从化石叶子中估计碳同化率,并将其应用于米奥森中期的克拉基亚森林
Melanie R Cham1, Alexander J Lowe2,3, Dana L Royer1
1Department of Earth and Environmental Sciences, Wesleyan University, Middletown, 06459, Connecticut, USA.
American journal of botany
|August 11, 2025
概括
我们开发了一种新方法,用气交换模型来估计化石植物中的叶子碳同化 (A). 这种方法准确地重建了古代植物的A,揭示了植物进化和碳循环的洞察力.
科学领域:
- 古植物学是古植物学.
- 植物生理学 植物生理学
- 生物地质化学生物地质化学
背景情况:
- 叶子碳同化 (A) 对植物经济和全球碳循环至关重要.
- 以前估计化石A的方法依赖于间接的代理,比如最近的活着的亲属或叶脉密度.
研究的目的:
- 提出一种新的气体交换建模方法,用于在化石植物中重建叶子碳同化 (A).
- 将这种方法应用于克拉基亚植物中的米奥森时代的生苗.
主要方法:
- 使用气体交换建模,包括口腔特征,叶子稳定同位素 (δ13C) 和估计的大气CO2 .
- 将该方法应用于来自中米欧纪克拉基亚植物群的十种现存和九种化石血管种种类.
主要成果:
- 重建的现存种类的A估计与测量值密切匹配 (R2 = 0.89).
- 化石种群显示中位数重建的A范围为9.5-21.7μmol m-2 s-1,具有很高的不确定性.
- 当二氧化碳水平被固定在抽样时间范围内时,可以通过更紧密的置信区间实现A的相对排名.
结论:
- 在与快速生长或沿海息地 (如Castanea,Platanus) 相关的化石种群中重建的高叶碳同化 (A).
- 验证了对不太了解的化石种类 (例如,Quercus simulata) 的先前生态解释.
- 该方法为植物功能的古生态重建提供了一个强大的工具.
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