The release of carbon and pollutants from eastern canadian watersheds in response to atmospheric deposition and climate change

加拿大东部流域因大气沉降和气候变化而释放的碳和污染物

• 批准号: 576724-2022
• 负责人: Lapierre, JeanFrançoisJF
• 金额: $ 2.7万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 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=765156
• 关键词: release; carbon; pollutants; eastern; canadian

Canada's temperate and boreal landscapes host among the highest amounts and densities of lakes on earth. These lakes, most of them being hundreds to thousands of kilometers away from direct human activities, are experiencing changes in climate and atmospheric deposition of pollutants that disrupt the carbon and contaminant cycles, from their watershed to their water column. Past research has shown that lakes pH and concentrations of dissolved organic carbon (DOC) have been increasing in response to recovery from acidification, following legislation changes in the wake of widespread acid rain issues. These increases, which would in principle represent a return to pre-acidification conditions, have been accompanied by a loss in water transparency and shifts in thermal stratification, an increase in greenhouse gases emissions from aquatic ecosystems, and economic and health issues regarding drinking water treatment. Deposition of nitrogen and mercury have also decreased over the last decades, but the timing and amplitude of this decrease differed, and mercury persistence in watersheds may differ from that of ions and carbon. The cumulative effects of these trends in atmospheric deposition on the carbon and mercury cycles of Canadian temperate and boreal watersheds and lakes thus remain poorly understood. This proposal aims at filling this knowledge gap by building on extensive data available at Environment and Climate Change Canada at different spatial and temporal extents, including 100 lakes that have been sampled yearly since 1984 and 4 watersheds with contrasting climate and tree cover that have been monitored on a weekly basis since for several years in eastern Canada for geochemical properties in the water of lakes, streams, soils, throughfall and precipitation. We will complement these datasets by adding measurements of the composition of DOC as well as the concentrations of nutrients and different forms of total and methylated mercury in the water column of lakes and in key watershed compartments. Doing so, we will be able to better understand how industrial activities affect multiple facets of water quality at different spatial and temporal scales.

加拿大的温带和北方景观在地球上占地最高和密度。这些湖泊与直接人类活动相距数百到数千公里，正在经历着从水域到水柱的气候和大气沉积的变化，这些污染物的气候和大气沉积破坏了碳和污染物周期。过去的研究表明，随着广泛的酸雨问题的立法变化，湖泊pH和溶解有机碳（DOC）的浓度一直在响应于从酸化中恢复。这些增加原则上代表了恢复到酸性条件的回报，伴随着水透明度和热分层的转移，水生生态系统的温室气体排放量增加以及饮用水处理中的经济和健康问题。在过去的几十年中，氮和汞的沉积也有所减少，但是这种减少的时机和幅度有所不同，流域的汞持久性可能与离子和碳的汞持续存在不同。这些趋势在大气沉积中对加拿大温带和北方流域和湖泊的碳和汞周期的累积作用仍然知之甚少。 This proposal aims at filling this knowledge gap by building on extensive data available at Environment and Climate Change Canada at different spatial and temporal extents, including 100 lakes that have been sampled yearly since 1984 and 4 watersheds with contrasting climate and tree cover that have been monitored on a weekly basis since for several years in eastern Canada for geochemical properties in the water of lakes, streams, soils, throughfall and precipitation.我们将通过添加DOC组成的测量以及在湖泊水柱和关键流域室内的养分以及不同形式的总汞和甲基化汞的浓度来补充这些数据集。这样做，我们将能够更好地了解工业活动如何在不同的空间和时间尺度上影响水质的多个方面。