广西喀斯特峰丛洼地造林对土壤有机碳、氮及其组分的影响  

Effects of afforestation on soil carbon and nitrogen fractions in the karst-cluster depression region of Guangxi

作　　者：周业恒 肖孔操[2,3] 夏世斌[1] 何寻阳[2,3] 李德军[2,3] ZHOU Ye-heng;XIAO Kong-cao;XIA Shi-bin;HE Xun-yang;LI De-jun(School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan,Hubei 430070,China;Key Laboratory of Agro-ecological Processes in Subtropical Region,Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha,Hunan 410125,China;Huanjiang Observation and Research Station for Karst Ecosystems,Huanjiang,Guangxi 547100,China)

机构地区：[1]武汉理工大学资源与环境工程学院,湖北武汉430070 [2]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,湖南长沙410125 [3]中国科学院环江喀斯特生态系统观测研究站,广西环江547100

出　　处：《农业现代化研究》2024年第2期316-325,共10页Research of Agricultural Modernization

基　　金：国家自然科学基金(U21A2007);广西“八桂学者”项目。

摘　　要：植树造林是促进退化喀斯特生态系统植被恢复同时提升生态碳汇的重要措施。目前,关于喀斯特峰丛洼地区造林对土壤碳氮组分及其生物化学稳定性的影响认识还很不足。本研究在广西喀斯特峰丛洼地区配对采集了玉米地及其邻近人工林表层(0~15 cm)和亚表层(30~45 cm)土壤样品各14组,采用酸水解法对土壤碳、氮组分(活性碳、氮组分I,活性碳、氮组分II和惰性碳、氮组分)进行了测定。研究表明,农田退耕造林20年后,表层和亚表层土壤总有机碳、全氮、活性碳组分、惰性碳组分、活性氮组分与惰性氮组分含量均有不同程度的增加。与农田相比,人工林土壤碳库活度(活性碳库/惰性碳库)整体降低,碳库稳定性(惰性碳占土壤总有机碳的比例)显著提高。逐步回归分析表明,根系生物量、碳酸钙和交换性钙离子是造林后土壤有机碳、氮及其组分含量增加的主控因子。Afforestation is an important strategy to promote vegetation restoration of degraded karst ecosystems while enhancing terrestrial carbon sequestration.To date,the effects of afforestation on soil carbon and nitrogen fractions and their biochemical stability in the karst-cluster depression region are poorly understood.In this study,14 sets of surface(0~15 cm)and sub-surface(30~45 cm)soil samples were collected from the maize field and its neighbouring plantation forests in the karst-cluster depression region of Guangxi,and the soil carbon and nitrogen fractions(labile carbon and nitrogen in pool I,labile carbon and nitrogen in pool II,and carbon and nitrogen in the non-lable pool)were determined using the acid hydrolysis method.The study showed that the contents of total organic carbon,total nitrogen,labile carbon and nitrogen pools,non-labile carbon and nitrogen pools in both surface and subsurface soils were significantly increased after 20 years of afforestation.The soil carbon pool activity(labile carbon pool/non-lable carbon pool)was significantly lower,but the carbon pool stability(non-labile carbon as a proportion of total soil organic carbon)was significantly higher in the plantation forest than in the maize field.Stepwise regression analyses showed that fine root biomass,calcium carbonate and exchangeable calcium ions were the main factors responsible for the increase of soil organic carbon,nitrogen and their fractions following afforestation.

关 键 词：造林 土壤有机碳 组分 稳定性 喀斯特峰丛洼地 

分 类 号：S153.6[农业科学—土壤学]