Collaborative Research: The role of calcifying algae as a determinant of rocky intertidal macrophyte community structure at a meta-ecosystem scale

环境压力模型最近已被修改，以加入促进的影响，以加入诸如捕食、竞争和非生物压力等负面影响，作为群落结构的决定因素。然而，我们对调节跨系统促进效应的表达的过程以及促进放大或抑制气候变化的生态后果的潜力的经验了解仍然有限。该项目侧重于更广泛的元生态系统概念中的促进动力学，该概念假设群落之间的差异不仅取决于局部变化的物种相互作用和非生物因素的影响，如环境压力和物理干扰，而且还取决于区域和全球变化的生态系统过程，如养分和碳等物质的扩散和流动。研究人员将研究珊瑚藻类草皮与形成树冠的大型植物(包括海带和冲浪草)之间潜在的关键促进作用的影响，这些植物位于岩石潮间带的半生态系统中。这项研究将在气候变化的背景下进行，重点是大型植物-珊瑚的相互作用如何受到海洋条件的影响，包括由不同的上升流(温度、营养物质、浮游植物丰度和光照)和海洋酸化加剧驱动的因素，这些因素在俄勒冈州和加利福尼亚州北部的加利福尼亚州北部洋流(NCC)海岸以镶嵌模式变化。该项目的目标是检验这一假设，即珊瑚草皮-大型植物树冠相互作用是确定低岩石群落结构的基本相互作用，这种相互作用的破坏将显著改变这种以海藻和冲浪草为主的群落的结构和功能。该项目将利用和加强在NCC沿海元生态系统中建立的一个研究平台，该平台跨越17个站点，横跨约800公里，先前NSF将在每个站点提供资金：(1)量化海洋状况，包括温度、营养物质、浮游植物、光(PAR)和碳酸盐化学，以记录跨元生态系统镶嵌的群落结构海洋变化的响应；(2)进行实地实验，测试珊瑚藻类草坪(主要是珊瑚)与优势树冠物种--海带无柄海藻和海草毛竹之间的相互作用；以及(3)开展以相互作用机理为重点的实验室实验，特别是测试碳酸盐化学、光、温度和营养物质的影响。组成部分(1)将使用部署在潮间带的远程传感器(荧光计、温度传感器、PAR传感器和最近开发的pH传感器)和直接采样(营养物、浮游植物、二氧化碳和pH)，以量化底栖生物初级生产者在空间尺度上对资源、能源和环境压力的原位暴露制度。这些指标将与新开发的用于量化上升流强度的局部尺度变化的指数相结合，以表征气候强迫和生态系统状态之间的联系。将海洋学与我们的野外和实验室实验相结合，将为未来岩质潮间带生态系统的现状可能如何改变提供独特而有价值的见解。该项目将贡献首批研究之一，以测试生态系统规模上不同的上升流和二氧化碳对社区的影响。这些因素如何改变关键物种的直接和间接相互作用，对于我们努力了解田间生态系统将如何应对气候变化具有至关重要的意义。这些知识对于我们管理和保护面临人为气候变化的海洋社区的努力至关重要。该项目将以多种方式整合研究和教育。其中三名PI(Hacker、Menger、Nielsen)负有本科生和研究生的教学职责，涉及海洋生态学方面的教学和培训。每个组织都作出重大努力，促进代表人数不足的群体参与实验室和实地活动。尼尔森在SSU的职位为SSU提供了一个难得的机会，为SSU本科生提供了参与一流研究体验的难得机会。SSU是一所四年制本科院校，几乎没有资助的研究项目。所有私人投资机构都参与海洋保护区的区域规划。最后，这项工作将提供对沿海海洋地区由于人类活动和由此导致的气候变化而预测的变化的后果的洞察，从而赋予该研究社会意义。PIS将与政策和外联计划合作，将研究成果传达给学术界以外的更广泛的公众和利益相关者。

Environmental stress models have recently been modified to incorporate the influence of facilitation to join negative effects such as predation, competition, and abiotic stress as determinants of community structure. Nevertheless, our empirical understanding of the processes that regulate the expression of facilitation effects across systems and the potential for facilitation to amplify or dampen the ecological consequences of climate change remains limited. This project focuses on facilitation dynamics in the broader meta-ecosystem concept, which hypothesizes that variation among communities depends not only on locally-varying species interactions and impacts of abiotic factors such as environmental stress and physical disturbance but also on regionally- and globally-varying ecosystem processes such as dispersal and flows of materials such as nutrients and carbon. The investigators will study the influence of a potentially critical facilitative interaction between coralline algal turfs and canopy-forming macrophytes including kelps and surfgrass in a rocky intertidal meta-ecosystem. The research will be conducted in a climate change context, with a focus on how the macrophyte-coralline interaction is influenced by ocean conditions, including factors driven by variable upwelling (temperature, nutrients, phytoplankton abundance, and light) and increases in ocean acidification, which vary in a mosaic pattern along the coast of the northern California Current (NCC) in Oregon and northern California.The goal of the project is to test the hypothesis that the coralline turf-macrophyte canopy interaction is a cardinal interaction in the determination of low rocky intertidal community structure, and that disruption of this interaction would dramatically alter the structure and function of this kelp- and surfgrass-dominated assemblage. The project will take advantage of, and enhance, a research platform established across 17 sites spanning ~800 km in the NCC coastal meta-ecosystem with prior NSF funding that will at each site: (1) quantify ocean conditions, including temperature, nutrients, phytoplankton, light (PAR), and carbonate chemistry to document the response of community structure oceanographic variation across a meta ecosystem mosaic; (2) carry out field experiments testing the nature of the interaction between coralline algal turfs (primarily Corallina vancouveriensis) and dominant canopy species, the kelp Saccharina sessile and the surfgrass Phyllospadix scouleri; and (3) carry out laboratory experiments focusing on the mechanism of the interaction, specifically testing the effects of carbonate chemistry, light, temperature, and nutrients. Component (1) will employ both remote sensors deployed in the intertidal (fluorometers, thermal sensors, PAR sensors, and a recently developed pH sensor) and direct sampling (nutrients, phytoplankton, pCO2, and pH) to quantify the in situ exposure regime of benthic primary producers to resources, energy, and environmental stress across spatial scales. These metrics will be combined with a newly developed index for quantifying local-scale variation in upwelling intensity to characterize the linkages between climate forcing and ecosystem state. Coupling oceanography with our field and laboratory experiments will provide unique and valuable insights into how the current state of rocky intertidal ecosystems is likely to be altered in the future.Intellectual Merit. The project will contribute one of the first studies to test the community consequences of varying upwelling and CO2 across an ecosystem scale. How these factors alter the direct and indirect interactions of key species is of fundamental importance in our efforts to learn how field ecosystems will respond to climate change. Such knowledge is crucial to our efforts to manage and conserve marine communities facing human-induced variation in climate.Broader Impacts. The project will integrate research and education in a variety of ways. Three of the PIs (Hacker, Menge, Nielsen) have undergraduate and graduate teaching responsibilities, which involve instruction and training in marine ecology. Each makes a major effort to foster the participation of underrepresented groups in lab and field activities. Nielsen's position at SSU, a four-year undergraduate institution with few funded research programs, offers a rare chance for SSU undergraduates to participate in a first-rate research experience. All PIs are engaged in regional planning for marine protected areas. Finally, the work will provide insight into the consequences of predicted changes in coastal oceanic regions due to human activity and resulting climate change, thereby giving the research societal significance. The PIs will work with a policy and outreach program to communicate the research beyond academic circles to the wider public and stakeholders.