半干旱生态系统对全球碳循环年间变化的贡献
Benjamin Poulter1, David Frank2, Philippe Ciais3
11] Montana State University, Institute on Ecosystems and the Department of Ecology, Bozeman, Montana 59717, USA [2] Laboratoire des Sciences du Climat et de l'Environnement (LSCE), CEA CNRS UVSQ, 91191 Gif Sur Yvette, France.
Nature
|May 23, 2014
概括
陆地和海洋吸收化石燃料的排放量,但半干旱地区,特别是澳大利亚,在2011年由于降雨量增加而导致了创纪录的陆地碳汇. 这凸显了半干旱生物群在全球碳循环变化中的日益重要.
科学领域:
- 地球系统科学 地球系统科学
- 气候科学 气候科学
- 生态生态学 生态生态学
背景情况:
- 陆地生物圈和海洋充当关键的碳汇,缓解化石燃料排放导致大气二氧化碳 (CO2) 的增加.
- 大气二氧化碳度的年间变化主要归因于陆地生态系统过程,特别是热带雨林.
- 了解土地碳汇的驱动因素对于准确的全球碳预算会计至关重要.
研究的目的:
- 为了研究过去30年陆地碳汇的演变.
- 确定2011年观察到的异常大的陆地碳汇背后的机制.
- 评估不同生物体在全球碳循环变化中的作用变化.
主要方法:
- 使用了陆地生物地质化学模型.
- 采用了大气二氧化碳逆转技术.
- 应用的全球碳预算会计方法.
主要成果:
- 通过三种独立的估计方法在2011年证实了土地的创纪录的碳汇.
- 确定了南半球半干旱植被的生长,特别是澳大利亚的生态系统,是2011年异常的主要驱动因素.
- 发现与拉尼娜现象相关的降雨量增加显著增加了澳大利亚生态系统的碳吸收,植物覆盖对降雨的敏感性显著增加.
结论:
- 由于碳池周转率较高,半干旱生物群是全球碳循环年间变化的越来越重要的驱动因素.
- 在未来,热带雨林可能会成为这种变化的不那么主要驱动因素.
- 需要进一步的研究,以了解半干旱地区积累的碳库存对分解或火灾事件的脆弱性.
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