The carbon cycling of eastern Quebec boreal forests in the context of climate change and hydropower production

水电是魁北克人和加拿大人的主要电力来源，也是对美国越来越重要的出口产品。用于水力发电的水库注水会排放二氧化碳和甲烷这两种重要的温室气体。与不可再生资源发电相比，这些排放量很低，但必须考虑到气候变化导致的快速变化的环境。事实上，除了水生和湿地生态系统外，水库还淹没了以前主要是森林的地区。一般认为，这些是净碳汇，但在气候变暖的情况下，这种情况可能会发生变化，因为干旱、火灾和昆虫流行可能变得更加频繁。因此，为了能够预测水电站对气候的净影响，我们需要了解完整的周围景观对气候的影响，以及这种影响是如何演变的。我们建议为位于魁北克省Côte北部地区的La Romaine流域这样做。La Romaine综合项目于2009年启动。该综合体将于2021年完工，包括4座水力发电厂，年发电量为8.5太瓦时，4座水库总面积为280平方公里。对拉罗梅因河某小流域的碳通量进行监测，确定小流域内的碳储存热点，确定小流域水输出碳的命运。我们将利用这项详尽的实地研究的结果来模拟拉罗梅因下游流域的碳功能，最终能够预测这片森林景观在碳循环中的作用。我们的项目不仅可以帮助魁北克省负责发电、输电和配电的公用事业公司（hydro - qubec）评估水电生产的真实环境成本，还可以更好地为加拿大的战略提供信息，即部分依赖其森林的碳汇功能来缓解未来的气候变化。

Hydropower is the main source of electricity to Quebecers and to Canadians, and is an increasingly important export product to the US. Reservoir flooding for hydropower production emits carbon dioxide and methane, two important greenhouse gases. These emissions are low compared to electricity production from non-renewable resources, but they have to be put in the context of a rapidly changing environment due to climate change. Indeed, reservoirs flood areas that were previously largely forests, in addition to aquatic and wetland ecosystems. It is generally assumed that these are net carbon sinks, but this may change in a warmer climate, where droughts, fire and insect epidemics may become more frequent. Hence, to be able to project the net impact of hydropower reservoirs on the climate, we need to understand the impact of intact, surrounding landscapes on the climate, and how this impact evolves. We propose to do this for the La Romaine watershed located on the Côte Nord region of the province of Quebec. The La Romaine complex project was initiated in 2009. At completion in 2021, the complex will comprise four hydroelectric power plants yielding 8.5 TWh of energy per year and four reservoirs covering a total area of 280 km2. We will monitor the carbon fluxes of a subwatershed of La Romaine river, determine the carbon storage hotspots within the subwatershed, and determine the fate of carbon exported in the water from the subwatershed. We will use the results from this exhaustive field study to model the carbon functions of the lower La Romaine watershed, to eventually be able to project the role of this forested landscape in the carbon cycle. Our project will not only be useful to the utility responsible for generation, transmission, and distribution of electricity in the province of Quebec (Hydro-Québec) to assess the true environmental cost of hydropower production, but also to better inform Canada's strategy to partly rely on the carbon sink function of its forests to mitigate future climate change.