55,1.93 and 1.21 g/kg,respectively.In the soil layer of 10-20 cm,EOC contents were 11.83,10.62 and 4.68 mg/kg,POC contents were 9.79,6.29 and 5.32 g/kg,and LFOC contents were 5.50,0.77 and 0.43 g/kg,respectively.There were positive correlations between SOC and EOC or HFOC,between EOC and POC or HFOC,and between POC and LFOC in the soil of meadow, shrub and arbor forests (P<0.05).In the soil of arbor forest,SOC was positively correlated with MBC and soil water content.Howerer,it was unknown in the irrigation forest and meadow.【Conclusion】There were differences in SOC and its components among meadow,shrub and arbor forests,indicating that they were affected by vegetation types and the distribution was surface clustering. |
| Key words: soil organic carbon active organic carbon component typical vegetation Sejila forest line |
