The biogeography of primary producers in the subpolar North Atlantic

智力优势：硅藻和甲藻都是种类繁多、在地球化学上具有重要意义的浮游生物。前者生长速度快，占主导地位，其矿物硅酸盐成分有助于推动大量出口。后者包括多种营养策略，包括混合营养，并在碳和营养物质的循环中发挥复杂的作用。目前的海洋生态系统模型通常代表一个单一的硅藻“功能类型”，并没有明确反映甲藻或兼养。该项目将调查和模拟亚极地北大西洋硅藻和甲藻组合的区域地理学、季节演替和年际变化，在那里，连续浮游生物记录仪调查记录了几十年来这些生物的100多个物种的丰度。在CPR调查中，PI将描述硅藻和甲藻组合的时空变化及其关键特征，包括细胞大小和营养策略。他们将使用聚类分析，根据这两个主要初级生产者群体的物种和特征组合的变化，推断出亚极地北大西洋的地理省。为了解释环境和生理学的相互作用如何调节这些空间和时间趋势，他们将开发和采用对北极北大西洋的数值模拟，其中包括一个生态系统组件，其中数百种潜在可行的微生物生理学被播种，“适者生存”在计算机上组织生态系统结构和功能。模拟将被用来寻求机械的解释以前注意到的年际和十年的变化硅藻和甲藻丰度在北Atlantic.Broader Impacts：拟议的工作是从根本上跨学科的性质。它通过欧盟/北美BASIN计划促进国际合作。开发的工具将在全球变化和碳循环模型以及植根于这两个群体的古记录的气候变化和微生物进化研究中具有潜在的应用。该项目涉及培养和培训一名研究生和博士后科学家。

Intellectual Merit: Diatoms and dinoflagellates are both diverse and biogeochemically significant groups of plankton. The former have fast growth rates, dominate blooms and their mineral silicate components help drive significant export. The latter encompass diverse trophic strategies including mixotrophy and play a complex role in the cycling of carbon and nutrients. Current marine ecosystem models typically represent a single diatom "functional type" and do not explicitly reflect dinoflagellates or mixotrophy at all. This project will investigate and model the regional biogeography, seasonal succession, and inter-annual variability of the assemblages of diatoms and dinoflagellates in the subpolar North Atlantic, where the Continuous Plankton Recorder (CPR) survey has documented the abundance of more than 100 species of these organisms over several decades. The PIs will characterize the temporal and spatial variations of diatom and dinoflagellate assemblages and their key traits, including cell size and trophic strategy, in the CPR survey. They will use cluster analysis deduce biogeographic provinces in the subpolar North Atlantic based on the variations in species and trait assemblages of these two key groups of primary producers. To interpret how the interplay of environment and physiology regulates these spatial and temporal trends, they will develop and employ numerical simulations of the supolar North Atlantic which includes an ecosystem component where hundreds of potentially viable microbial physiologies are seeded and "survival of the fittest" in silico organizes ecosystem structure and function. Simulations will be used to seek mechanistic explanations for the previously noted interannual and decadal shifts in diatom and dinoflagellate abundance in the North Atlantic.Broader Impacts: The proposed work is fundamentally interdisciplinary in nature. It fosters international collaborations through the EU/North American BASIN program. The tools developed will have potential applications in models of the global change and the carbon cycle, as well as studies of climate change and microbial evolution rooted in the paleo-record of these two groups. The project involves the development and training of a graduate student and post-doctoral scientist.