Collaborative Research: LTREB Renewal: Feedbacks between evolution and demography in severely fragmented prairie populations of the purple coneflower, Echinacea angustifolia

该项目继续对紫锥花紫锥菊的自然选择进行长期研究。19世纪初，大草原覆盖了北美的大片地区。从那时起，大约99%的塔尔格拉斯草原被摧毁。保留下来的小片孤立的草原蕴藏着巨大的生物多样性，但在这些残存的草原上，当地植物的灭绝率高得惊人。这个项目正在推动对为什么一些种群灭绝而另一些种群持续存在的科学理解。这个项目建立在对这些生态和遗传过程以及它们之间影响草原植物物种模式的反馈的长期调查的基础上。紫色的圆锥花是草原植物的典型代表，它的寿命很长，通常是几十年，而且在其他方面也是如此。这项研究是第一次衡量人口适应能力的研究。除了提高科学知识和向科学家和土地管理员传播信息外，该项目还为不同的参与者提供研究经验和培训，培训水平适合他们的兴趣和职业阶段：明尼苏达州和芝加哥植物园的高中、大学和研究生、教师和公民科学家。该项目使用正式的数量遗传方法和常见的花园实验设计来量化适合度、种群分化和近亲繁殖衰退的加性遗传差异。研究人员将使用ASTER统计模型来估计2003年种植的个体达尔文适合度的遗传变异量，其中许多个体在2015年首次开花。其他实验将估计兄弟姐妹之间交配导致的平均健康状况的下降。连同1996年开始的剩余人口人口普查，这些研究将对人口增长率和进化拯救的潜力进行全面评估。这项研究的一个关键优势是，实验是在现实的栖息地进行的，包括圆锥花与其传粉者和草食动物的相互作用。核心数据集包括连续的个人健康记录，包括明尼苏达州10个试验田和27个天然草原残留地上超过17,000株植物的年度存活和繁殖。这些数据集，到项目结束时将延长到30年，为了解长期生存物种的进化和生态过程的相互作用提供了一个难得的窗口。这一奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project continues a long-term study of natural selection in the purple coneflower, Echinacea angustifolia. At the beginning of the 1800s, prairie covered a great swath of North America. Since then, about 99% of the tallgrass prairie has been destroyed. The small, isolated patches of prairie that remain harbor great biodiversity, yet rates of local plant extinctions are alarmingly high in these remnant prairies. This project is advancing scientific understanding of why some populations go extinct and others persist. This project builds on a long-term investigation of these ecological and genetic processes and feedbacks between them affecting a model prairie plant species. The purple coneflower typifies prairie plants in its long lifespan, often decades, and in other attributes. This study is the first of its kind to measure the capacity of a population to adapt. In addition to advancing scientific knowledge and disseminating information to scientists and land stewards, this project provides research experience and training to diverse participants at a level appropriate for their interests and career stage: high school, college, and graduate students, teachers, and citizen scientists in both Minnesota and at the Chicago Botanic Garden. The project uses formal quantitative genetic approaches and common garden experimental designs to quantify additive genetic variance for fitness, population differentiation, and inbreeding depression. Researchers will use aster statistical models to estimate the amount of genetic variation in Darwinian fitness of individuals planted in 2003, many of which flowered for the first time in 2015. Other experiments will estimate the reduction in mean fitness due to mating between siblings. Together with demographic censuses of remnant populations, started in 1996, these studies will yield comprehensive assessments of population growth rates and the potential for evolutionary rescue. A key strength of the research is that experiments are conducted in a realistic habitat, including interactions of the coneflower with its pollinators and herbivores. The core datasets comprise continuous individual fitness records, including annual survival and reproduction of over 17,000 plants in 10 experimental plots and across 27 natural prairie remnants in Minnesota. These datasets, which will extend up to 30 years by the end of the project, offer a rare window into the interplay of evolutionary and ecological processes of a long-lived species.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.