在一个温带的日本雪松树林中的湿光合作用
Linjie Jiao1,2, Yoshiko Kosugi1, Ayaka Sakabe1,3
1Forest Hydrology Laboratory, Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Tree physiology
|April 10, 2024
概括
在日本的树林中,湿光合作用主要发生在降雨后,而不是降雨期间. 低轴叶面 (50%) 的部分湿优化了二氧化碳吸收模型,这对于了解森林碳循环至关重要.
科学领域:
- 生态生态学 生态生态学
- 森林科学 森林科学 森林科学
- 植物生理学 植物生理学
背景情况:
- 温带针叶树林在碳循环中发挥着至关重要的作用.
- 了解降雨期间和之后的树冠光合作用对于气候变化影响评估至关重要.
- 叶子湿度对森林生态系统中的气体交换的影响尚不完全理解.
研究的目的:
- 阐明温带针叶树林中湿光合作用的机制和意义.
- 评估叶截断对降雨期间和降雨后光合作用的影响.
- 通过结合降雨效应来改善生态系统碳交换模型.
主要方法:
- 持续的生态系统二氧化碳流观测,使用旋转共变率方法.
- 封闭路径气体分析仪在日本的树林中部署了三年.
- 观察到的净生态系统交换与土壤-植被-大气转移多层模型模拟的比较.
主要成果:
- 湿的二氧化碳吸收主要是在降雨后的时期观察到的,而不是在降雨期间.
- 多层模型模拟最好地预测了净生态系统交换,假设叶面湿面比率为50%.
- 在假设分别没有或完全轴叶面湿度时,模型对二氧化碳吸收的高估/低估发生了.
结论:
- 在降雨事件期间,日本树叶的斜轴表面仅部分湿.
- 部分湿可能保持口腔的开放,允许低水平的光合作用.
- 这些发现对于评估降雨对森林碳循环的影响和完善气候模型至关重要.
相关概念视频
C4 Pathway and CAM
45.5K
Most plants use the C3 pathway for carbon fixation. However, some plants, such as sugar cane, corn, and cacti that grow in hot conditions, use alternative pathways to fix carbon and conserve energy loss due to photorespiration. Photorespiration is the process that occurs when the oxygen concentration is high. Under such conditions, the rubisco enzyme in the Calvin cycle binds O2 instead of CO2, which halts photosynthesis and consumes energy.
C4 Pathway
The C4 pathway is used by plants such as...
C4 Pathway
The C4 pathway is used by plants such as...
45.5K
Adaptations that Reduce Water Loss
25.5K
Though evaporation from plant leaves drives transpiration, it also results in loss of water. Because water is critical for photosynthetic reactions and other cellular processes, evolutionary pressures on plants in different environments have driven the acquisition of adaptations that reduce water loss.
25.5K
Epiphytes, Parasites, and Carnivores
13.0K
Plants often form mutualistic relationships with soil-dwelling fungi or bacteria to enhance their roots’ nutrient uptake ability. Root-colonizing fungi (e.g., mycorrhizae) increase a plant’s root surface area, which promotes nutrient absorption. While root-colonizing, nitrogen-fixing bacteria (e.g., rhizobia) convert atmospheric nitrogen (N2) into ammonia (NH3), making nitrogen available to plants for various biological functions. For example, nitrogen is essential for the...
13.0K
Photosystem I
62.1K
Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
62.1K
Photosystem II
70.3K
The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
70.3K
The Calvin Benson Cycle
4.5K
Ribulose 1,5- bisphosphate carboxylase/oxygenase (RuBisCo) is a critical enzyme that catalyzes carbon dioxide assimilation during photosynthesis. However, it is an inefficient enzyme, having an extremely slow catalytic rate. A typical enzyme can process about a thousand molecules per second; however, RuBisCo fixes only around three-carbon dioxides per second. Photosynthetic cells compensate for this slow rate by synthesizing very high amounts of RuBisCo, making it the most abundant single...
4.5K


