摘要
退耕还林作为改善生态环境、生态修复的重要措施,对土壤碳氮水循环起着关键作用。以祁连山南麓不同林分类型退耕林为研究对象,以未退耕的农田作为对照。研究0~100 cm土层土壤碳、氮、水的分布特征,分析其对不同林分类型退耕林的响应。结果表明:相较于农田,不同林分类型退耕林显著增加0~100 cm土层土壤碳氮含量及储量,降低土壤容重。退耕后不同林分0~100 cm土层平均土壤有机碳、全氮含量分别为20.26~22.53 g/kg和0.95~1.55 g/kg;储量分别为65.72~70.79、2.81~4.62 t/hm^(2)。退耕后MF(白桦-云杉混交林)0~100 cm土层土壤碳氮水储量均达到了最大,针阔混交林在该区域生态系统中具有显著优势。0~100 cm土层MF全氮含量的平均增幅是有机碳含量平均增幅的5.79倍,表明该区域退耕恢复过程中存在土壤碳氮积累的脱耦现象。土壤含水率与有机碳、全氮含量均有显著的正相关关系,两者之间有正向反馈效应。林分类型是调控土壤碳氮水固持能力的主要因素,深层碳氮水的贡献率不容忽视。在造林初期应采取土壤碳固持能力的措施,以维持退耕恢复长期过程中土壤碳氮水的平衡。
Afforestation is a crucial measure for ecological restoration,significantly influencing soil carbon and nitrogen cycles as well as water balance.This study examined different post-cropland afforestation types on the southern slopes of the Qilian Mountains,with refarmland the control.The distribution of carbon,nitrogen,and water in the 0~100 cm soil layer was analyzed to assess the response to various forest types.Results indicated that compared torefarmland,all forest types significantly increased carbon and nitrogen content and stocks in the 0~100 cm layer,while reducing soil bulk density.After afforestation,the mean Soil Organic Carbon(SOC)and Total Nitrogen(TN)contents ranged from^(2)0.26 to 22.53 g/kg and 0.95 to 1.55 g/kg,respectively,with corresponding stocks of 65.72~70.79 t/hm^(2) and 2.81~4.62 t/hm^(2).The mixed forest exhibited the highest carbon,nitrogen,and water stocks in the 0~100 cm layer,demonstrating its significant ecological advantage in this region.This suggests that forest type is a key factor affecting soil carbon,nitrogen,and water dynamics.The average increase in Total Nitrogen(TN)content in the mixed forest was 5.79 times greater than that of Soil Organic Carbon(SOC),highlighting a decoupling of carbon and nitrogen accumulation during the restoration process.Soil water content was positively correlated with both SOC and TN,with feedback effects observed between these variables.Stand type is the main factor regulating soil carbon,nitrogen and water retention ability,and the contribution rate of deep carbon,nitrogen and water cannot be ignored.In the early stage of afforestation,measures should be taken to maintain the balance of soil carbon,nitrogen and water in the process of long-term restoration.
作者
辛继林
林成清
邵亚茹
巩建伟
张永坤
Xin Jilin;Lin Chengqing;Shao Yaru;Gong Jianwei;Zhang Yongkun(College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,Qinghai,China;State Key Laboratory of Sanjiangyuan Ecology and Plateau Agriculture and Animal Husbandry,Qinghai University,Xining 810016,Qinghai,China;Qinghai Yellow River Upstream Hydropower Development Co.,Ltd.Yangqu Branch,Hainan Prefecture 813301,Qinghai,China)
出处
《绿色科技》
2025年第2期75-81,143,共8页
Journal of Green Science and Technology
关键词
祁连山南麓
退耕林分
土壤有机碳
碳氮储量
Southern Slopes of the Qilian Mountains
afforested land
soil organic carbon
carbon and nitrogen storage
