摘要
[目的]为揭示沙漠化土地植被重建过程中土壤无机碳固存效应及其环境影响机制。[方法]于榆林毛乌素沙地红石峡试验林场选择从半固定沙地(0 a)到植被恢复24~56 a的灌木和乔木固沙林地,量化0~10、10~20 cm土层全土总无机碳、水溶性无机碳及砂粒、粉粒、黏粒结合态无机碳组分的演变特征,同时解析无机碳组分库演变与植被、土壤理化性质因子的作用关系。[结果]随着固沙林植被恢复时间延长,2种固沙林土壤总无机碳及其组分质量分数均呈增长趋势,2个土层中均以粉粒结合态无机碳累积速率较高,在灌木和乔木林地0~20 cm土层固碳速率分别达0.13、0.17 g/(m^(2)·a),分别是水溶性无机碳及砂粒、黏粒结合态无机碳累积速率的5.0、1.2、7.0倍。植被恢复56 a时,乔木和灌木林地0~10 cm土层土壤总无机碳质量分数比半固定地分别增加12.4、17.9倍,增量为10~20 cm土层的1.4~1.8倍。同时,不同土壤组分中无机碳占比表现为粉粒碳>砂粒碳>水溶性碳>黏粒碳。进一步RDA和相关性分析表明,枯落物质量、土壤体积质量和Ca2+浓度变化是促进土壤无机碳及其组分固存的关键因素。[结论]固沙林恢复环境因子改善能显著促进总无机碳及矿物颗粒结合态无机碳的增加,尤其以粉粒吸附结合为无机碳主要固定形式,可能是沙漠化逆转土壤累积无机碳的重要机制之一。
[Objective]This study aims to reveal the soil inorganic carbon sequestration effects and the environmental impact mechanisms during the vegetation restoration process in desertified lands.[Methods]Shrub and tree sand-fixing forests from semi-fixed sandy land(0 a)to vegetation restoration of 24-56 a in the Hongshixia experimental forest farm of Yulin Mu Us Sandy Land were selected.The evolution characteristics of total inorganic carbon,water-soluble inorganic carbon,and inorganic carbon components in the 0-10 and 10-20 cm soil layers,as well as sand,silt and clay-bound inorganic carbon components,were quantified.Meanwhile,the relationships between the evolution of inorganic carbon component pools and vegetation and soil physicochemical properties were analyzed.[Results]As the restoration time of sand fixation forest prolonged,the contents of total inorganic carbon and its components in the soil of both types of sand fixation forest showed an increasing trend.Moreover,in both soil layers,the accumulation rates of mineral particle-bound inorganic carbon were relatively high.In the 0-20 cm soil layer of shrub land and arbor land,the carbon fixation rate reached 0.13 and 0.17 g/(m^(2)·a),which were on average 5.0,1.2 and 7.0 times higher than the accumulation rates of water-soluble inorganic carbon and sand particles and clay particles,respectively.When the vegetation was restored for 56 years,total inorganic carbon contents in the 0-10 cm soil layer of the arbor land and shrub land were 12.4 and 17.9 times greater than that of semi-fixed land,with increments 1.4-1.8 times those of the 10-20 cm soil layer.Meanwhile,the proportions of inorganic carbon in different soil components were ranked as silt-bound carbon>sand-bound carbon>water-soluble carbon>clay-bound carbon.Further RDA and correlation analyses indicated that changes in litter mass,soil bulk density,and Ca2+concentration were key factors promoting the sequestration of soil inorganic carbon and its components.[Conclusion]The improvement of environmental factors during sand-fixing forest restoration can significantly promote the increase of total inorganic carbon and mineral particle-bound inorganic carbon,with silt-bound carbon being the primary form of inorganic carbon fixation.This may be one of the important mechanisms for reversing accumulation of inorganic carbon in the soil during desertification.
作者
刘玥婷
郭雯娴
廖东亮
谢贇
马艳霞
刘洋
佟小刚
LIU Yueting;GUO Wenxian;LIAO Dongliang;XIE Yun;MA Yanxia;LIU Yang;TONG Xiaogang(College of Soil and Water Conservation Science and Engineering,Northwest A&F University,Yangling,Shaanxi 712100,China;College of Natural Resources and Environment,Northwest A&F University,Yangling,Shaanxi 712100,China;Datang Yangling Thermal Power Company Limited,Yangling,Shaanxi 712100,China)
出处
《水土保持学报》
北大核心
2025年第4期31-38,47,共9页
Journal of Soil and Water Conservation
基金
陕西省自然科学基金项目(2023-JC-ZD-10)
大唐杨凌热电有限公司光伏治沙科技项目(2023-ZH-054)
国家自然科学基金面上项目(42477324)。
关键词
土壤无机碳
土壤颗粒
植被重建
固碳
soil inorganic carbon
soil particles
vegetation restoration
carbon sequestration
