Collaborative Research: Scaling up from community to meta-ecosystem dynamics in the rocky intertidal - a comparative-experimental approach

元生态系统概念假设生态群落的动态反映了局地尺度和生态系统过程之间的相互依存关系，这些过程在很大程度上是不同的。因此，群落之间的变化不仅取决于局部变化的物种相互作用和非生物因素，如物理干扰，还取决于区域和全球变化的生态系统过程，如营养物质和碳等物质的扩散和流动。岩石潮间带群落及其变化因素的研究解决了元生态系统动力学问题。该项目的目标是了解营养物质和浮游植物等海洋补贴的变化如何影响北加州洋流大型海洋生态系统中的底栖生物群落结构。俄勒冈州和加利福尼亚北部海岸上升流的局地尺度变化将用于了解营养和生产力的变化如何影响底栖-上层海洋耦合，其对底栖物种相互作用的影响，以及最终的岩质潮间带群落结构。利用以海水温度为自变量的概念模型，预测了营养物和光对低潮间带海洋底栖生物和远洋初级生产的双重影响如何产生不同的群落结果。群落结构的两个“端点”是滤食性无脊椎动物和大型藻类的优势。该模型预测，在低（冷）SWT条件下，养分和光有效性高，以大型植物为主。在非常高的营养和光照条件下，具有竞争优势的海带将占优势，并可能促进不耐胁迫的大藻物种，随着营养和光照的减少，海带的优势将转变为表面草和叶藻的优势。随着高（暖）SWT，条件有利于高浮游植物产量，导致无根无脊椎动物的优势。高浮游植物还造成低光照和低营养条件，对大型藻类的生长及其与无根无脊椎动物竞争的能力产生负面影响。研究将在研究区域1300公里范围内的5个角内的15个地点进行。一项水采样计划将量化营养物和浮游植物的浓度，现场部署的远程传感器将提供光和叶绿素A的时间序列估计，调查将量化群落结构。可操作的野外实验将测试物种相互作用对群落结构的作用，以及相互作用如何随生态补贴而变化。更广泛的影响：三个pi （Hacker, Menge, Nielsen）有本科和研究生的教学责任，包括海洋生态学的指导和培训。每个机构都作出重大努力，促进代表性不足的群体参与实验室和实地活动；Menge、Hacker和Nielsen''‘’的实验室小组大部分或全部由女性组成。尼尔森‘’‘’在索莫纳州立大学（SSU）的职位，这是一所四年制本科院校，很少有资助的研究项目，为SSU的本科生提供了一个难得的机会，参与一流的研究体验。最后，这项工作将深入了解由于人类活动和气候变化而预测的上升流制度变化的后果，从而赋予研究社会意义。了解底-上层耦合对岩石潮间带群落动态的重要性，对于管理和保护面临人类引起的气候变化的海洋群落至关重要。pi将与政策和外展计划合作，将学术界以外的研究传播给更广泛的公众和利益相关者。

The meta-ecosystem concept hypothesizes that the dynamics of ecological communities reflect interdependence between local-scale and ecosystem processes that vary across large distances. Thus, variation among communities depends not only on locally-varying species interactions and abiotic factors, such as physical disturbance, but also on regionally- and globally-varying ecosystem processes, such as dispersal and flows of materials such as nutrients and carbon. This study of rocky intertidal communities and the factors underlying their variation addresses the issue of meta-ecosystem dynamics. The goal of this project is to understand how variability in oceanographic subsidies, such as nutrients and phytoplankton, influences benthic community structure in the northern California Current Large Marine Ecosystem. Local-scale variation in upwelling along the Oregon and northern California coasts will be used to understand how changes in nutrients and productivity influence benthic-pelagic coupling, its effect on benthic species interactions, and ultimately rocky intertidal community structure. A conceptual model, in which the independent variable is seawater temperature (SWT), is used to predict how the dual effect of nutrients and light on marine benthic and pelagic primary production generates different community outcomes in the low intertidal zone. The two ""endpoints" of community structure are a dominance of filter feeding invertebrates or macroalgae. The model predicts that with low (cold) SWT, nutrient and light availability is high, and macrophytes are dominant. Under very high nutrients and light, competitively dominant kelps will prevail and possibly facilitate stress-intolerant macroalgal species, and as nutrients and light diminish, kelp dominance should switch to dominance by surfgrass and foliose understory algae. With higher (warmer) SWT, conditions favor high phytoplankton production, leading to dominance by sessile invertebrates. High phytoplankton also creates low light and low nutrient conditions, negatively affecting growth of macroalgae and their ability to compete with sessile invertebrates. Research will be conducted at 15 sites nested within five capes spanning the 1300 km range of the study region. A water sampling program will quantify concentrations of nutrients and phytoplankton, field-deployed remote sensors will provide time-series estimates of light and chlorophyll a, and surveys will quantify community structure. Manipulative field experiments will test the role of species interactions on community structure and how interactions vary with ecological subsidies.Broader Impacts: 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; Menge, Hacker and Nielsen''''s lab groups consist mostly or entirely of women. Nielsen''''s position at Somona State University (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. Finally, the work will provide insight into the consequences of predicted changes in upwelling regimes due to human activity and climate change, thereby giving the research societal significance. Knowledge of the importance of benthic-pelagic coupling to the dynamics of rocky intertidal communities is crucial to manage and conserve marine communities facing human-induced variation in climate. The PIs will work with a policy and outreach program to communicate the research beyond academic circles to the wider public and stakeholders.