Collaborative Research: Intertidal community assembly and dynamics: Integrating broad-scale regional variation in environmental forcing and benthic-pelagic coupling

缅因湾（GoM）的潮间带岩石栖息地为研究自然群落的结构和动态提供了一个模型系统。在整个缅因湾，在这些栖息地经常发现相同的物种，但在3个不同的地区（墨西哥湾南部、中部和北部），群落结构、动态和生产力明显不同。过去主要在墨西哥湾南部和中部进行的有影响力的工作侧重于推动潮间带群落结构的当地过程，但对这些群落的结构产生了非常不同的概念模型。该项目考察了岩岸群落过程的区域差异是否由温度、食物供应和近岸海岸海洋学的区域变化所形成的招募差异所驱动。该项目将提高对大规模环境力量如何与局部过程相互作用以控制物种分布以及这些群落的结构和动态的理解。了解在不同尺度上运行的过程之间的相互作用，对于开发更可靠的模型来预测社区动态至关重要。此外，这个项目产生的数据将对具有重要商业价值的物种的区域动态以及墨西哥湾内的生态系统和渔业管理产生重要影响。作为这个跨学科项目的一部分，学生和博士后研究人员将得到支持和培训。该项目的总体假设是，社区层面过程的区域差异是由少数关键物种的种群连通性和招募模式的差异驱动的，这些差异最终是由温度和食物供应的区域差异引起的，并由物理幼虫运输过程介导。因此，该项目将通过野外实验、野外采样、连通性估计和综合建模来验证以下假设：1)浮游生物幼虫净出口地区（墨西哥湾北部），局部分散的物种主导动态，而浮游生物幼虫主导种群间高定居和广泛连通性地区（墨西哥湾南部）的动态。(2)浮游幼虫种群沉降密度由北向南呈增加趋势，与食物供应的区域差异一致。3)种群连通性在区域之间差异很大，区域之间的自种子或作为幼虫来源与吸收的程度不同；自播导致墨西哥湾中部相对局部化的种群动态。4)种群连通性模式是由物理运输过程驱动的，可以用基本幼虫行为模型和循环模型耦合来表示。在墨西哥湾约600公里的18个不同地点，调查将评估招聘、食物供应和二次生产力的变化，实验将评估波浪暴露和庇护栖息地的社区进程。该项目将使用水文、当前剖面和幼虫垂直分布调查来收集幼虫/环流耦合模型的数据。种群连通性将使用元素指纹进行建模和经验评估（针对一个物种）。空间明确的元社区模型将整合所有项目组成部分，并测试区域和地方进程在控制社区组织和动态方面的相对重要性。

Rocky intertidal habitats in the Gulf of Maine (GoM) provide a model system to examine the structure and dynamics of natural communities. Throughout the Gulf of Maine, the same species are often found in these habitats but community structure, dynamics and productivity differ markedly among 3 distinct regions (southern, central and northern GoM). Past influential work, conducted primarily in the southern and central GoM, focused on the local processes driving intertidal community structure but produced very different conceptual models of how these communities are structured. This project examines whether regional differences in rocky shore community processes are driven by differences in recruitment that are shaped by regional variation in temperature and food availability and nearshore coastal oceanography. This project will improve the understanding of how large-scale environmental forces interact with local processes to control the distribution of species and the structure and dynamics of these communities. Understanding the interaction between processes operating at different scales is fundamentally important to developing more reliable models that can be used to predict community dynamics. In addition, data resulting from this project will have important implications for regional dynamics in commercially important species and for ecosystem and fisheries management within the GoM. Students and postdoctoral researchers will be supported and trained as part of this interdisciplinary project. The overarching hypothesis of this project is that regional differences in community-level processes are driven by very different patterns of population connectivity and recruitment in a few key species and that these differences are ultimately caused by regional variation in temperature and food availability and mediated by physical larval transport processes. Hence, the project will test the following hypotheses with manipulative field experiments, field sampling, connectivity estimates, and integrative modeling: 1) Locally-dispersing species dominate dynamics in regions with a net export of planktonic larvae (Northern GoM), while species with planktonic larvae dominate the dynamics in regions with high settlement and extensive connectivity among populations (Southern GoM). 2) Settlement density of species with planktonic larvae increases from northern to southern regions in accord with regional variation in food availability. 3) Population connectivity varies greatly among regions, with regions differing in the degree to which they are self-seeded or serve as larval sources vs. sinks; self-seeding leads to relatively localized population dynamics in the middle portion of the GoM. 4) Patterns of population connectivity are driven by physical transport processes and can be represented by coupling basic larval behavior models with circulation models. At 18 different sites in the GoM across ~ 600 km, surveys will evaluate variation in recruitment, food availability and secondary productivity and experiments will assess community processes in wave-exposed and sheltered habitats. The project will use hydrographic, current profile, and larval vertical distribution surveys to collect data for coupled larval/circulation models. Population connectivity will be both modeled and empirically evaluated (for one species) using elemental fingerprinting. A spatially explicit metacommunity model will integrate across all project components and test the relative importance of regional and local processes in controlling community organization and dynamics.