Collaborative Research: Reconstructing Late Holocene Ecosystem and Climate Shifts from Peat Records in the Western Antarctic Peninsula

20世纪后期南极半岛西部的变暖导致了冰冻圈（冰雪）和陆地生态系统的广泛变化。这些近期的变化以及长期的气候和生态系统历史将通过泥炭沉积物来破译。泥炭积累可以用来评估冰川退缩的速度，并为南极半岛新冰川消融景观的生态过程提供见解。该项目建立在表明近期生态系统转变与南极半岛西部过去气候有关的数据基础上，并提供了一个评估近期冰川变化程度和速度的时间表。这项研究将产生沿海低海拔陆地地区的气候记录，这将完善最近（过去12000年）高达6摄氏度的主要气候变化。最近冰期历史的一种新的陆地记录将提供对南极半岛西部观测到的气候和海冰动态变化的深入了解，并允许与沉积物中捕获的近海气候记录进行比较。这个项目的观察和发现将被传播到当地的学校和科学中心。该项目为博士后科学家以及研究生和本科生提供培训和职业发展。利用全新世晚期泥炭沉积的代用记录，为南极半岛西部沿海低海拔地区的生态系统和气候变化重建提供了一种新的系统调查方法。苔藓和泥炭样品将被收集和分析，以产生一个全面的数据集晚全新世的气候变化和生态系统动态。目的是记录和理解全新世晚期AP西部景观和陆地生态系统的变化。可验证的假设是，沿海地区经历了比冰芯记录所证明的更大的气候变化，过去的变暖促进了戏剧性的生态系统和冰冻圈反应。该项目的一个主要成果是利用泥炭基生物和地球化学代用物的多种证据，对沿海低海拔陆域的晚全新世气候变化进行强有力的重建，这些证据将用于与来自AP地区海洋沉积物和冰芯的气候记录进行比较。这些数据将用于测试与过去温暖气候下的新型泥炭形成生态系统（如南极毛草沼泽）有关的几个想法，以及气候对生态系统建立和迁移的控制，以帮助评估小冰期冷却和冰冻圈响应的性质。泥炭岩心的年代将通过大型化石的放射性碳定年和贝叶斯模型确定。高分辨率的生态系统和气候变化时间序列将有助于将观测到的近期变化置于长期背景下，以跨越不同时间尺度的气候动力学。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。

Warming on the western Antarctic Peninsula in the later 20th century has caused widespread changes in the cryosphere (ice and snow) and terrestrial ecosystems. These recent changes along with longer-term climate and ecosystem histories will be deciphered using peat deposits. Peat accumulation can be used to assess the rate of glacial retreat and provide insight into ecological processes on newly deglaciated landscapes in the Antarctic Peninsula. This project builds on data suggesting recent ecosystem transformations that are linked to past climate of the western Antarctic Peninsula and provide a timeline to assess the extent and rate of recent glacial change. The study will produce a climate record for the coastal low-elevation terrestrial region, which will refine the major climate shifts of up to 6 degrees C in the recent past (last 12,000 years). A novel terrestrial record of the recent glacial history will provide insight into observed changes in climate and sea-ice dynamics in the western Antarctic Peninsula and allow for comparison with off-shore climate records captured in sediments. Observations and discoveries from this project will be disseminated to local schools and science centers. The project provides training and career development for a postdoctoral scientist as well as graduate and undergraduate students.The research presents a new systematic survey to reconstruct ecosystem and climate change for the coastal low-elevation areas on the western Antarctic Peninsula (AP) using proxy records preserved in late Holocene peat deposits. Moss and peat samples will be collected and analyzed to generate a comprehensive data set of late-Holocene climate change and ecosystem dynamics. The goal is to document and understand the transformations of landscape and terrestrial ecosystems on the western AP during the late Holocene. The testable hypothesis is that coastal regions have experienced greater climate variability than evidenced in ice-core records and that past warmth has facilitated dramatic ecosystem and cryosphere response. A primary product of the project is a robust reconstruction of late Holocene climate changes for coastal low-elevation terrestrial areas using multiple lines of evidence from peat-based biological and geochemical proxies, which will be used to compare with climate records derived from marine sediments and ice cores from the AP region. These data will be used to test several ideas related to novel peat-forming ecosystems (such as Antarctic hairgrass bogs) in past warmer climates and climate controls over ecosystem establishment and migration to help assess the nature of the Little Ice Age cooling and cryosphere response. The chronology of peat cores will be established by radiocarbon dating of macrofossils and Bayesian modeling. The high-resolution time series of ecosystem and climate changes will help put the observed recent changes into a long-term context to bridge climate dynamics over different time scales.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.