摘要
气候变化下频繁和严重的干湿循环事件对荒漠化草地生态系统的碳循环产生不可估量的影响。本研究2023年在短花针茅(Stipa breviflora Griseb)荒漠草原生长季初期(5—6月)和旺盛期(7—9月)设置了持续干旱及再润湿模拟试验,测定土壤总呼吸(Soil respiration,Rs)和土壤异养呼吸(Soil heterotrophic respiration,Rh),同时测量表层土壤温度、湿度和土壤微生物生物量碳含量,以及对样地进行了植被调查。结果表明:持续干旱及再湿润均显著影响Rs与Rh,生长季旺盛期Rs和Rh较生长季初期对土壤水分的响应更强烈;Rh是荒漠草原生态系统土壤碳排放的主要成分,占比约为63.0%,其受土壤微生物生物量碳含量影响显著;土壤自养呼吸(Soil autotrophic respiration,Ra)主要受植被生物量的影响,但由于土壤根际微生物受土壤温度和土壤水分的影响,Ra与地上和地下生物量线性关系不显著。本研究对评估荒漠草原生态系统碳平衡与量化土壤碳排放过程具有指导意义。
The frequency and severity of wet-dry cycle events are increasing under climate change,potentially exerting an immeasurable impact on the carbon cycle of desertification grassland ecosystems.The simulation experiments with continuous drought for 30 days and 50 days and rewetting were conducted during the early growing season(May-June)and peak period(July-September)of 2023 in Stipa breviflora Griseb desert steppe.Soil respiration(Rs)and soil heterotrophic respiration(Rh)were quantified.Simultaneously,measure⁃ments were taken for the surface soil temperature,soil moisture content and soil microbial biomass carbon were measured.In addition,the vegetation of the sample plots was investigated.The results showed that:(1)Both continuous drought and rewetting significantly impacted on Rs and Rh,with a stronger response of Rs and Rh to soil moisture content observed during the peak of the growing season compared to the early stage;(2)Rh repre⁃sented the primary process and form of carbon release in desert steppe ecosystems,accounting for approxi⁃mately 63.0%,while soil microbial biomass carbon content significantly influenced Rh;(3)Soil autotrophic res⁃piration(Ra)was primarily influenced by vegetation biomass,but there was no significant linear relationship between Ra and biomass due to the impact of soil temperature and soil moisture content on soil rhizosphere microorganisms.This study held guiding significance for assessing carbon balance in desert steppe ecosystems as well as evaluating soil carbon emissions.
作者
孙志强
韩春雪
李海港
SUN Zhi-qiang;HAN Chun-xue;LI Hai-gang(College of Grassland and Resource Environment,Inner Mongolia Agricultural University,Huhhot,Inner Mongolia 010018,China;Key Laboratory of Soil Quality and Nutrient Resources of Inner Mongolia Autonomous Region,Hohhot,Inner Mongolia 010018,China;Key Laboratory of Agricultural Ecological Safety and Green Development of Autonomous Higher Education Institutions,Hohhot,InnerMongolia 010018,China)
出处
《草地学报》
北大核心
2025年第2期535-546,共12页
Acta Agrestia Sinica
基金
国家自然科学基金(5210090125)
内蒙古自治区自然科学基金(2021BS05021)资助。
关键词
短花针茅荒漠草原
土壤异养呼吸
土壤自养呼吸
干旱胁迫
复湿
Stipa brevifloris desert steppe
Soil heterotrophic respiration
Soil autotrophic respiration
Drought stress
Re-wetting
作者简介
孙志强(1998-),男,汉族,内蒙古鄂尔多斯人,硕士,主要从事极端气候土壤碳排放过程研究,E-mail:szq1998@emails.imau.edu.cn;韩春雪(1990-),女,汉族,内蒙古赤峰人,博士,讲师,主要从事草原土壤生产力和碳排放过程的研究,E-mail:cxhan@imau.edu.cn;通信作者:李海港,E-mail:haigangli@imau.edu.cn。
