在现代升高的CO2环境下,对口腔分析的方法进行比较
Rebekah A Stein1, Nathan D Sheldon2, Selena Y Smith2
1Department of Chemistry & Physical Sciences, Quinnipiac University, Hamden, CT 06518, USA.
Life (Basel, Switzerland)
|January 23, 2024
概括
使用叶子胃口重建古老的二氧化碳 (CO2) 水平需要谨慎的方法. 胃口印记可能导致不准确的测量,这表明清除的叶子在古CO2研究中更可靠.
科学领域:
- 古植物学是古植物学.
- 古气候学 古气候学
- 植物生理学 植物生理学
背景情况:
- 叶子口腔调节气体交换 (二氧化碳和水),其形态在地质时间变化.
- 胃部的特征受到环境因素的影响,特别是大气中的二氧化碳度.
- 胃体参数用于重建过去的二氧化碳水平,通常使用气体交换模型和植物碳同位素数据.
研究的目的:
- 为了比较两种方法 (腐蚀性和非破坏性) 用于准备古CO2研究的叶片样本.
- 评估两种方法在不同类型的叶子 (叶和宽叶) 中对口腔参数测量的可比性.
- 用气体交换模型评估方法差异对古CO2重建的影响.
主要方法:
- 从已知大气二氧化碳水平的草本植物中收集了叶和宽叶标本.
- 使用腐蚀性 (清除) 方法和非破坏性 (打印) 方法准备的叶片样本.
- 测量了两种制备方法的口腔参数,包括口腔密度和防护细胞宽度 (GCW).
- 应用气体交换模型,利用测量的口腔参数重建过去的二氧化碳水平.
主要成果:
- 在腐蚀性和非破坏性方法之间,口腔密度的测量是可比的.
- 胃口尺寸测量,特别是护卫细胞宽度 (GCW),这两种方法之间无法比较.
- 使用口腔印记重建的二氧化碳水平 (由于GCW不准确) 显著超过了现代工厂测量的二氧化碳.
- 这种在二氧化碳重建中的偏差在针叶树和苗树的叶子中都被观察到.
结论:
- 与腐蚀性清除方法相比,非破坏性的口腔印记方法产生了不准确的防护细胞宽度测量.
- 来自印象的不准确的口腔尺寸测量在使用气交换模型重建古CO2水平时引入了显著的偏差.
- 为了准确的古 CO2 重建,建议使用化学清理的叶子而不是口腔印记.
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