{"title":"Seasonal and Interannual Variability of Soil Heterotrophic Respiration and Autotrophic Respiration in Typical Grassland of Inner Mongolia","authors":"Bingyan Jin, Yibo Yan, Xiaowen Wang, Xiujun Wang, Xianglan Li, Haiqing Song","doi":"10.1029/2024JG008651","DOIUrl":null,"url":null,"abstract":"<p>Considerable differences exist between soil heterotrophic respiration and autotrophic respiration in terms of variation and regulating factors. However, there is still a lack of evaluation of the differences between the two components in grasslands of arid and semi-arid regions under a changing climate. We developed a semi-process model separately for heterotrophic respiration and autotrophic respiration for the Inner Mongolian grassland of China to estimate their rates over seasonal and interannual cycles from 2002 to 2021. The models were calibrated with site-specific parameters and validated against independent field measurements. Our model results show stronger seasonal and interannual variability in autotrophic respiration than in heterotrophic respiration over 2002–2021. There was a significant increasing trend in most seasons at all three sites for autotrophic respiration (with the greatest slope in summer, i.e., 2.12–3.97 g C m<sup>−2</sup> yr<sup>−2</sup>), but only in winter for heterotrophic respiration at the southern typical grassland site (0.27 g C m<sup>−2</sup> yr<sup>−2</sup>). Soil temperature was responsible for the seasonal and interannual variability in heterotrophic respiration but plant growth responsible for the temporal variations of autotrophic respiration. Our results highlight that distinguishing between soil heterotrophic respiration and autotrophic respiration is of importance not only for better understanding of the carbon cycle in the grasslands but also for predicting how soil respiration responds to climate change in the future.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 7","pages":""},"PeriodicalIF":3.5000,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geophysical Research: Biogeosciences","FirstCategoryId":"93","ListUrlMain":"https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024JG008651","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Considerable differences exist between soil heterotrophic respiration and autotrophic respiration in terms of variation and regulating factors. However, there is still a lack of evaluation of the differences between the two components in grasslands of arid and semi-arid regions under a changing climate. We developed a semi-process model separately for heterotrophic respiration and autotrophic respiration for the Inner Mongolian grassland of China to estimate their rates over seasonal and interannual cycles from 2002 to 2021. The models were calibrated with site-specific parameters and validated against independent field measurements. Our model results show stronger seasonal and interannual variability in autotrophic respiration than in heterotrophic respiration over 2002–2021. There was a significant increasing trend in most seasons at all three sites for autotrophic respiration (with the greatest slope in summer, i.e., 2.12–3.97 g C m−2 yr−2), but only in winter for heterotrophic respiration at the southern typical grassland site (0.27 g C m−2 yr−2). Soil temperature was responsible for the seasonal and interannual variability in heterotrophic respiration but plant growth responsible for the temporal variations of autotrophic respiration. Our results highlight that distinguishing between soil heterotrophic respiration and autotrophic respiration is of importance not only for better understanding of the carbon cycle in the grasslands but also for predicting how soil respiration responds to climate change in the future.
土壤异养呼吸和自养呼吸在变异和调节因子方面存在较大差异。然而,在气候变化的条件下,干旱半干旱区草地中这两个组分之间的差异还缺乏评价。本文分别建立了内蒙古草原异养呼吸和自养呼吸的半过程模型,估算了2002 - 2021年异养呼吸和自养呼吸在季节和年际周期中的速率。这些模型使用特定地点的参数进行校准,并根据独立的现场测量进行验证。我们的模型结果显示,2002-2021年间,自养呼吸的季节性和年际变化强于异养呼吸。3个样地的自养呼吸在大多数季节都呈显著增加趋势(夏季坡度最大,为2.12 ~ 3.97 g C m−2 yr−2),而南方典型样地的异养呼吸仅在冬季坡度为0.27 g C m−2 yr−2)。土壤温度对异养呼吸的季节和年际变化负责,而植物生长对自养呼吸的时间变化负责。我们的研究结果强调,区分土壤异养呼吸和自养呼吸不仅对更好地了解草原的碳循环,而且对预测未来土壤呼吸如何响应气候变化具有重要意义。
期刊介绍:
JGR-Biogeosciences focuses on biogeosciences of the Earth system in the past, present, and future and the extension of this research to planetary studies. The emerging field of biogeosciences spans the intellectual interface between biology and the geosciences and attempts to understand the functions of the Earth system across multiple spatial and temporal scales. Studies in biogeosciences may use multiple lines of evidence drawn from diverse fields to gain a holistic understanding of terrestrial, freshwater, and marine ecosystems and extreme environments. Specific topics within the scope of the section include process-based theoretical, experimental, and field studies of biogeochemistry, biogeophysics, atmosphere-, land-, and ocean-ecosystem interactions, biomineralization, life in extreme environments, astrobiology, microbial processes, geomicrobiology, and evolutionary geobiology