Understanding the Effects of Climate Change on Carbon Fate in Headwater Lakes

了解气候变化对源头湖泊碳命运的影响

• 批准号: RGPIN-2018-06389
• 负责人: Venkiteswaran, Jason
• 金额: $ 2.19万
• 依托单位: Wilfrid Laurier University
• 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=754919
• 关键词: Understanding; Effects; Climate; Change; Carbon

The millions of lakes in Canada are essential to our identity. We regard our freshwater as our most important natural resource. To protect this resource, we need to better understand how lakes function and how catchments drive the fate of carbon (essential to all life, is a greenhouse gas as carbon dioxide and methane, and provides colour to water) in lakes in order to make predictions about how climate change will affect our lakes. The forested landscapes around lakes are critical to water supplies since they provide the majority of drinking water in Canada. A key factor to safe drinking water supplies is managing dissolved organic carbon (the substances that give natural water their colour) in lakes in order to make it treatable without elevated levels disinfection by-products. The effects of climate change on the export of water and carbon from catchments to headwater lakes and the fate of carbon in those lakes is poorly understood.Small lakes are good model ecosystems because they are large enough to contain a full food web, from microbes to fish, come in a variety of sizes and can have a wide range of influences from their catchments. Small lakes are also very good sentinels of change. The Experimental Lakes Area and Dorset Environmental Science Centre offer a rare opportunity to study the role catchments play in driving colour, risk of anoxia, treatability of drinking water, and the fate of carbon in lakes across a climatic gradient. Further, combining their respective decades of research and monitoring with novel analyses provides a unique and exciting approach. There is clear evidence that lakes are changing due to climate change, for example, longer periods of summer stratification allow bottom waters to become anoxic more often and seasonal changes in catchment loading of carbon and nutrients to lakes affects their fate.To date, little work has combined catchment characteristics (such as landcover type, slope, shoreline shape factor and catchment to lake ratio) with dissolved organic carbon quality (such as different types of fluorescence, size fractionation and disinfection by-product formation) to understand how the fates of different types of organic carbon in headwater lakes. The proposed research will make the first big steps in this direction. Outcomes of this research will be used to identify types of lakes that are better suited to drinking water provision. This is critically important for northern communities that have faced long-term problems with safe drinking water. Ultimately, the development of models to predict climate change effects on the fate of carbon in lakes are needed in order to protect the health of these lakes and the services the provide us.

加拿大的数百万个湖泊对我们的身份至关重要。我们认为淡水是我们最重要的自然资源。为了保护这一资源，我们需要更好地了解湖泊的功能以及集水区如何驱动湖泊中碳的命运（对所有生命至关重要，是二氧化碳和甲烷的温室气体，并为水提供颜色），以便预测气候变化将如何影响我们的湖泊。湖泊周围的森林景观对供水至关重要，因为它们提供了加拿大大部分的饮用水。安全饮用水供应的一个关键因素是管理湖泊中的溶解有机碳（使天然水呈现颜色的物质），以便使其可以处理而不会产生高水平的消毒副产品。气候变化对水和碳从集水区输出到源头湖泊的影响以及这些湖泊中碳的命运知之甚少。小型湖泊是很好的生态系统模型，因为它们足够大，可以容纳从微生物到鱼类的完整食物网，大小不等，并且可以受到集水区的广泛影响。小湖泊也是变化的好哨兵。实验湖区和多塞特环境科学中心提供了一个难得的机会，研究集水区在驾驶颜色，缺氧风险，饮用水可处理性以及气候梯度湖泊中碳的命运中所起的作用。此外，将他们各自数十年的研究和监测与新的分析相结合，提供了一种独特而令人兴奋的方法。有明确的证据表明，湖泊正在因气候变化而发生变化，例如，夏季分层时间较长，使底部沃茨更经常地变得缺氧，湖泊中碳和营养物集水负荷的季节性变化影响了湖泊的命运。（如土地覆被类型、坡度、海岸线形状因子和集水区与湖泊的比例）与溶解有机碳质量（如不同类型的荧光，尺寸分级和消毒副产品的形成），以了解不同类型的有机碳在源头湖泊中的命运。拟议中的研究将朝着这个方向迈出第一大步。这项研究的结果将用于确定更适合饮用水供应的湖泊类型。这对于长期面临安全饮用水问题的北方社区至关重要。最终，需要开发模型来预测气候变化对湖泊中碳命运的影响，以保护这些湖泊的健康及其为我们提供的服务。