Collaborative Research: Investigating tree rings as archives for atmospheric Hg concentrations using Hg, carbon isotopes, and comparisons to other proxies

合作研究：使用汞、碳同位素研究树木年轮作为大气汞浓度的档案，并与其他替代指标进行比较

• 批准号: 2152874
• 负责人: Monica Arienzo
• 金额: $ 5.78万
• 依托单位: Nevada System of Higher Education, Desert Research Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2152874&HistoricalAwards=false
• 关键词: Collaborative; Research; Investigating; tree; rings

In addition to recording atmospheric conditions, trees also take up atmospheric pollutants, such as mercury, and store them in the wood they produce each year. Thus, tree rings are a promising archive of historic mercury pollution, however there remains a lot unknown about how trees take up and then store mercury in their rings. This research project aims to address this by studying how tree physiology influences how trees capture mercury from the air. Other archives of mercury (e.g. ice cores) often have high uncertainty in their dating and record mercury deposition. Comparing tree rings and other records will improve understanding of historic mercury pollution. There are very few records of mercury in the environment that are older than a few hundred years. One of the aims of this project is to develop records of up to 2000 years of atmospheric mercury, improving our understanding of natural atmospheric mercury, including how mercury is influenced by volcanic activity, wildfire and past climate changes. The knowledge and data generated in this project will be of immense value to future research projects on mercury pollution related to historic industrial practices and land-use changes, and will assist in our research into the nature and scale of industrial era mercury pollution and provide new insights to those seeking to further reduce atmospheric mercury. New reliable records of pre-industrial atmospheric mercury are also extremely important for current efforts to monitor and assess changes in mercury emissions as part of the United Nations Minamata Convention. Information, insights and approaches developed in this project will be used in exciting education and training opportunities for undergraduate and graduate students, including those from underserved groups, and in hands-on science modules for K-12 educators. Although tree-rings are a promising high-resolution archive for reconstructing past concentrations of atmospheric mercury (Hg) there remain factors that need to be further investigated. This research project aims to improve the utility of tree-rings as an Hg archive by 1) using concurrent stable carbon isotope measurements to better understand how within-tree processes related to stomatal conductance influence the incorporation of Hg into tree rings; 2) comparing concentrations of Hg in tree rings to measurements from small-catchment lake sediment and ice cores to test the fidelity of the Hg signals observed; and 3) develop long-term records of Hg concentrations derived from tree rings to investigate important natural drivers of atmospheric Hg (e.g. volcanic activity, wildfire & climate). Through the unique combination of Hg concentrations and stable carbon isotope measurements, the biotic influences on the incorporation of Hg into tree rings will be better understood. By comparing concentrations of Hg in tree rings to Hg deposition measurements from small-catchment lake sediment and ice cores, the differences and similarities between these two types of records will improve understanding of how Hg is preserved in these different archives, providing important information on post-depositional processes in depositional archives. Finally, a long-term (up to 2000 year) record of Hg concentration from tree rings will improve our understanding of natural variability in atmospheric Hg.This project is jointly funded by the Geobiology and Low-Temperature Geochemistry Program, and the Established Program to Stimulate Competitive Research (EPSCoR).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.

除了记录大气条件外，树木还占用大气污染物（例如汞），并将它们存放在每年生产的木材中。因此，树环是历史悠久的汞污染的有前途的档案，但是关于树木如何占用然后将汞存储在戒指中仍然存在很多尚不清楚。该研究项目旨在通过研究树木生理如何影响树木如何从空气中捕获汞的方法来解决这一问题。其他汞档案（例如冰核）的约会和记录汞沉积通常具有很高的不确定性。比较树环和其他记录将改善对历史汞污染的理解。在环境中，很少有汞的记录超过几百年。该项目的目的之一是开发多达2000年大气汞的记录，以提高我们对自然气氛的理解，包括如何受到火山活动，野火和过去气候变化的影响。该项目中产生的知识和数据将对与历史工业实践和土地利用变化有关的未来研究项目具有巨大的价值，并将帮助我们研究工业时代汞污染的性质和规模，并为寻求进一步减少大气汞的人们提供新的见解。作为联合国Minamata公约的一部分，在当前监测和评估汞排放变化的努力方面，新的可靠记录对于当前的努力和评估汞排放的变化也非常重要。该项目中开发的信息，洞察力和方法将用于激动人心的教育和培训机会，包括本科生和研究生，包括服务欠缺的小组，以及针对K-12教育者的动手科学模块。尽管树木是一个有希望的高分辨率档案，用于重建过去的大气汞（HG），但仍需要进一步研究的因素。该研究项目旨在通过1）使用并发稳定的碳同位素测量来更好地了解与气孔电导相关的树内过程如何影响汞融合到树环中； 2）比较树环中的汞浓度与从小型湖泊沉积物和冰芯的测量，以测试观察到的HG信号的保真度； 3）开发从树环得出的HG浓度的长期记录，以研究大气HG的重要自然驱动因素（例如火山活动，野火和气候）。通过HG浓度和稳定的碳同位素测量的独特组合，将更好地理解对HG掺入树环中的生物影响。通过将树环中的HG浓度与小型湖泊沉积物和冰核的HG沉积测量进行比较，这两种类型的记录之间的差异和相似性将提高人们对这些不同档案中如何保留HG的理解，从而提供有关沉积档案中沉积后过程的重要信息。最后，从树环中获得HG浓度的长期记录将提高我们对大气HG自然可变性的理解。该项目由地球生物学和低温地球化学计划共同资助，并建立了既定的计划，以及刺激竞争性研究（EPSCOR）的既定范围。审查标准。