Environmental forcing of primary production in arctic and subarctic seas

北极和亚北极海域初级生产的环境强迫

• 批准号: 327493-2006
• 负责人: Tremblay, JeanEric
• 金额: $ 1.54万
• 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: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=397803
• 关键词: Environmental; forcing; primary; production; arctic

Boreal marine ecosystems are highly sensitive to climate change. Perturbations are most acute in the Arctic, where temperature increases steadily and the ice cover declines rapidly. Hemispheric changes in the circulation of oceanic water masses, the incidence of extreme weather events and the freshwater content of the upper ocean alter vertical mixing in surface waters and the long-range dispersal of nutrients and organisms. Through their effects on the growth conditions of phytoplankton, these changes are likely to affect food webs and the oceanic drawdown of atmospheric CO2 (which mitigates global warming). Our present knowledge of phytoplankton ecology in relation to climate variability and change is insufficient to assess the current and future state of northern marine ecosystems. The long-term objective of the proposed research is to quantify and predict the major effects of environmental forcing on primary production in Arctic and subarctic seas. Two fundamental questions will be addressed by the initial five-year plan: what controls the (1) species dominance and (2) magnitude of primary production? Data from ship-based process studies, in situ sampling observatories and controlled experiments with phytoplankton cultures will be combined to test the working hypotheses. A suite of key phytoplankton variables will be quantified with and without experimental manipulations of light, temperature and nutrients. Bloom-forming phytoplankton will be isolated and taken to the home laboratory to quantify their growth dynamics across gradients of light, temperature and nutrients. Collectively, the results are expected to increase our fundamental understanding of phytoplankton processes and provide the data necessary to parameterize models and simulations of environmental forcing. The benefit to Canada will be greater knowledge of critical ecosystem processes and, in the longer term, greater capacity to anticipate and manage change in climate and marine renewable resources.

北方海洋生态系统对气候变化高度敏感。北极的扰动最为严重，那里的温度稳步上升，冰层覆盖迅速减少。海洋水团环流的半球变化、极端天气事件的发生以及上层海洋的淡水含量改变了表层沃茨的垂直混合以及营养物和生物的远距离扩散。通过对浮游植物生长条件的影响，这些变化可能会影响食物网和海洋大气中二氧化碳的减少（减缓全球变暖）。我们目前对浮游植物生态与气候变异和变化的关系的了解不足以评估北方海洋生态系统的当前和未来状况。拟议研究的长期目标是量化和预测环境强迫对北极和亚北极海洋初级生产的主要影响。最初的五年计划将解决两个基本问题：（1）物种优势和（2）初级生产的规模是什么控制的？将综合来自船基过程研究、现场取样观测站和浮游植物培养受控实验的数据，以检验工作假设。一套关键的浮游植物变量将被量化，没有实验操作的光，温度和营养物质。形成水华的浮游植物将被隔离并带到家庭实验室，以量化它们在光照、温度和营养梯度下的生长动态。总的来说，这些结果有望增加我们对浮游植物过程的基本了解，并为参数化模型和环境强迫模拟提供必要的数据。对加拿大的好处是，它将更多地了解关键的生态系统进程，从长远来看，它将更有能力预测和管理气候和海洋可再生资源的变化。