Collaborative Research: Plant phenology, local adaptation, and growing season length in the changing Arctic tundra

在北极，植物在6月冬雪融化后开始生长。8月份气温变冷时，它们就停止生长。北极的生长季节向北较短，向南较长。这导致它们的生长时间在不同的普通植物种群之间有所不同。由于气候变化，北极比更靠南的地区变暖得更快，生长季节也越来越长。由于基因的原因，一些植物可能无法适应较长的生长季节。相比之下，其他人可能拥有允许他们改变的基因。我们在北极发现了这两种。这项研究将研究光线、温度和基因如何共同决定北极植物如何应对生长季节的变化。对于一些植物，我们会调整它们接收到的光量来观察它们的反应。我们将研究这些植物是否有基因，使它们在生长季节变化时保持活跃。这种方法将有助于了解这些植物是否会在未来变暖的北极生长。为了帮助在阿拉斯加工作的科学家，宾夕法尼亚州的高中生将在实验室里种植北极植物，观察它们对光线变化的反应。来自德克萨斯大学埃尔帕索分校的大学生将帮助在阿拉斯加进行实地考察。植物物候，即叶片形成、死亡和开花的时间，是受气候变化影响最大的特征之一。在北极，植物物候的变化可以在多个层面上改变生态系统的功能。本课题组先前的研究发现，北方和南方的棉草种群在生长季节长度上存在显著差异。这一发现表明该物种的物候受遗传制约。本项目将研究本地适应对柞棉草及其两种竞争对手矮桦和茶叶柳物候学的影响。该假说认为，温度、光线和基因在不同的组合下导致了北极物候学的差异。这些控制的强度在不同环境中的种群之间会有所不同。田间和生长室实验将确定温度、光和遗传对植物物候的作用。我们将在叶片和生态系统尺度上监测植物，以了解物候和生长季节长度如何影响植物功能和生态系统响应。多种方法的结合将为北极植物对气候变化的反应提供一个统一的方法。这个项目将对北极科学产生更广泛的影响，因为它建立在一个强大的传统上，让本科生参与北极实地研究。该项目将从一所拥有许多第一代学生的小型大学和一家领先的西班牙裔服务机构招募助理。它还将让威尔克斯-巴雷的高中生参与物候学的实验室研究。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In the Arctic, plants begin their growth after winter snow melts in June. They stop growing when cold temperatures return in August. The growing season in the Arctic is shorter further north and longer towards the south. This causes the timing of their growth to vary between different populations of common plants. Because of climate change, the Arctic is getting warmer faster than areas that are further south, and the growing season is getting longer. Some plants may not adjust to the longer growing season because of their genes. In contrast, others may have genes that permit them to change. We find both kinds in the Arctic. This research will examine how light, temperature, and genetics work together to determine how arctic plants respond to changes in the growing season. For some plants, we will adjust the amount of light they receive to see how the plants respond. We will study if the plants have genes that allow them to stay active if the growing season changes. This approach will help to understand whether the plants will grow in a future warmer Arctic. To help the scientists working in Alaska, high school students in Pennsylvania will grow arctic plants in a laboratory to see how they respond to changes in light. College students from the University of Texas at El Paso will help with fieldwork in Alaska.Plant phenology, or the timing of leaf initiation, leaf death, and flowering, is one trait most affected by climate change. In the Arctic, changes in plant phenology can alter how ecosystems function at multiple levels. Previous research by our group identified a significant difference in growing season length between northern and southern populations of tussock cottongrass. This finding suggests that the phenology of this species is under genetic constraint. The present project will investigate the effect of local adaptation on the phenology of tussock cottongrass and two of its competitors, the dwarf birch and tealeaf willow. The hypothesis is that temperature, light, and genetics, in different combinations, are responsible for differences in phenology in the Arctic. The strength of these controls will vary between populations that are found in different environments. Field and growth chamber experiments will determine the role of temperature, light, and genetics on plant phenology. We will monitor plants at the leaf and ecosystem scales to understand how phenology and growing season length affect plant function and ecosystem responses. A combination of methods will provide a unified approach to plant response to climate change in the Arctic. This project will have broader impacts on arctic science by building on a strong tradition that involves undergraduates in arctic field research. The project will recruit assistants from a small university with many first-generation students and from a leading Hispanic Serving Institution. It will also involve high school students from Wilkes-Barre in laboratory studies of phenology.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.