树环中的氧同位素可以用来检测胃对全球变化的反应吗?
Imogen Carter1, Roel Brienen1, Manuel Gloor1
1School of Geography, University of Leeds, Leeds, UK.
Global change biology
|November 15, 2025
概括
树环氧同位素 (δ18Otrc) 可能无法可靠地表明由于CO2升高而导致的口腔导电率 (gs) 的长期变化. 像VPD和温度这样的环境因素显著影响 δ18Otrc趋势,复杂化了gs的解释.
科学领域:
- 植物生态生理学植物生态生理学
- 古气候学 古气候学
- 同位素地质化学 同位素地质化学
背景情况:
- 胃导电性 (gs) 控制植物气体交换,但其对二氧化碳增加和气候变化的长期反应仍有争议.
- 树环稳定氧同位素 (δ18Otrc) 建议反映过去的gs,但它们对环境驱动因素的敏感性需要评估.
- 之前使用 δ18Otrc 的研究表明,自工业化前以来,gs 的变化很小,但这一点受到质疑.
研究的目的:
- 为了评估树环氧同位素 (δ18Otrc) 对于在二氧化碳和气候变化上升下的口腔导电率 (gs) 变化的敏感性.
- 为了评估蒸汽压力缺陷 (VPD) 和温度对 δ18Otrc 趋势的影响,独立于 gs.
- 确定 δ18Otrc 的可靠性,以推断长期 gs 趋势.
主要方法:
- 利用当前的理论模型来模拟 δ18Otrc 趋势.
- 自20世纪初以来,分析了gs,VPD和温度的时间变化对δ18Otrc的影响.
- 研究了Péclet效应在将gs变化与 δ18Otrc.联系中的作用.
主要成果:
- 在gs的时间变化只会显著影响干燥气候中的δ18Otrc趋势,而Péclet效应则存在.
- VPD 和温度的增加对 δ18Otrc 趋势的影响要大得多,而不是 gs 变化.
- δ18Otrc检测gs变化的灵敏度有限,特别是在非Péclet条件下.
结论:
- 从 δ18Otrc 解释长期的 gs 趋势需要谨慎,因为有混的环境因素.
- VPD 和温度是 δ18Otrc 趋势的主要驱动因素,使得对 gs 的明确归因具有挑战性.
- 未来的研究应该改进方法来解脱gs,VPD和温度的影响,以准确地重建古气候.
相关概念视频
Global Climate Change
28.7K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
28.7K
Regulation of Transpiration by Stomata
30.8K
During photosynthesis, plants acquire the necessary carbon dioxide and release the produced oxygen back into the atmosphere. Openings in the epidermis of plant leaves is the site of this exchange of gasses. A single opening is called a stoma—derived from the Greek word for “mouth.” Stomata open and close in response to a variety of environmental cues.
30.8K
Oxygenic Photosynthesis
690
Oxygenic photosynthesis is a fundamental process in which light energy is harnessed to drive the oxidation of water, leading to the production of molecular oxygen (O₂), adenosine triphosphate (ATP), and nicotinamide adenine dinucleotide phosphate (NADPH). This process is essential for sustaining aerobic life on Earth and is primarily carried out by cyanobacteria, algae, and plants. The core of oxygenic photosynthesis lies in the thylakoid membranes, where chlorophyll pigments facilitate...
690
Responses to Drought and Flooding
11.9K
Water plays a significant role in the life cycle of plants. However, insufficient or excess of water can be detrimental and pose a serious threat to plants.
11.9K
The Calvin Cycle
82.7K
OverviewOxygenic photosynthesis plays a central role in the global carbon and oxygen cycles. The carbohydrates produced support nearly all food webs, while the oxygen by‑product enables aerobic life.Light‑dependent and light‑independent reactionsPhotosynthesis occurs in two main stages, each in a different part of the chloroplast: light‑dependent reactions and light‑independent reactions, also called the Calvin‑Benson cycle or simply the Calvin...
82.7K
Oxygen Requirements and Growth Patterns
1.1K
Microorganisms exhibit diverse oxygen requirements and growth patterns driven by their metabolic strategies and environmental adaptations. Oxygen, while essential for many organisms, can also be toxic under certain conditions, shaping how microorganisms grow and survive.Oxygen Requirements of MicroorganismsMicroorganisms are classified based on their ability to use or tolerate oxygen:● Obligate aerobes like Mycobacterium tuberculosis need oxygen for energy production, as it serves as the...
1.1K


