EAPSI: Does Branch Photosynthesis Mitigate Water Loss in Tropical Trees During Drought?

该奖项支持四种热带树种在干旱和非干旱条件下树枝光合作用变化的研究。热带雨林是地球上最多产、最多样化的生物群落之一。然而，气候变化预计会增加热带雨林干旱的频率和严重程度。为了使植物在干旱中存活下来，它们必须继续进行光合作用，同时尽量减少水分的流失。这项研究旨在了解热带树木如何利用树枝光合作用来减少水分损失并在干旱中生存。虽然以前的研究已经测量了分支光合作用，但很少有人努力去理解或模拟干旱下的分支光合作用。这项研究将在澳大利亚昆士兰州的丹特里雨林观测站进行，由世界分支光合作用专家卢卡斯·切尔努萨克教授指导。光合作用所需的大部分二氧化碳是通过气孔获得的，气孔是树叶上的小气孔；然而，二氧化碳的增加是以水的损失为代价的。预计热带雨林干旱的严重程度和频率将随着气候变化而增加，这反过来将导致光合作用减少和植物死亡率增加。植物可以在减少水分流失的同时，通过分支光合作用进行光合作用，回收呼吸的二氧化碳。研究人员将在詹姆斯库克大学凯恩斯校区运营的丹特里雨林观测站进行实地工作。与Cernusak教授合作将是该项目的重要组成部分。Cernusak教授是研究树枝光合作用的世界级专家。这项研究将增加对热带树木如何应对和适应干旱压力的认识。此外，这项研究将提供分支光合作用的数学模型，可以应用于其他树种。该奖项由美国国家科学基金会和澳大利亚科学院共同资助，隶属于东亚和太平洋暑期研究所项目，支持美国研究生进行暑期研究。

This award supports research on how branch photosynthesis varies in four tropical tree species under drought and non-drought conditions. Tropical rainforests are some of the most productive and diverse biomes on Earth. However, climate change is expected to increase the frequency and severity of droughts in tropical rainforests. For plants to survive a drought they must continue to photosynthesize while minimizing water loss. This study aims to understand how tropical trees utilize branch photosynthesis to minimize water loss and survive droughts. While previous research has measured branch photosynthesis, little effort has gone into understanding or modeling branch photosynthesis under drought. The research will be conducted at the Daintree Rainforest Observatory in Queensland, Australia, under the direction of Professor Lucas Cernusak, a world expert in branch photosynthesis.Most CO2 for photosynthesis is obtained through stomata, small pores in the leaves; however, this CO2 gain comes at the expense of water loss. Drought severity and frequency in tropical rainforests is expected to increase with climate change, which in turn will lead to a decrease in photosynthesis and an increase in plant mortality. Plants can minimize water loss while still photosynthesizing through branch photosynthesis, which recycles respired CO2. The researcher will conduct field work at the Daintree Rainforest Observatory operated by James Cook University Cairns Campus. Collaboration with Professor Cernusak, a world expert in branch photosynthesis, will be an essential component of the project. This research will increase the knowledge of how tropical trees respond and adapt to drought stress. Additionally, this research will provide mathematical models of branch photosynthesis that can be applied to other tree species. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Australian Academy of Science.