Collaborative Research: Conifer leaf anatomy determines hydraulic functioning

合作研究：针叶树叶解剖结构决定水力功能

• 批准号: 1656731
• 负责人: Daniel Johnson
• 金额: $ 36.79万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2018-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1656731&HistoricalAwards=false
• 关键词: Collaborative; Research; Conifer; leaf; anatomy

Conifers are globally important, both ecologically and economically. Many conifer species have recently experienced extreme mortality events due to drought, fire and insect outbreaks. There is an urgent need to understand conifer physiology, and especially conifer needles - the organs responsible for carbon uptake and regulation of water loss. Conifers have an intriguing paradox in the link between their leaf anatomy and physiology: with such a simplistic, single-vein vascular system, how can they compete with broadleaf species or inhabit extreme environments? This project aims to understand how conifer leaf anatomy influences water transport and photosynthesis, and how needle water transport declines during drought. This information will then be used to develop a mechanistic model to help predict forest productivity and mortality in response to drought and other environmental challenges. The project will provide training for a postdoctoral researcher, a graduate student, and multiple undergraduate students. Also, in collaboration with the McCall Outdoor Science School, 5th and 6th grade students, their parents and teachers will participate in a workshop called "What happens inside a leaf?" To illustrate how cellular-level modifications can influence landscape processes, 3D-printed conifer needle models generated from X-ray imaging will be used. Anatomical models will be freely available through a website for teachers and students to 3D print hand-held models at schools, or as teaching kits for schools without access to 3D printing technology. Conifers inhabit some of the driest and coldest habitats where trees are found. Many conifer species are threatened by heat waves and droughts that induce physiological stress that can make them more vulnerable to pests and pathogens. Although most conifer leaves have only a single vein supplying water to the leaf, the internal anatomy outside the vein is incredibly diverse across the conifer phylogeny. The impact of this diversity on water transport and carbon uptake is unknown. The primary goal of this project is to develop a mechanistic framework to understand the influence of conifer leaf anatomy on leaf hydraulic conductance and photosynthetic capacity. This mechanistic understanding will be used to illuminate how conifers have adapted to arid and cold environments and have also been able to successfully compete with angiosperm species over evolutionary history. The project will combine state-of the art 3-dimensional imaging methods (high-resolution X-ray computed micro-tomography) with a hydraulic model and measurement of leaf hydraulic conductance to clarify the impact of conifer leaf internal anatomy on hydraulic function.

针叶树在生态和经济上在全球范围内都很重要。由于干旱，火灾和昆虫暴发，许多针叶树物种最近经历了极端的死亡事件。迫切需要了解针叶树生理学，尤其是针叶树针 - 负责碳吸收和调节水分流失的器官。针叶树在其叶子解剖学和生理学之间的联系中具有有趣的悖论：具有如此简单的单垂直血管系统，它们如何与阔叶物种竞争或居住在极端环境中？该项目旨在了解针叶树叶解剖学如何影响水的运输和光合作用，以及在干旱期间针水的运输如何下降。然后，将使用此信息来开发机械模型，以帮助预测森林生产力和死亡率，以应对干旱和其他环境挑战。该项目将为博士后研究人员，研究生和多名本科生提供培训。另外，与麦考尔户外科学学校合作，五年级和六年级的学生，他们的父母和老师将参加一个名为“叶子里发生什么？”的研讨会。为了说明细胞级修改如何影响景观过程，将使用3D打印的针叶树针模型。解剖模型将通过网站免费提供，供教师和学生提供学校的3D打印手持模型，或者作为学校教授套件，而无需使用3D打印技术。针叶树居住在发现树木的一些最干燥，最冷的栖息地。 许多针叶树物种受到诱发生理压力的热浪和干旱的威胁，这会使它们更容易受到害虫和病原体的影响。尽管大多数针叶树叶只有一个静脉为叶子供水，但在针叶树系统发育中，静脉外的内部解剖结构非常多样。这种多样性对水运输和碳吸收的影响尚不清楚。该项目的主要目标是开发一个机械框架，以了解针叶树叶解剖学对叶子液压电导和光合作用能力的影响。这种机械理解将用于阐明针叶树如何适应干旱和寒冷的环境，并在进化史上也能够成功与被子植物物种竞争。该项目将结合最新的3维成像方法（高分辨率X射线计算的微型摄影）与液压模型和测量叶子液压电导的测量，以阐明针叶叶内部解剖结构对液压功能的影响。