从植物碳酸吸收推断的陆地光合作用
Jiameng Lai1, Linda M J Kooijmans2, Wu Sun3
1School of Integrative Plant Science, Cornell University, Ithaca, NY, USA.
Nature
|October 16, 2024
概括
地球上的光合作用或总初级产量 (GPP) 现在估计为157 PgC/年,高于以前的估计. 这种使用硫化碳的新 GPP 值有助于更好地了解碳循环反和热带森林的生产力.
科学领域:
- 生物地化学循环
- 植物生理学
- 气候科学
背景情况:
- 地球光合作用或总初级生产 (GPP) 是最大的碳流,但其全球规模和动态不确定.
- 现有的 GPP 估计有所不同,有些估计远低于从氧同位素和土壤呼吸中推断出来的估计,导致气候-碳循环反预测的不确定性.
- 基于卫星的GPP估计通常用于地球系统模型的基准测试,但可能低估了热带森林的生产力.
研究的目的:
- 开发一种使用碳化物作为二氧化碳扩散的标记物推断全球GPP的新方法.
- 解决目前GPP估计中的差异,并提高全球碳流量量化的准确性.
- 为了解和预测碳气候反提供更强大的生理基础.
主要方法:
- 使用碳酸 (COS) 作为从环境空气到叶子质体中的二氧化碳扩散的创新标记物.
- 在模型中明确纳入中粒细胞扩散,以准确量化碳酸吸收动态.
- 根据植物估计的硫化碳素摄入量推断的全球 GPP.
主要成果:
- 推断全球当代GPP为157 (±8.5) PgC yr-1,与氧-18同位素和土壤呼吸估计一致.
- 这个GPP值高于基于卫星光学观测的估计值 (120-140 PgC yr-1).
- 这种差异主要发生在热带雨林中,
结论:
- 碳化物追踪法提供了更可靠和更准确的全球GPP估计.
- 热带雨林的产量可能比目前的卫星GPP产品更高.
- 准确的 GPP 量化对于推进陆地碳汇和气候轨迹的理解和预测至关重要.
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