Collaborative Research: BoCP-Implementation: The influence of different nutrient delivery modes on functional biodiversity of marine plankton in a changing ocean

所有有生命的有机体都必须从环境中获取营养才能生存和生长。海洋中的浮游植物和它们的浮游动物食草动物也不例外，它们构成了地球上最大的食物网的基准面，并在全球碳循环中发挥着至关重要的作用。然而，关于向海洋生态系统输送营养物质的不同物理机制如何构建浮游生物多样性和相互作用网络以及它们的营养依赖性的规则知之甚少。该项目研究了这些特定的物理机制如何通过增加对混合层的营养输入来影响浮游生物群落的功能性生物多样性，从而在不断变化的海洋环境中产生强烈的、也许是可预测的生物变异性。这项研究揭示了不同时空尺度的环境干扰如何影响生态系统功能，并阐明了分类生物多样性和功能多样性之间关于生态系统稳定性的动态变化。从这个项目中获得的关于控制生产力和生物多样性的见解适用于全球许多岛屿和上升流系统。让当地伙伴参与收集更多的观察结果并将研究结果传播给加拉帕戈斯社区，可以就系统运行和土著社区因气候变化而面临的问题进行双向对话。该项目还为来自代表性不足群体的研究生和本科生以及一名K-12教师提供培训。该项目将实地研究和实验室研究与模拟工作相结合，以评估不同的营养物质输送方式是否对营养物质的可获得性施加足够的控制，从而影响浮游生物的功能多样性和相关的动态。研究地点是赤道太平洋东部的加拉帕戈斯群岛，在那里进行密集的船上采样的同时，部署了为期12个月的垂直剖面系泊设备，以观察：1)孤立的岛屿尾流；2)群岛与赤道暗流和群岛西侧上升流的相互作用。据信对该系统有重大影响的内部潮汐也被观测到。浮游生物的不同功能特征，如营养获取策略和储存，正在被测量，以调查它们是否被这些输入所选择。巡航和更长期的观测工作产生了物理、化学和生物特性的空间调查和时间序列。使用从该地区获得的浮游植物分离株的实验室培养研究被用来量化浮游植物与养分获取和储存有关的功能特征。这些结果为浮游生物NPZ模型的参数化提供了信息，该模型由代表三种物理模式的营养物质输送的时间序列强制，用于测试自下而上的控制是否能够解释观测到的分布和时间变异性。这项研究通过检验功能冗余驱动生态系统稳定性这一假说，推动了生物多样性动力学和功能生物多样性的生态学理论。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

All living organisms must acquire nutrients from their environment to survive and grow. Phytoplankton and their zooplankton grazers in the ocean, which constitute the base levels of the planet’s largest food webs and play an essential role in global carbon cycling, are no exception. However, the rules governing how different physical mechanisms of nutrient delivery to marine ecosystems structure plankton biodiversity and interaction networks along with their trophic dependencies are poorly understood. This project examines how these specific physical mechanisms influence the functional biodiversity of plankton communities through increasing nutrient inputs into the mixed layer, leading to strong, yet perhaps predictable biological variability in a changing ocean environment. This research reveals details on how environmental disturbances of varying spatial and temporal scales affect ecosystem function and elucidates the dynamics between taxonomic biodiversity and functional diversity with respect to ecosystem stability. Insights gained from this program about controls on productivity and biodiversity are applicable to many island and upwelling systems globally. Engagement of local partners to collect additional observations and dissemination of research findings to the Galápagos community enable a two-way dialog about system function and the issues faced by the indigenous community due to climate change. The project also provides training for graduate students and undergraduates from underrepresented groups and a K-12 teacher.This project combines field and laboratory studies with a modeling effort to evaluate if different physical modes of nutrient delivery, in close proximity to each other, exert sufficient controls on nutrient availability that influences plankton functional diversity and associated dynamics. The study site is the Galápagos archipelago in the eastern equatorial Pacific Ocean where intensive shipboard sampling is augmented by 12-month deployments of a vertical profiler mooring to observe i) an isolated island wake and ii) interaction of the archipelago with the Equatorial Undercurrent (EUC) and upwelling on the western side of the archipelago. Internal tides, believed to have a significant influence on the system, are also being observed. Varying functional traits of plankton such as nutrient acquisition strategies and storage are being measured to investigate whether they are selected upon by these inputs. The cruise and longer-term observational efforts generate a spatial survey and time series of physical, chemical and biological properties. Laboratory culture studies using phytoplankton isolates obtained from the region are used to quantify phytoplankton functional traits in relation to nutrient acquisition and storage. The results inform parameterization of a plankton NPZ model forced by time series of nutrient delivery representative of the three physical modes at play, used to test if bottom-up control can explain observed distributions and temporal variability. This research advances ecological theory on biodiversity dynamics and functional biodiversity by testing the hypothesis that functional redundancy drives ecosystem stability, achieved through resistance to change or resiliency.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.