Linking hydrology with biogeochemistry using stable isotopes to understand the consequences of ecosystem disturbance

使用稳定同位素将水文学与生物地球化学联系起来，以了解生态系统干扰的后果

• 批准号: 355866-2008
• 负责人: Mitchell, Carl
• 金额: $ 1.09万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=402741
• 关键词: Linking; hydrology; biogeochemistry; using; stable

Understanding how pollutants move through the environment and are transformed within it is important to developing plans for mitigating pollutant effects. Some pollutants, including heavy metals, strongly bind to soil and other solids in the environment. Despite this affinity, these pollutants continue to move into aquatic ecosystems when soils are flushed by rainstorms or melting snow. Linking the movement of water and chemical reactions in the environment together at appropriate spatial and temporal scales is difficult, but critical to providing the process information necessary to deal with changing levels of pollution and possible alterations to the environment (climate change, logging). Recent advances in techniques involving enriched stable (non-radioactive) isotopes should provide a means for linking these processes. The pollutant to be studied in this research program is mercury, a toxic metal. Mercury is particularly dangerous because it can undergo biogeochemical transformations in the environment that form methylmercury, a potent neurotoxin that accumulates in fish and wildlife. The consumption of fish is the primary pathway for human exposure. Through a number of controlled laboratory and field experiments using stable isotopes, this research will first investigate and develop a model of how mercury moves between ecosystem compartments such as forests and wetlands. It will then investigate the spatial and temporal variability of this movement and its effects on the production of methylmercury. This information will be used to directly test how logging affects the movement and transformation of mercury in watersheds. Together, this knowledge will lead to more predictive possibilities from models, an improved understanding of how land-use changes affect mercury cycling, and an opportunity to develop effective strategies for preventing further methylmercury pollution in watersheds.

了解污染物如何在环境中移动并在环境中转化对于制定减轻污染物影响的计划非常重要。 包括重金属在内的一些污染物与环境中的土壤和其他固体紧密结合。 尽管存在这种亲和力，但当土壤被暴雨或融雪冲刷时，这些污染物仍会继续进入水生生态系统。 在适当的空间和时间尺度上将环境中水的运动和化学反应联系在一起很困难，但对于提供处理不断变化的污染水平和可能的环境变化（气候变化、伐木）所需的过程信息至关重要。 涉及浓缩稳定（非放射性）同位素的技术的最新进展应该提供一种连接这些过程的方法。 本研究计划要研究的污染物是汞，一种有毒金属。 汞特别危险，因为它可以在环境中发生生物地球化学转变，形成甲基汞，这是一种在鱼类和野生动物体内积聚的强效神经毒素。 食用鱼类是人类接触该物质的主要途径。 通过使用稳定同位素进行的一系列受控实验室和现场实验，这项研究将首先调查并开发汞如何在森林和湿地等生态系统分区之间移动的模型。 然后它将研究这种运动的空间和时间变化及其对甲基汞产生的影响。 该信息将用于直接测试伐木如何影响流域中汞的移动和转化。 总之，这些知识将带来更多模型预测的可能性，更好地了解土地利用变化如何影响汞循环，并有机会制定有效的战略来防止流域进一步的甲基汞污染。