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变暖导致冰冻圈(冰雪)和陆地生态系统发生广泛变化。这些最近的变化以及更长期的气候和生态系统历史将通过泥炭沉积来破译。泥炭堆积可以用来评估冰川消退的速度，并提供对南极半岛新消融冰川景观的生态过程的洞察。该项目以数据为基础，表明最近的生态系统变化与南极半岛西部过去的气候有关，并为评估最近冰川变化的程度和速度提供了一个时间表。这项研究将创造沿海低海拔陆地地区的气候记录，这将完善最近过去(过去12,000年)高达6摄氏度的主要气候变化。对近期冰川历史的一种新的陆地记录将提供对南极半岛西部气候和海冰动态观测变化的洞察，并使之能够与在沉积物中捕获的近海气候记录进行比较。该项目的观察和发现将传播到当地学校和科学中心。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。该研究提出了一项新的系统调查，利用保存在全新世晚期泥炭沉积中的替代记录重建南极半岛西部沿海低海拔地区的生态系统和气候变化。将收集和分析苔藓和泥炭样本，以生成关于晚全新世气候变化和生态系统动态的全面数据集。其目标是记录和了解西部AP地区在全新世晚期的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，过去的温暖促进了生态系统和冰冻圈的戏剧性反应。该项目的一个主要成果是，利用泥炭生物和地球化学替代物的多种证据，有力地重建了沿海低海拔陆地地区晚全新世的气候变化，这些证据将用于与从AP地区的海洋沉积物和冰芯获得的气候记录进行比较。这些数据将被用来测试过去较温暖气候中与新的泥炭形成生态系统(如南极毛草沼泽)有关的几个想法，以及对生态系统建立和迁移的气候控制，以帮助评估小冰期冷却和冰冻圈反应的性质。泥炭岩芯的年代学将通过对大型化石的放射性碳测年和贝叶斯模型来建立。生态系统和气候变化的高分辨率时间序列将有助于将观察到的最近变化置于长期背景下，以跨越不同时间尺度的气候动态。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.