Collaborative Research: BoCP-Implementation: Alpine plants as a model system for biodiversity dynamics in a warming world: Integrating genetic, functional, and community approaches

美国东北部的山顶支持着独特的北极和高山植物生态系统，这些植物以孤立的小块形式存在于林线上方。据认为，这些植物群落自大约13,000年前冰川消退以来一直存在，在过去的自然气候变化和上个世纪人类造成的变暖中幸存下来。这些脆弱的生态系统具有重要的文化意义，每年都会吸引数以千计的徒步旅行者来到这些山峰。它们也对负责保护它们免受气候变化、践踏、过度使用和其他威胁的管理机构构成了挑战。与此同时，他们可能掌握着一些线索，说明孤立的小种群如何在气候变化时期幸存下来。答案在于植物本身，在于它们快速适应不断变化的环境的能力吗？或者，它们成功的秘诀是在基岩的隐蔽角落和缝隙里，这些地方在炎热的天气里提供了一个凉爽的避难所？随着时间的推移，这些山顶“岛屿”上的植物在多大程度上正在消失，甚至可能重新出现？为了回答这些问题，来自佛蒙特大学和缅因州大学的一组研究人员将采样阿迪朗达克山脉、佛蒙特州的绿色山脉、新汉普郡的怀特山和缅因州的卡塔丁的高山湖泊，分析古代植物的DNA，以了解自上一个冰河时代结束以来，物种是否真的存在了数千年。与此同时，他们将调查东北高山地区的现代植物，包括田间和实验花园。最后，研究人员将在一个展示高山植物和与它们共事的人的播客中分享他们的结果，以及一个新的人工智能驱动的应用程序(在东北阿尔卑斯山管理聚会的培训研讨会上展示)，该应用程序将帮助管理者和其他人就如何最好地管理这一重要的自然遗产做出明智的决定，以度过下一个世纪。这项工作的总体目标是帮助科学家、志愿者和管理人员了解如何更好地支持东北地区的高山植物，以及世界上其他稀有或孤立物种面临气候变化和其他威胁的地区。该项目将整合古生态学、群落生态学、特征生态学、种群基因组学和地理学的工具，以了解东北部高山植物群落是如何组装和持续存在的。研究小组聚焦于阿迪朗达克山脉(NY)、绿色山脉(VT)和怀特山脉(NH)以及卡塔赫丁山脉(ME)，将首先使用高山沉积物岩心的古代DNA在物种水平上表征过去约13,000年的植被动态。为了表征应对历史变暖的变化，他们将进行植物调查，通过比较现代植物区系和历史调查记录来估计上个世纪的物种周转。然后，该团队将结合来自普通花园实验、小气候传感器阵列、功能特征分析和种群基因组数据的合并建模的数据，以揭示过去和当代的人口动态，并阐明微避难所、表型可塑性和局部适应在推动千年、百年和十年时间尺度的生物多样性周转中的相对作用。这项研究将集中在代表主要高山植物功能类型(禾本科、杂草和矮灌木)的六个焦点分类群。由此产生的多维生物多样性数据将为预测模型提供信息，这些模型将在与过去已知的生物多样性动态进行测试后与区域管理人员共享。通过这种新颖的综合方法，该项目旨在通过在一个综合框架中量化气候避难所、集合种群过程、表型可塑性和适应能力的相对作用，提高对全球变暖中分散的种群中生物多样性动态的预测能力。该提议由变化中的星球上的生物多样性计划和既定的刺激竞争研究计划(EPSCoR)共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The mountaintops of the northeastern United States support unique ecosystems of Arctic and alpine plants, which exist as small, isolated patches above the treeline. It is thought that these plant communities have existed since the retreat of the glaciers approximately 13,000 years ago, surviving through the natural climate changes of the past as well as human-caused warming over the last century. These vulnerable ecosystems are culturally important, drawing thousands of hikers to these peaks every year. They also pose a challenge for the management agencies tasked with protecting them from climate change, trampling, overuse, and other threats. At the same time, they may hold clues about how small, isolated populations can survive periods of climate change. Does the answer lie in the plants themselves, in their ability to adapt quickly to changing environments? Or is the secret to their success in the sheltered nooks and crannies of bedrock, which provide a cool refuge during the heat? And to what extent are plants disappearing, and perhaps reappearing, on these mountaintop “islands” over time? To answer these questions, a team of researchers from the University of Vermont and the University of Maine will sample alpine lakes in the Adirondacks, the Green Mountains of Vermont, the White Mountains of New Hampshire, and Katahdin in Maine, analyzing the DNA of ancient plants to understand whether species have truly persisted in the thousands of years since the end of the last ice age. At the same time, they’ll be investigating the modern-day plants of the northeast alpine region, both in the field and in experimental gardens. Finally, researchers will share their results in a podcast showcasing alpine plants and the people who work with them, as well as in a new AI-powered app (presented during training workshops at the Northeast Alpine Stewardship Gatherings) that will help managers and others make informed decisions about how best to steward this vital natural heritage through the coming century. The overall goal of this work is to help scientists, volunteers, and managers understand how better to support not only alpine plants across the northeast, but in other parts of the world where rare or isolated species are faced with climate change and other threats.This project will integrate tools from paleoecology, community ecology, trait ecology, population genomics, and geography to develop an understanding of how alpine plant communities in the northeast assembled and persisted. Focusing on the Adirondacks (NY), the Green (VT) and White (NH) Mountains, and Katahdin (ME), the research team will first characterize the last ~13,000 years of vegetation dynamics at the species level using ancient DNA from alpine sediment cores. To characterize changes in response to historic warming, they will then conduct plant surveys to estimate species turnover over the last century by comparing modern-day flora with historic survey records. The team will then combine data from common garden experiments, microclimate sensor arrays, functional trait analyses, and coalescent modeling from population genomic data to reveal past and contemporary demographic dynamics and clarify the relative roles of microrefugia, phenotypic plasticity, and local adaptation in driving biodiversity turnover across millennial, centennial, and decadal timescales. The study will focus on six focal taxa that represent key alpine plant functional types (graminoids, forbs, and dwarf shrubs). The resulting multi-dimensional biodiversity data will inform predictive models that will be shared with regional managers after being tested against past known biodiversity dynamics. Through this novel, integrative approach, the project aims to increase predictive power in forecasting biodiversity dynamics in fragmented populations in a warming world by quantifying the relative roles of climate refugia, metapopulation processes, phenotypic plasticity, and adaptive capacity in an integrative framework.This proposal is jointly funded by the Biodiversity on a Changing Planet program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.