典型喀斯特山地小流域土地利用类型对土壤有机碳组分及其固碳效应的影响  

Effects of Land Uses on Soil Organic Carbon Fractions and Their Carbon Sequestration in a Typical Karst Small Mountain Watershed

作　　者：申佳龙 吴栎宏 李林霜 周远芳 杨孝民 SHEN Jialong;WU Lihong;LI Linshuang;ZHOU Yuanfang;YANG Xiaomin(Key Laboratory of Karst Georesources and Environment(Guizhou University),Ministry of Education,Guiyang 550025,P.R.China;College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,P.R.China)

机构地区：[1]喀斯特地质资源与环境教育部重点实验室(贵州大学),贵州贵阳550025 [2]贵州大学资源与环境工程学院,贵州贵阳550025

出　　处：《生态环境学报》2025年第3期358-367,共10页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(42203078);贵州大学自然科学专项(特岗)科研基金项目(202204);贵州大学大学生创新创业训练计划项目(gzuxc2023135)。

摘　　要：研究喀斯特山区不同土地利用类型下土壤有机碳的动态变化对于发挥喀斯特山区在实现碳中和目标中的作用具有重要意义。以典型喀斯特山区撂荒地、耕地、板栗林地、灌丛林地等4种常见的土地利用类型为研究对象,分别采集不同土地利用类型下0-20、20-40、40-60、60-80、80-100 cm深度土层的土壤样品,采用硫酸-重铬酸钾外加热氧化法和修正后的硫酸水解法将土壤总有机碳(SOC)划分为活性有机碳(LOC)和惰性有机碳(ROC)组分,以探讨土地利用类型对土壤有机碳不同组分及其固碳效应的影响。研究结果显示,在相同深度土层中,不同土地利用类型间的LOC储量并无显著性差异,而SOC和ROC储量在20-40 cm和80-100 cm土层中则具有显著性差异。在不同土地利用类型之间,灌丛林地具有较高的SOC储量和ROC储量,表明其固碳效应相对较强;由于荒地具有较低的ROC储量和较高的LOC储量,因此其固碳效应相对较弱。上述研究结果表明,在不同深度范围的土层中土地利用类型对LOC和ROC组分的影响并不完全相同;此外,通过加强土地资源管理,减少或杜绝耕地弃耕抛荒现象可提高喀斯特山区的土壤固碳潜力。研究结果可为优化喀斯特山区土地管理,从而提高喀斯特山区土壤固碳效应提供科学参考。In the context of global climate change,understanding the dynamic changes in soil organic carbon(SOC)under different land use types in karst mountainous areas is of great significance for leveraging these regions to achieve carbon neutrality.This study investigated four common land use types in a typical karst mountainous area:abandoned land,cultivated land,chestnut forest land,and shrub land.Soil samples were collected at five depths(0–20,20–40,40–60,60–80,and 80–100 cm)for each land-use type to explore the effects of land-use type on soil organic carbon fractions and their carbon sequestration.The total SOC,labile organic carbon(LOC),and recalcitrant organic carbon(ROC)were determined using the sulfuric acid-potassium dichromate external heating oxidation method,followed by fractionation using a modified sulfuric acid hydrolysis method.The results showed that LOC storage did not significantly differ among land use types at any soil depth,whereas significant differences in SOC and ROC storage were observed in the 20–40 cm and 80–100 cm soil layers.Among the land use types,shrubs exhibited relatively high SOC and ROC storage,indicating a stronger carbon sequestration potential.However,although abandoned land has relatively high SOC storage,its carbon sequestration might be weak because of its higher LOC storage and lower ROC storage.Our study indicated that the effects of land use on the LOC and ROC fractions varied with soil depth.Furthermore,the soil carbon sequestration potential in karst mountainous areas can be improved by enhancing land management practices to prevent or reduce the abandonment of cultivated lands.The results of this study can provide a scientific reference for the optimization of land management and the enhancement of soil carbon sequestration in karst mountainous areas.

关 键 词：喀斯特山区 土地利用类型 土壤有机碳 活性有机碳 惰性有机碳 

分 类 号：X144[环境科学与工程—环境科学]