Collaborative Research: How Mountains Maintain Biodiversity: A Multidisciplinary Characterization of a Pleistocene Refugium in the Interior Pacific Northwest

了解物种对历史气候变化的反应，有助于预测人类介导的全球变化对生物生态系统的未来影响。山地地形包含了广泛的栖息地和多种物种，这些栖息地和物种是由上一个冰河时代以来的重大气候变化历史所塑造的。这些变化包括植被的迅速和重大变化（即从冻土带向森林的转变）。在气候不适宜的时期，山区也被认为是生物多样性的避难所。该项目将描绘一个冰河时期的避难所，该避难所可能在爱达荷州北部陡峭的地形上庇护着各种各样的动植物物种，从而阐明山区地形如何在重大气候变化中缓冲种群。该项目以北部针叶林的两种主要树种（西部红杉和山铁杉）为研究对象，将整合三种方法，利用它们的互补优势来推断过去的种群规模和位置。首先，先进的dna测序方法将揭示物种迁移路径的遗传足迹，并测试避难所的存在。其次，新的花粉古生态记录和大型化石将揭示近5万年来最冷时期的区域植物物种组成和气候。第三，对整个复杂山区景观的历史气候模拟将与每个物种的生理耐受性信息（例如，抗寒性）相结合，以揭示该地区最可能的避难所位置。该项目的跨学科方法为培养下一代生物地理学家提供了一个机会，他们将需要这些传统上不同的技能，包括遗传学、古生物学和景观建模，以预测未来气候变化的生态影响。研究生将在遗传学、古生态学和景观生态学实验室之间轮换，以实现这一培养目标。此外，将为高中教师举办课程研讨会，并用于开发实践活动的课程。

Understanding the responses of species to historical shifts in climate informs predictions of the future impacts of human-mediated global changes on biological ecosystems. Mountainous terrain contains a wide range of habitats and diverse species, which have been shaped by a history of major climate changes since the last ice age. These changes include rapid and major changes in vegetation (i.e., shifts from tundra to forest). Mountainous regions are also thought to harbor biodiversity in refugia during otherwise inhospitable climate periods. This project will characterize an ice-age refugium that may have harbored a wide diversity of plant and animal species in steep terrain in northern Idaho, and thus illuminate how mountainous terrain may buffer populations through major climate changes. Focusing on two, dominant tree species in northern coniferous forests (western redcedar and mountain hemlock), this project will integrate three methodological approaches to leverage their complementary strengths in inferring past population sizes and locations. First, cutting-edge DNA-sequencing methods will reveal the genetic footprints of species' migration pathways and test for the existence of refugia. Second, new paleoecological records of pollen and macrofossils will reveal the regional plant species composition and climate during the coldest periods in the past 50,000 years. Third, simulations of historical climate across the complex mountainous landscape will be combined with information on the physiological tolerances of each species (e.g., cold hardiness), to reveal the most likely locations of refugia within this region. The interdisciplinary approach of this project provides an opportunity to train the next generation of biogeographers, who will need these traditionally distinct skill sets in genetics, paleontology, and landscape modeling to forecast ecological impacts of future climate change. Graduate students will rotate among genetics, paleoecology and landscape ecology labs to achieve this training goal. In addition, a curriculum workshop will be conducted for high school teachers, and used to develop lessons for hands-on activities.