摘要
土壤CO_(2)是岩溶作用的重要驱动力,也是陆地生态系统碳循环与岩溶碳循环的纽带。选择斯洛文尼亚典型岩溶区草地生态系统土壤剖面,开展大气与土壤CO_(2)、土壤水分与土壤温度等指标高分辨率监测,分析不同指标动态变化、分层效应及相互关系。结果表明,土壤温度、水分和CO_(2)含量变幅分别为3.8—12.9℃、26.9%—34.7%和(682—6760)×10^(-6)。土壤温度变化趋势与气温变化一致,上部土壤层随气温出现昼夜变化,响应敏感,下部土壤层则表现为多日变化;土壤水分变化主要受降雨控制,对降雨过程响应及时,不同深度分层效应显著,上部与下部含量较高,暗示草地根系有利于土壤水分保持,土岩界面的存在可能是下部保持较高水分的原因。土壤CO_(2)含量总体上受土温控制,随着深度增加逐渐升高。降雨过程中,不同深度土壤CO_(2)含量均有不同程度且较快速的升降现象,暗示雨水入渗土壤层后产生的活塞效应和随后的向下迁移是导致土壤CO_(2)含量陡升陡降的主要原因。从降雨过程大气CO_(2)含量有较大幅度降低的现象看,说明来自大气与土壤CO_(2)均参与了下伏碳酸盐岩的溶蚀过程,揭示在湿冷的地中海气候岩溶区,受生态系统控制的CO_(2)可为下伏碳酸盐岩溶蚀提供驱动力,其产生的碳汇可能是整个生态系统碳汇的重要组成部分。
Soil CO_(2)is a key driving force for karst processes, as well as the link between carbon cycle in terrestrial ecosystem and karst carbon cycle. A typical soil profile of meadow ecosystem in karst region of Slovenia was selected for the purpose of implementing high resolution monitoring of parameters, including contents of atmospheric CO_(2)and soil CO_(2), soil temperature and soil moisture, etc. The variations with days and at different depths of these parameters were analyzed, and the layered effect and parameters′ relationship also were discussed. The results showed that soil temperature, soil moisture and soil CO_(2)content ranged from 3.8℃ to 12.9℃, 26.9% to 34.7% and 682×10^(-6)to 6760×10^(-6)respectively. Soil temperature changed in accordance with air temperature;moreover, soil temperature at upper layer was much sensitive to air temperature thus presenting daily variation, while lower layer showed less daily fluctuation. Soil moisture mainly was controlled by rainfall and responded to rain events promptly. Layered effects at different depths were remarkable both in soil moisture and soil CO_(2). Soil moisture lowered and then raised with increase of soil depth, implying that grass roots were favored for soil moisture maintenance, and high moisture content at lower soil part might be caused by the halt of rock-soil interface below. Soil CO_(2)content was overall controlled by soil temperature, presenting a significant positive correlation each other. During the rain events, soil CO_(2)contents at various layers all exhibited behavior of “rapid ascending and descending”, suggesting that it was possibly resulted from the pulse effect caused by rainfall infiltration and consequent downward movement. Additionally, atmospheric CO_(2)content also showed a remarkable decrease during the rainfall, which could be explained that CO_(2)both from atmosphere and soil were involved in underlying carbonate rock dissolution. Rainfall processes can not only mitigate soil CO_(2)emission to atmosphere, but also
作者
章程
汪进良
肖琼
苗迎
Mitja Prelovsek
ZHANG Cheng;WANG Jinliang;XIAO Qiong;MIAO Ying;Mitja Prelovsek(Karst Dynamics Key Laboratory of Ministry of Natural Resources/Guangxi Zhuang Autonomous Region,Institute of Karst Geology,Chinese Academy of Geological Sciences,Guilin 541004,China;Karst Research Institute,Slovenian Academy of Sciences and Arts,Postonja SI-6230,Slovenia)
出处
《生态学报》
CAS
CSCD
北大核心
2022年第8期3288-3299,共12页
Acta Ecologica Sinica
基金
国家重点研发计划项目(2020YFE0204700)
科技部援外项目(KY201802009)
广西科技计划项目(桂科AD17129047)
中国科学院国际合作局项目(132852KYSB20170029-01)。
