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

加拿大数以百万计的湖泊对我们的身份至关重要。我们把淡水视为最重要的自然资源。为了保护这种资源，我们需要更好地了解湖泊的功能，以及集水区如何决定湖泊中碳(对所有生命至关重要，是二氧化碳和甲烷等温室气体，并为水提供颜色)的命运，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溶解的有机碳(赋予天然水颜色的物质)，以便使其能够在没有高浓度消毒副产品的情况下进行处理。气候变化对从集水区向源头湖输出水和碳的影响以及碳在这些湖泊中的去向知之甚少。小湖泊是很好的模式生态系统，因为它们足够大，可以容纳从微生物到鱼类的整个食物网，大小不一，并且可以从它们的集水区产生广泛的影响。小湖泊也是很好的变革哨兵。实验湖地区和多塞特环境科学中心提供了一个难得的机会来研究集水区在驱动颜色、缺氧风险、饮用水的可处理性以及跨气候梯度的湖泊中碳的去向方面所起的作用。此外，将他们各自几十年的研究和监测与新颖的分析相结合，提供了一种独特和令人兴奋的方法。有明显证据表明，湖泊正在因气候变化而改变，例如，夏季较长时间的层结使底层水更频繁地缺氧，湖泊集水区碳和营养物质负荷的季节性变化影响它们的命运。*到目前为止，很少有研究将集水区特征(例如土地覆盖类型、坡度、海岸线形状因素和集水湖比)与溶解有机碳质量(例如不同类型的荧光、粒度分级和消毒副产品形成)相结合，以了解不同类型的有机碳在源头湖中的命运。拟议中的研究将在这一方向上迈出第一大步。这项研究的结果将被用来确定更适合饮用水供应的湖泊类型。这对长期面临安全饮用水问题的北部社区至关重要。最终，需要开发模型来预测气候变化对湖泊中碳的命运的影响，以保护这些湖泊的健康和为我们提供的服务。

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.