Collaborative Research: Ecosystem Response to a Warming Arctic: Deciphering the Past to Inform The Future.

北极目前的变暖速度是全球平均速度的两倍，预计这将导致植物范围向北移动。木本植被的增加将减少表面对光和热的反射（反照率），并增加大气中的水蒸气，这是一种正反馈，目前气候模式中很少包括这种正反馈。在加拿大东部北极地区（ECA）跨越当前间冰期和较温暖的前间冰期湖泊的分层沉积物中，保存了沉积的古代DNA （sedaDNA）和有机分子，可用于重建过去的生态系统及其对温度和水文气候的依赖。通过将这些沉积物的数据与现代植被研究和气候监测相结合，将建立一个基于经验的生态系统-气候模型，以预测在一系列气候轨迹情景下北极生态系统到2100年的可能演变。这将是第一次将基于sedadna的植被记录与湖泊沉积物中基于生物标志物的气候记录结合起来，其中包含了更温暖的北极记录。很少有生态系统的研究薄土壤上的结晶地形的ECA。在强气候梯度条件下，对目标湖泊的植物区系研究和植被环境分析建立了植物组合与夏季温度之间的当前关系，并确定了sedaDNA与附近植物群落之间的关系。土壤、空气和湖水的温度记录器以及现代土壤和湖泊表层沉积物的DNA和生物标记物分析将加强对有前途的新分子代用物的理解，并促进区域训练集的发展。该项目汇集了北极植物生态学、古气候、sedaDNA和有机地球化学领域的专家和最先进的设施，对高纬度地区气候和生物地理之间复杂的相互作用产生了变革性的新见解，并将对生态系统对整个非洲经委会预期的未来变暖的潜在反应产生强有力的看法。项目团队致力于通过与加拿大北极地区以及国内的当地社区的联系，与更广泛的公众分享研究成果。该小组将在实地考察期间与因纽特人的向导和助手密切合作，其中大部分工作在传统的狩猎和渔场附近，并将通过在加拿大公园办公室的展览与附近的因纽特人社区分享结果。与努纳武特研究所及其附属北极学院的牢固合作关系已经发展了几十年，这种伙伴关系将通过与北极学院环境技术项目的学生和工作人员合作建立一个互动湖泊监测项目来扩大。在科罗拉多州的博尔德市，一项由奖学金支持的暑期实地考察和实验课程将以古生态和古气候观点为基础，面向代表性不足的高中生。该项目将帮助启动两名早期职业科学家，一名女性和一名拉丁裔，以及一名职业科学家和两名博士后，其中两名是女性，以及两名新的研究生。实验室部分将支持几名研究生和本科生助理，他们将获得宝贵的研究经验，并有机会根据他们的研究活动完成论文。

The Arctic is currently warming twice as fast as the global average and this is expected to result in a northward shift in plant ranges. An increase in woody vegetation would reduce surface reflection of light and heat (albedo), and increase atmospheric water vapor, a positive feedback that is currently poorly included in climate models. In the Eastern Canadian Arctic (ECA) stratified sediment in lakes spanning the current interglacial and the warmer previous interglacial, preserve sedimentary ancient DNA (sedaDNA) and organic molecules that can be used for reconstruction of past ecosystems and their dependence on temperature and hydroclimate. By combining data from these sediments with modern vegetation studies and climate monitoring, an empirically based ecosystem-climate model will be developed to predict the likely evolution of Arctic ecosystems by 2100 under a range of climate trajectory scenarios. This will be the first integration of sedaDNA-based vegetation records with biomarker-based climate records in lake sediment containing records of a much warmer Arctic. There are few ecosystem studies for the thin soils on crystalline terrain of the ECA. Floristic studies and vegetation-environment analyses around targeted lakes across a strong climate gradient establish the current relation between plant assemblages and summer temperature and define the relation between sedaDNA and nearby plant communities. Temperature loggers in soils, air, and lake- water, and analyzes of DNA and biomarkers in modern soils and lake surface sediment will enhance understanding of promising new molecular proxies and facilitate the development of regional training sets. The project brings together experts and state-of- the-art facilities in Arctic plant ecology, Paleoclimate, sedaDNA, and Organic Geochemistry to derive transformative new insight into the complex interplay between climate and biogeography at high latitudes, and will lead to a robust perspective on the potential response of ecosystems to anticipated future warming across the ECA. The project team is committed to sharing research results with the broader public through outreach among local communities in the Canadian Arctic as well as at home. The team will work closely with Inuit guides and assistants during fieldwork, much of which is near traditional hunting and fishing lands, and will share results with nearby Inuit communities through displays at Parks Canada offices. A strong partnership with Nunavut Research Institute and its affiliated Arctic College has been developed over several decades, and this partnership will be expanded by establishing an interactive lake-monitoring program in collaboration with the Environment Technology Program students and staff of Arctic College. In Boulder, Colorado, a scholarship-supported summer field and lab course for underrepresented high school students will be developed based on paleoecological and paleoclimatic perspectives on climate change. This project will help launch two early-career scientists, one female and one Latino, as well as a career scientist and two postdocs, two of whom are female, and two new graduate students. The laboratory component will support several graduate and undergraduate assistants, who will gain valuable research experience and have the opportunity to complete theses based on their research activities.