大气-土壤碳转移作为土壤深度的函数
Jérôme Balesdent1, Isabelle Basile-Doelsch2, Joël Chadoeuf3
1Aix-Marseille Université, CNRS, IRD, INRA, Coll France, CEREGE, Aix en Provence, France. jerome.balesdent@inra.fr.
Nature
|July 12, 2018
概括
土壤有机碳的深层储存对气候和农业至关重要. 最近的碳融入主要发生在浅层土壤中,而不是深层地下,影响土壤碳管理策略.
科学领域:
- 土壤科学
- 气候科学
- 生态学
背景情况:
- 土壤有机碳 (SOC) 交换影响气候和农业生产力.
- 上层土壤的碳动态已被理解,但深层土壤的碳交换 (低于30厘米) 仍然不清楚.
- 这种知识缺口限制了有效的土壤碳管理和全球碳模型.
研究的目的:
- 将近期大气碳纳入整个土壤的概况量化.
- 分析最近在各种生态系统中加入的SOC的深度分布.
- 确定影响深层土壤碳封存的因素.
主要方法:
- 来自112个地点的稳定碳同位素特征的元分析 (1965-2015).
- 包括不同气候区的草原,森林和耕地.
- 分析碳融入深度及其与气候和土地利用的关系.
主要成果:
- 地下 (30-100厘米) 含有47%的SOC储量,但只有19%的新加入的SOC.
- 最近碳融入矿物土壤的中位深度在全球范围内为10厘米.
- 干旱度指数,而不是温度,更好地解释了深层土壤的碳分配;作物用地减少了表面SOC的结合.
结论:
- 土壤深度对SOC的动态和对气候和土地利用的反应产生重大影响.
- 目前的全球碳模型可能低估了深层土壤的碳封存.
- 需要多层土壤模块来更好地了解土壤与大气之间的碳交换.
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