Collaborative Research: Long-term carbon storage shifts in high-latitude peatlands with paleoclimate change: Linking peatland modeling with paleoecology and paleohydrology

这是一个迭代的数据模型调查古气候和长期的碳积累之间的关系，从阿拉斯加北极泥炭地档案。这一假说认为，气候通过温度和湿度的变化控制泥炭地的碳储存，这些变化与生产和分解过程有关。利用现有的泥炭地核心从两个北极地区从晚冰期到全新世提供了各种气候情景来研究碳封存。例如，该小组假设温暖，干燥的间隔导致泥炭地碳储存下降，而凉爽，潮湿的气候导致碳封存增加。使用新的工具，包括化合物特定的同位素和生物标志物分析，以及现有的传统古气候代理，如花粉，宏化石和brittites，研究人员将产生详细的气候和水文重建，以及高分辨率AMS-14 C测年，碳和体积密度测量将提供从晚冰期到现在的碳积累率，并使团队能够测试他们的碳封存-气候假设使用新开发的泥炭地积累模型。由于高纬度温暖的北极和亚北极泥炭地为气候系统提供了积极和消极的碳反馈，因此重要的是要将古视角添加到我们对震级和时空尺度的理解中。这项研究将结合古生态学/古气候变化的详细分析（通过branite，化合物特异性同位素分析，花粉和宏体化石分析），在高纬度泥炭地在最后一次冰期-间冰期循环中量化不同环境中的碳封存（即，湿与干麝香）。这些古泥炭地的历史将提供长期的碳封存记录，可用于与来自相同沉积物的古气候重建进行比较，以及冰芯，海洋记录和湖泊地层学。新的全新世泥炭地模型将利用独立的古气候数据，以几十年到几千年的时间尺度，以每年的时间步长模拟北方泥炭地的耦合碳和水动态。模型模拟的碳积累记录可以与泥炭地的历史进行比较，并在植物组成，生产力和分解方面进行差异评估。这种迭代模型数据研究将提供长期的经验信息，以评估水文循环在未来湿地碳循环中的作用，以及过去气候和植被在数千年来固碳的重要性。图利克湖的北坡，那里有一个广泛的生态数据库，以及西部梅萨遗址的北极山麓。AMS 14 C年龄以及Pb-210和Cs-137将与C和体积密度一起使用，以确定每个地点的碳积累。通过对硼镁石和同位素/生物标志物的分析，将确定这些地点的水分状况以及由于火山灰沉积而可能发生的水化学变化。特别感兴趣的是气候间隔，如博林Allerod/新仙女木，全新世早期，前北方和8200年的事件，全新世中期，新冰期，小冰期，和过去的50年。这个项目将涉及至少4篇本科生论文和一个博士后。PI在指导本科生和为研究生提供实地和实验室项目建议方面有着良好的记录，她的许多前实习生都在同行评议的期刊上发表了他们的成果。学生将有机会在地方，州和国家层面展示结果。该小组将继续其长期领导的科学计划培训高中学生和教师在美国宇航局/GISS夏季计划的少数民族和哥伦比亚大学？地球与环境科学系的研究生和本科生，以及当地的博物馆和公共项目的推广。他们打算聘请一名K-12教师在拉蒙多尔蒂地球观测站VAST（访问北极/亚北极夏季教师）计划中进行实地和实验室研究，以产生深远的影响。此外，他们的分析可以用于哥伦比亚大学课程的PI教授的湿地和气候变化，陆地古气候，以及在植物生态学和古生态学的研讨会，并在课程的UNH PI教授（生物地球化学和环境建模）。这项工作的结果和结论将对北极气候政策、生态系统管理和教育产生影响。

This is an iterative data-model investigation of the relationship between paleoclimate and long-term carbon accumulation from Alaskan arctic peatland archives. The hypothesis is that climate controls carbon storage in peatlands through shifts in temperature and moisture related processes of production and decomposition. Use of an existing set of peatland cores from two arctic regions from the late-glacial to the Holocene offers a variety of climate scenarios to examine carbon sequestration. For example, the group hypothesizes that warm, dry intervals result in peatland carbon storage decline, while cool, wet climates result in increased carbon sequestration. Using new tools, including compound-specific isotope and biomarker analysis, and existing traditional paleoclimate proxies such as pollen, macrofossils, and bryophytes, the researchers will produce detailed climate and hydrological reconstructions, and high resolution AMS-14C dating, C and bulk density measurements will provide carbon accumulation rates from the late-glacial to the present and enable the team to test their carbon sequestration-climate hypotheses using a newly-developed mechanistic peatland accumulation model. As high latitudes warm and arctic and subarctic peatlands provide positive and negative carbon feedbacks to the climate system, it is important to add the paleo-perspective to our understanding of magnitude and temporal and spatial scales. This research will couple detailed analysis of changes in paleoecology/paleoclimate (through bryophyte, compound-specific isotope analysis, pollen, and macrofossil analysis) in high latitude peatlands over the last glacial-interglacial cycle with quantification of carbon sequestration in different environments (i.e., wet vs. drier muskegs). These paleo-peatland histories will provide long-term carbon sequestration records, which can be used for comparisons with paleoclimate reconstructions from the same sediments, as well as ice cores, marine records, and lake stratigraphy. The independent paleoclimate data will be utilized by the new Holocene Peatland Model to simulate coupled carbon and water dynamics of northern peatlands at an annual time step over time scales of decades to millennia. The model-simulated carbon accumulation record can be then compared with the peatland histories, and differences evaluated in terms of plant composition, productivity, and decomposition. This iterative model-data research will provide long-term empirical information necessary to evaluate the role of the hydrological cycle in future wetland carbon cycling, and the past importance of climate and vegetation in sequestering carbon over millennia.The selected sites for new sampling include peatlands of Alaska?s North Slope at Toolik Lake where an extensive ecological database exists as well as the arctic foothills of the western Mesa site. AMS 14C ages, as well as Pb-210 and Cs-137, will be used in conjunction with C and bulk density to determine carbon accumulation for each site. Analysis of bryophyte and isotopes/biomarkers will provide defined moisture regimes as well as possible water chemistry changes due to volcanic ash deposition in these sites. Of particular interest are climatic intervals such as the Bolling-Allerod/Younger Dryas, the early Holocene, the Preboreal and 8200-yr events, mid-Holocene, the Neoglacial, Little Ice Age, and the last 50 years. This project will involve at least 4 undergraduate theses and one postdoc. The PI has a well-documented record of mentoring undergraduates and advising graduate students in field and lab-based programs, with many of her former advisees publishing their results in peer-reviewed journals. Students will have an opportunity to present results at the local, state, and national levels. The group will continue its long leadership in science programs training high school students and teachers at NASA/GISS summer program for minorities and Columbia University?s Department of Earth and Environmental Science graduate and undergraduate students, as well as local outreach to museums and public programs. They intend to engage a K-12 teacher in their field and lab research in the Lamont Doherty Earth Observatory VAST (Visiting Arctic/subarctic Summer Teacher) program for far-ranging impact. Additionally, their analyses can be utilized for the Columbia University courses the PI teaches on Wetlands and Climate Change, Terrestrial Paleoclimate, as well as seminars in Plant Ecology and Paleoecology, and in courses the UNH PI teaches (Biogeochemistry and Environmental Modeling). The results and conclusions of this work will have implications for arctic climate policy, ecosystem management, and education.