The potential for climate-induced disruption of plant-microbe symbioses along altitudinal gradients

随着气温的升高，物种正在向山上迁移。随着山脉向更高的海拔移动，物种之间重要的相互作用可能会中断，其后果尚不清楚。物种间相互作用产生的耦合动态可以对气候变化产生复杂的、意想不到的生态响应。新的物种反应可能通过改变影响碳循环的过程来反馈气候变化本身的速度。植物的真菌共生体，如内生真菌和菌根真菌，现在已经被充分证明可以影响植物对气候变化的适应能力。真菌也在碳循环中发挥关键作用，通过以顽固的形式储存碳和分解有机物质。因此，气候变化使植物和真菌相互作用脱钩的可能性值得密切关注。虽然植物在气候变化下的运动很容易观察到，但真菌物种的运动不明显，研究很少。该项目将评估植物-真菌共生在未来气候条件下变得不稳定的可能性，并测试单个植物物种和碳循环中断的后果。这个项目有四个主要组成部分。首先，将利用显微镜和DNA测序技术，沿着科罗拉多州落基山脉复制的海拔梯度，描述真菌共生体在植物叶片和根系上的分布。这项工作构成了世界上最大的真菌共生体的纵向调查。其次，一项由美国国家科学基金会资助的长达22年的变暖实验将首次用于测试真菌对气候变暖的反应是否符合它们沿自然海拔梯度的分布模式。第三，植物和真菌的互惠移植将模拟3°C温暖气候下的范围移动，并通过实验测试共生解耦的后果。第四，功能分析将评估被破坏的共生如何影响碳循环。更广泛的影响：大部分预算用于培训下一代科学家，包括新墨西哥大学（University of New Mexico）这个少数族裔占多数的机构中代表性不足的群体的学生。K-12扩展包括高中教师培训和课程开发，为服务不足的学校和儿童自然营地的共生讲习班和成人公民科学项目提供支持，通过落基山生物实验室。

Species are moving up mountainsides as temperatures rise. As ranges move to higher altitudes, important interactions between species may be disrupted, with as yet unknown consequences. The coupled dynamics arising from species interactions can produce complex and unanticipated ecological responses to climate change. Novel species responses may feed back on the rate of climate change itself by altering processes that influence carbon cycling.Fungal symbionts of plants, such as endophytes and mycorrhizal fungi, are now well documented to influence the resilience of plants to climate change. Fungi also play critical roles in carbon cycling, by storing carbon in recalcitrant forms and decomposing organic material. Therefore, the potential for climate change to decouple plant and fungal interactions deserves careful attention. While plant movement under changing climates is easily observed, movement of fungal species is inconspicuous and little studied. This project will gauge the potential for plant-fungal symbioses to become destabilized under future climates and test the consequences of disruptions for individual plant species and carbon cycling.This project has four major components. First, the distributions of fungal symbionts colonizing plant leaves and roots will be described along replicated elevation gradients in the Rocky Mountains of Colorado, using microscopy and DNA sequencing. This work constitutes the largest altitudinal survey of fungal symbionts anywhere in the world. Second, an NSF-funded, 22-year long warming experiment will be leveraged to test, for the first time, whether fungal responses to climate warming match their distributional patterns along natural, altitudinal gradients. Third, reciprocal transplants of plants and fungi will mimic range shifts under a 3°C warmer climate and experimentally test the consequences of symbiosis decoupling. Fourth, functional assays will evaluate how disrupted symbioses affect carbon cycling. Broader Impacts: A majority of the budget is allocated to training the next generation of scientists, including students from underrepresented groups at the University of New Mexico, a majority-minority institution. K-12 outreach includes high school teacher training and curriculum development for under-served schools and symbiosis workshops in a kids nature camp and adult citizen science program supported through the Rocky Mountain Biological Laboratory.