摘要
土壤CO_(2)是岩溶碳循环的核心驱动因子之一。以广西桂林丫吉岩溶试验场土壤剖面为例,利用高分辨率监测技术对不同土壤深度的温度、水分和CO_(2)进行监测,解析土壤剖面中CO_(2)含量的动态变化机理及其影响因素。季节尺度上,土壤温度是影响土壤CO_(2)含量的主要因素。土壤温度与大气温度变化趋势一致,表层土壤有明显的昼夜变化,而深层土壤则表现出多日连续性变化。在长时间尺度下,土壤温度越高,土壤CO_(2)含量也越高。短时间尺度上,土壤水分则是影响土壤CO_(2)含量的主要因素。降水前,土壤水分较低,降水后会刺激土壤CO_(2)以脉冲形式释放;而土壤水分较高时,降水则会降低土壤CO_(2)含量。特别是在干旱条件下,降水能够显著提高土壤CO_(2)含量,称为“桦木效应”。降水情景下,不同降水强度对土壤CO_(2)含量的影响不同。短时强降水后,土下10 cm处的CO_(2)含量(CO_(2)-10)迅速升高,土下40、90 cm处的CO_(2)含量(CO_(2)-40、CO_(2)-90)变化较小。持续性降水则会导致表层CO_(2)-10先升高后降低,CO_(2)-90逐渐减少。土壤CO_(2)含量的变化还受到土壤分层特性的影响。表层土壤植物根系密集,CO_(2)含量较高;而深层土壤孔隙度小、扩散性低,CO_(2)含量随深度增加而升高。本研究结果可为全球岩溶碳循环研究提供科学指导。
Soil CO_(2)is a key driving factor in the karst carbon cycle.The soil profile of Yaji karst test site in Guilin,Guangxi Province was selected as a case study.High-resolution monitoring technology was employed to measure temperature,moisture,and CO_(2)levels at various soil depths.The analysis focused on the dynamic mechanisms and influencing factors of CO_(2)content within the soil profile.At the seasonal scale,soil temperature is the primary factor influencing soil CO_(2)concentration.Soil temperature corresponded with atmospheric temperature,exhibiting pronounced diurnal variations at the surface level,while deeper soil layers displayed continuous changes over multiple days.On long time scales,higher soil temperatures correspond to increased soil CO_(2)concentrations.Conversely,on shorter time scales,soil moisture is the primary factor affecting soil CO_(2)levels.Prior to precipitation,soil moisture levels are low.Following precipitation,soil CO_(2)is released in pulses.Conversely,when soil moisture is high,precipitation results in a decrease in soil CO_(2)content.Notably,under drought conditions,precipitation can substantially elevate soil CO_(2)levels,a phenomenon known as the“birch effect”.Under varying precipitation scenarios,different precipitation intensities exert distinct effects on soil CO_(2)content.Following a brief period of heavy rainfall,CO_(2)-10 levels increased rapidly,while CO_(2)-40 and CO_(2)-90 exhibited minimal changes.Prolonged precipitation resulted in an initial rise in CO_(2)-10,followed by a decline,whereas CO_(2)-90 gradually decreased.Changes in soil CO_(2)content are influenced by the characteristics of soil stratification.The root systems of plants in the topsoil are dense,resulting in elevated CO_(2)levels.Conversely,deep soils exhibit low porosity and diffusion rates,leading to an increase in CO_(2)content with depth.The findings provide scientific guidance for understanding the global karst carbon cycle.
作者
池福祥
郭永丽
刘艺飞
张宁
谢银财
于奭
MITJA Prelovsek
CHI Fu-xiang;GUO Yong-li;LIU Yi-fei;ZHANG Ning;XIE Yin-cai;YU Shi;MITJA Prelovsek(College of Earth Sciences,Guilin University of Technology,Guilin 541006,China;Institute of Karst Geology,Chinese Academy of Geological Sciences/Key Laboratory of Karst Dynamics,MNR and GZAR/International Research Centre on Karst under the Auspices of UNESCO/National Center for International Research on Karst Dynamic System and Global Change,Guilin 541004,China;Guangxi Pingguo Karst Ecosystem National Observation and Research Station,Pingguo 531406,China;Karst Research Institute,Slovenian Academy of Sciences and Arts,Postonja SI-6230,Slovenia)
出处
《科学技术与工程》
北大核心
2025年第30期12813-12825,共13页
Science Technology and Engineering
基金
广西自然科学基金(2023GXNSFAA026473,桂科AB25069498,2022GXNSFAA035604)
中国地质科学院基本科研业务费项目(2023019)
国家自然科学基金国际合作与交流项目(42261144672)
中国地质调查项目(DD20230547)
自然资源部自然资源科技战略研究项目(2023-ZL-23)。
