The changing boreal carbon cycle at the land-water-sediment interfaces

陆地-水-沉积物界面变化的北方碳循环

• 批准号: 543661-2019
• 负责人: Lapierre, JeanFrancois
• 金额: $ 9.27万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=693412
• 关键词: changing; boreal; carbon; cycle; land

The demand for low-carbon power is rapidly increasing across Canada due to recent developments in technologies and environmental policies that aim at reducing human impacts on the global climate. Hydro-power is perceived as a clean source of power by many Canadians, but damming carries an environmental footprint in terms of greenhouse gases emission and mercury levels that cannot be ignored, which is a hurdle for future developments in the country and exports of hydro-electricity. Moreover, this footprint depends on the underlying baseline fluxes of C and Hg that would occur even in the absence of reservoirs, but this baseline is rapidly changing in response to natural and human driven perturbations such as global warming, extremes in precipitation patterns, changes in atmospheric deposition, as well as forest fires. Full understanding of the net environmental footprint of hydro-power hence relies on two main aspects: a) accurate estimations of the fluxes of carbon and mercury in hydro-electric reservoirs over time and b) quantification of the natural fluxes of carbon and mercury at the landscape before dams were constructed. The latter is not trivial because very few estimates exist in the water-rich Canadian boreal biome and because existing estimates ignore the disproportionately important but understudied small water bodies. With the long term goal of disentangling the net effects of reservoirs on the cycling of C and Hg from shifts in natural baselines, we aim, with this project, to 1) quantify the modern and historical variation in carbon and mercury fluxes in comparison to the effect of reservoirs, 2) improve understanding of the movement and transformation of carbon from land to water across under-studied small water bodies, and 3) better understand the association between the cycling of carbon and mercury in aquatic ecosystems found in different regions across the boreal biome. To do so we will conduct field work focusing on the sampling of water and sediments of small lakes, wetlands in three regions of boreal Québec where there are major hydro-electric activity. We will further leverage existing geographic and field data to model past and future changes in the fluxes of carbon and mercury. The knowledge generated by this research will provide industries and managers with the data needed to refine the net environmental impacts of hydro-power for a better assessment of its competitiveness compared to other sources of energy as well as to hydro-power produced in other countries.

由于旨在减少人类对全球气候影响的技术和环境政策的最新发展，加拿大对低碳电力的需求正在迅速增加。水力发电被许多加拿大人视为一种清洁能源，但筑坝带来的温室气体排放和汞含量的环境足迹不容忽视，这是加拿大未来发展和水力发电出口的障碍。此外，这一足迹取决于即使在没有水库的情况下也会发生的潜在的碳和汞基线通量，但这一基线正在迅速变化，以应对全球变暖、极端降水模式、大气沉积变化以及森林火灾等自然和人类驱动的扰动。因此，充分了解水力发电的净环境足迹依赖于两个主要方面：a)对水电水库中碳和汞随时间变化的通量进行准确估计；b)对水坝建造前景观中碳和汞的自然通量进行量化。后者不是微不足道的，因为在加拿大水丰富的北方生物群落中存在很少的估计，因为现有的估计忽略了不成比例的重要但研究不足的小水体。为了从自然基线的变化中理清水库对碳和汞循环的净影响，我们的目标是，通过这个项目，1)量化碳和汞通量的现代和历史变化，与水库的影响进行比较，2)提高对碳从陆地到水的运动和转化的理解。3)更好地了解在寒带生物群系不同区域发现的水生生态系统中碳和汞循环之间的关系。为此，我们将进行实地工作，重点是在青海北部三个有主要水力发电活动的地区取样小湖泊和湿地的水和沉积物。我们将进一步利用现有的地理和实地数据，模拟碳和汞通量过去和未来的变化。这项研究所产生的知识将为工业和管理人员提供所需的数据，以改进水力发电的净环境影响，以便更好地评估其与其他能源和其他国家生产的水力发电相比的竞争力。