Carbon-climate interactions in hard-water lakes

现在人们普遍认为，湖泊是碳处理的重要节点，在全球碳收支中发挥着重要作用。需要更好地了解湖泊之间CO2变化的模式和根本原因，以改善对湖泊如何贡献和应对未来气候变化的预测。在软水、北方生态系统中进行的研究表明，对气候变化的大多数预测将导致这些湖泊二氧化碳排放量增加的正反馈循环。例如，北方湖泊预计将经历升高的温室气体产生的CO2浓度，因为大气温度的增加和有机碳负荷从流域的洪水事件的频率增加而升高。 相比之下，对占全世界内陆沃茨一半以上的硬水系统的气候和碳动态的了解要少得多。迄今为止的工作表明，硬水湖泊受到来自集水区的无机碳负荷的更强有力的调控，而且随着气候变暖，二氧化碳吸收量增加的负反馈机制更为普遍。 NSERC DG中提出的工作旨在通过能量通量（例如温度）和质量通量（例如降水）的气候参数的变化，建立对气候变化如何影响许多不同类型湖泊的湖泊碳处理的机械理解。了解内陆沃茨碳与气候之间的相互作用对于预测加拿大和整个地球仪未来的气候变化至关重要。* 我建议建立碳和气候之间的关系，在加拿大大草原的硬水湖泊1）制定准确的年度CO2预算的硬水和盐湖，通过测量浓度的CO2在每日和季节的时间尺度; 2）确定当地（在湖）的主要监管机构的CO2沿着不同的生产力和盐度的空间梯度;研究区域能量和质量通量变化（通过风暴、干旱和多雨期）如何影响湖泊CO2。这里提出的研究将导致一个可预测和可量化的框架，可以修改和适应其他系统，以制定更准确的CO2估计在整个连续的湖泊类型（低-高生产力，低-高碱度）世界各地。 这些目标合在一起，将有助于评估生态系统和景观一级的过程如何对大气温室气体浓度作出贡献和反应。

It is now widely accepted that lakes are important nodes of carbon processing and play a major role in the global carbon budget. A better understanding of the patterns and underlying causes of variability in CO2 among lakes is needed to improve predictions of how lakes will both contribute and respond to future climate change. Research conducted in soft-water, boreal ecosystems has shown that most projections of climate change will result in positive feedback loops with increasing CO2 emissions from these lakes. For example, boreal lakes are predicted to experience elevated respiratory-derived CO2 concentrations as the atmospheric temperature increases and organic carbon loadings from the watershed are elevated with increasing frequency of flooding events. In contrast, much less is known about the climate and carbon dynamics in hard-water systems, which comprise over half of the volume of inland waters worldwide. Work to date suggests that hard-water lakes are more strongly regulated by inorganic carbon loading from the catchment, and that negative feedback mechanisms, whereby CO2 uptake increases as the climate warms, are more prevalent. The work proposed in this NSERC DG seeks to establish a mechanistic understanding of how climate change affects lake carbon processing across many different types of lakes through variations in the climate parameters of Energy flux (e.g. temperature) and mass flux (e.g. precipitation). Understanding the interplay between carbon and climate in inland waters is critical in projecting the future of climate change in Canada and across the globe. *** I propose to establish the relationships between carbon and climate in hard-water lakes in the Canadian prairies by 1) developing accurate annual CO2 budgets for hard-water and saline lakes by measuring concentrations of CO2 at daily and seasonal time scales; 2) determining local (in-lake) chief regulators of CO2 along a spatial gradient of varying productivity and salinity; and 3) examining how regional Energy and mass flux variability (via storms, drought and pluvial periods) affect lake CO2. The research proposed here will lead to a predictive and quantifiable framework that can be modified and adapted to other systems to develop more accurate CO2 estimates across the continuum of lake types (low-high productivity, low-high alkalinity) worldwide. Together, these objectives will allow for the evaluation of how ecosystem and landscape level processes both contribute and respond to atmospheric greenhouse gas concentrations.