Diatom ecophysiology in a changing Arctic: consequences on the marine primary productivity

变化中的北极硅藻生态生理学：对海洋初级生产力的影响

• 批准号: RGPIN-2017-04505
• 负责人: Lavaud, Johann
• 金额: $ 2.33万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 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=684238
• 关键词: Diatom; ecophysiology; changing; Arctic; consequences

Arctic sea-ice shrinking opens new biogeographical and ecological frontiers that relate essential microscopic primary producers, i.e. the diatom microalgae, to human economic and social activities. In the context of current global warming, future trend of Arctic Ocean primary production, the substance of marine food-webs and vital support to the Northerners marine resources, is poorly understood. It particularly depends on intrinsically related paradoxes: 1) While longer periods and larger areas of free waters will open new territories for humans, they will be colonized by new diatoms, migrating from the Atlantic and Pacific, or being transported in the ballasts of commercial vessels using the new Northern maritime routes, 2) While a mild increase in light availability is predicted to enhance pan-Arctic marine production, too much sustained or episodic light could reduce the productivity of diatoms together with modifying their food quality' properties. These interlaced forthcoming events will modify the face of Arctic Ocean primary production, making it essential to understand the ecophysiological light-response of diatoms (growth, productivity and acclimation) under current and future light conditions. Arctic Ocean primary production is closely related to the seasonal diatom photosynthetic productivity and species succession. It integrates the functional and ecological diversity of growth and life forms, cell size, depth-adaptation. Therefore there is a need to comprehend how the functional and ecological diversity of Arctic diatoms light-response explains the present and future trends of Arctic marine primary production: this is the objective of my Discovery program proposal. It articulates around 4 short-term objectives: O1) Comparison of the growth and life forms, O2 and O3) Influence of cell size and depth-adaptation, and O4) Confrontation with potential future temperate invaders. My Discovery program proposal is supported by i) the precise knowledge of the diversity, ecology and environment of Arctic diatoms; ii) the unique access to a collection of strains, and the ability to grow them in Arctic-simulated conditions; iii) the ability to investigate photophysiology at the species and community levels with lab experiments and field monitoring; iv) a multidisciplinary approach coupling genetics, biochemistry and (eco-)physiology. Each objectives is interactively served by Tasks defining the research projects of 9 students: 3 B.Sc., 3 M.Sc. and 3 Ph.D. students. Furthermore, the collaborative foundation of my Discovery program proposal built on internationally acknowledged scientists from Canada and France will greatly contribute to the training of the next generation of Arctic and algae experts to support the better predictive sustainability of Arctic marine ecosystems in the context of accelerating global warming.

北极海冰的缩小开辟了新的地理学和生态学领域，将基本的微观初级生产者，即硅藻微藻，与人类的经济和社会活动联系起来。在当前全球变暖的背景下，北冰洋初级生产力的未来趋势，海洋食物网的实质和对北方海洋资源的重要支持，知之甚少。它特别依赖于内在相关的悖论：1）虽然更长的时间和更大面积的自由沃茨将为人类开辟新的领土，但它们将被新的硅藻殖民，从大西洋和太平洋迁移，或使用新的北方海上航线在商业船只的压载物中运输，2）虽然预计光照可用性的温和增加将提高泛北极海洋生产，过多的持续或间歇性光照会降低硅藻的生产力，并改变其食物品质的特性。这些交错的即将发生的事件将改变北冰洋初级生产的面貌，这使得了解硅藻在当前和未来光照条件下的生理生态光响应（生长，生产力和适应）至关重要。北冰洋初级生产力与季节性硅藻光合生产力和物种演替密切相关。它整合了生长和生命形式、细胞大小、深度适应的功能和生态多样性。因此，有必要了解北极硅藻光响应的功能和生态多样性如何解释北极海洋初级生产的现状和未来趋势：这是我的发现计划提案的目标。它阐明了大约4个短期目标：O 1）生长和生命形式的比较，O2和O3）细胞大小和深度适应的影响，以及O 4）与潜在的未来温带入侵者的对抗。我的发现计划提案得到了以下方面的支持：i）对北极硅藻多样性，生态和环境的精确了解; ii）获得菌株集合的独特途径，以及在北极模拟条件下培养它们的能力; iii）通过实验室实验和现场监测在物种和群落水平上调查生物生理学的能力; iv）结合遗传学、生物化学和（生态）生理学的多学科方法。每个目标都由定义9名学生研究项目的任务交互式服务：3名B.Sc.，3名硕士和3名博士学生此外，我的发现计划提案的合作基础建立在来自加拿大和法国的国际公认的科学家的基础上，将大大有助于培训下一代北极和藻类专家，以支持在全球变暖加速的背景下更好地预测北极海洋生态系统的可持续性。