Trace element patterns in uncontaminated soils: The imprint of trees.

未受污染土壤中的微量元素模式：树木的印记。

• 批准号: RGPIN-2018-04539
• 负责人: Courchesne, François
• 金额: $ 4.37万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754702
• 关键词: Trace; element; patterns; uncontaminated; soils

The research proposal is a central component of our long-term program on the biogeochemistry of TE in terrestrial ecosystems. The proposal focuses on the development of trace element (TE) patterns in soils of uncontaminated forest areas. Indeed, TE not only accumulate in soils of polluted areas but they also form patterns, with localized hot spots, in soils of uncontaminated areas. Processes responsible for pattern development have yet to be established but the uplift of TE by trees is among the main mechanisms invoked. The TE arsenic (As), cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) are analyzed because they are common contaminants in soils of Canada and because they are potentially toxic to the biota and to humans. The trees investigated grow in deciduous forest stands and include Sugar maple, Yellow birch, American beech, and Trembling aspens. This program is the very first to attempt at bridging this significant knowledge gap in the field of terrestrial biogeochemistry.The working hypothesis driving the proposal is: The spatial distribution of individual trees from distinct species within a given forest stand has a direct impact on the development of spatial TE patterns in the surface horizons of the underlying soils. The four interconnected questions asked to test the hypothesis are: 1) What are the characteristics of soil TE patterns forming in the surface horizons of uncontaminated forest soils? 2) What are the biogeochemical processes involved in the development of soil TE patterns? 3) What is the timescale required for the establishment of the properties and metrics characterizing soil TE patterns? and 4) What is the potential for generalization of the scientific knowledge generated by the proposal?Our scientific approach combines original field experiments in forested ecosystems, state-of-the-art analytical techniques and innovative multivariate statistical analyses to gather high-quality data on the TE chemistry of soil patterns in uncontaminated forested ecosystems. The field work will be conducted in range of watersheds and forest stands that are representative of the terrestrial environments found in southeastern Canada and northeastern USA. The broad range of environmental conditions studied will allow to evaluate the impact of a series of soil properties and of tree species on TE pattern development and will insure the assessment of the generality of findings generate by the proposal.Advances in knowledge in the area of TE research are needed by our society to anticipate the response of terrestrial ecosystems to environmental changes, such as shifts in climatic conditions, in atmospheric TE deposition or in dominant tree species, to further the development of efficient green technologies for the remediation of TE-contaminated soils and to manage the flow of TE along the food-chain in a context of sustainable food production.

该研究计划是我们陆地生态系统TE生物地球化学长期计划的核心组成部分。该建议侧重于未污染森林地区土壤中微量元素（TE）模式的发展。事实上，TE不仅在污染地区的土壤中积累，而且在未污染地区的土壤中也形成了具有局部热点的模式。负责模式发展的过程尚未确定，但树木对TE的提升是所调用的主要机制之一。对TE砷（As）、镉（Cd）、铜（Cu）、镍（Ni）、铅（Pb）和锌（Zn）进行分析，因为它们是加拿大土壤中常见的污染物，而且对生物群和人类都有潜在的毒性。被调查的树木生长在落叶林中，包括糖枫、黄桦树、美洲山毛榉和白杨。这个项目是第一个试图在陆地生物地球化学领域弥合这一重大知识鸿沟的项目。推动该提议的工作假设是：特定林分内不同物种的单株树木的空间分布直接影响下伏土壤表层空间TE模式的发展。检验这一假设的四个相互关联的问题是：1)未受污染的森林土壤表层形成的土壤TE模式的特征是什么？2)哪些生物地球化学过程参与了土壤TE模式的发展？3)建立表征土壤TE模式的属性和度量所需的时间尺度是什么？4)该提案产生的科学知识的推广潜力如何？我们的科学方法结合了原始的森林生态系统现场实验，最先进的分析技术和创新的多元统计分析，以收集未受污染的森林生态系统土壤模式TE化学的高质量数据。实地工作将在加拿大东南部和美国东北部具有陆地环境代表性的流域和林分范围内进行。研究范围广泛的环境条件将有助于评估一系列土壤特性和树种对TE模式发展的影响，并将确保评估建议产生的调查结果的普遍性。我们的社会需要在TE研究领域的知识进步来预测陆地生态系统对环境变化的反应，例如气候条件的变化，大气TE沉积或优势树种的变化，以进一步开发有效的绿色技术来修复TE污染的土壤，并在可持续粮食生产的背景下管理TE沿着食物链的流动。