中亚热带森林土壤有机碳的海拔梯度变化  

Altitudinal Gradient of Soil Organic Carbon in Forest Soils in the Mid-Subtropical Zone of China

作　　者：吴小刚 王文平 李斌[2] 梁跃龙 刘以珍[2] WU Xiaogang;WANG Wenping;LI Bin;LIANG Yuelong;LIU Yizhen(Jiangxi Jiulianshan National Nature Reserve Administration,Ganzhou,Jiangxi 341700,China;College of Life Science in Nanchang University,Nanchang 330031,China)

机构地区：[1]江西九连山国家级自然保护区管理局,江西赣州341700 [2]南昌大学生命科学学院,南昌330031

出　　处：《土壤学报》2020年第6期1539-1547,共9页Acta Pedologica Sinica

基　　金：林业国家级自然保护区专项补助资金资助。

摘　　要：气候过渡区的山地森林土壤有机碳对气候波动的响应敏感,探讨气候过渡区森林土壤有机碳的海拔格局,是推演区域土壤碳库时空动态的关键内容。在南亚热带向中亚热带的气候过渡区江西九连山国家级自然保护区,根据不同土壤类型的海拔分布格局,沿海拔采集20个土壤剖面,分析土壤有机碳含量和土壤碳密度的海拔分布格局。结果表明:(1)不同土壤类型和深度均对土壤有机碳含量有影响,山地草甸土有机碳含量更高,达39.72±19.14 g·kg–1,土壤有机碳主要集中在0~40 cm,深度分布表现出“表聚现象”;(2)不同层次土壤有机碳含量对海拔的响应方式不一,上层土壤对海拔梯度变化响应更敏感,上层0~40 cm土壤有机碳随海拔升高而增加,下层40~100 cm土壤有机碳含量随海拔升高而降低;(3)土壤碳密度为10.64±0.72 kg·m^(–2),但不同海拔的土壤碳密度无显著差异。海拔对土壤有机碳含量分布产生影响,但随着土层深度增加,海拔对土壤有机碳含量的影响变小;而海拔对土壤有机碳密度格局无显著影响,并依此估算九连山自然国家级自然保护区森林土壤有机碳储量为1.426±0.096 Pg。【Objective】 Forest soil organic carbon (SOC) is an important component of the carbon storage in the forest ecosystem.Accumulation and storage of SOC in the forest soil can directly affect carbon budgeting in the terrestrial ecosystem and global carbonrecycling. SOC in mountain forest soils in the transitional climatic zone is sensitive to climatic change. So the subject of variation ofSOC along an altitudinal gradient is also a key topic concerning regional carbon dynamics. Hence, the survey of altitudinal gradient ofSOC in a transitional climate zone is far more valuable than that in a typical climate zone to predicting variation of regional SOC inresponse to climate changes. The objective of this study was to investigate effects of altitude on SOC so as to explain how carbon stocksdistributes in the subtropical transitional climate zone of East China. 【Method】 A total of 20 soil profiles were prepared along the altitude (179-1 410 m a.s.l.) in Jiangxi Jiulianshan National Nature Reserve, located just in the transitional climate zone from thesouth-subtropical zone to the mid-subtropical zone. Soil samples were collected separately from five layers (0-10 cm, 10-20 cm, 20-40cm, 40-60 cm and 60-100 cm) of each of the soil profiles (0-100 cm). After being air-dried, the samples were analyzed for soil organiccarbon content with the potassium bichromate oxidation titration method. Soil organic carbon density (SCOD) and soil organic carbonstocks (SOCS) were calculated. Along the altitude, red soil, red-yellow soil, yellow soil and meadow soil was distributed in sequence, soimpacts of altitude on SOCC and SBD (soil bulk density) could be explored by analyzing the two parameters in the four types of soils.Soil layer depth and soil type were two factors affecting SOCC and SBD and their impacts were analyzed with two-way Analysis ofVariance (two way- ANOVA);impact of soil type on SOCD was with ANOVA;and relationships of altitude with SOCC and SOCD werewith Pearson correlation analysis and nonlinear analysis, respec

关 键 词：土壤有机碳 土壤类型 海拔梯度 气候过渡区 

分 类 号：S714.2[农业科学—林学]