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

缅因湾岩石潮间带生境(GOM)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，相同的物种经常出现在这些栖息地，但3个不同地区(南部、中部和北部)的群落结构、动态和生产力明显不同。过去有影响力的工作主要在南部和中部进行，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截然不同的概念模型。该项目审查岩石海岸群落进程的区域差异是否由区域温度和食物可获得性差异以及近岸沿海海洋学所形成的招募差异所驱动。该项目将增进对大规模环境力量如何与当地进程相互作用以控制物种分布以及这些社区的结构和动态的了解。了解在不同尺度上运行的过程之间的相互作用对于开发可用于预测社区动态的更可靠的模型至关重要。此外，该项目产生的数据将对重要商业物种的区域动态以及全球海洋观测系统内的生态系统和渔业管理产生重要影响。学生和博士后研究人员将作为这一跨学科项目的一部分得到支持和培训。该项目的主要假设是，社区一级进程的区域差异是由几个关键物种的种群连接和招募的非常不同的模式驱动的，这些差异最终是由温度和食物可获得性的区域差异造成的，并由实际的幼虫运输过程调节。因此，该项目将通过操纵性实地实验、实地采样、连接性估计和综合模拟来检验以下假设：1)在浮游幼虫净出口区域(北部GOM)，局部分散的物种主导动态，而在高定居和种群间广泛联系的区域(南部GOM)，浮游幼虫物种主导动态。2)浮游幼虫种群的定居密度由北向南递增，与食物可获得性的区域差异一致。3)不同地区的种群连通性差异很大，不同地区的自种或作为幼虫源与汇的程度不同；自种导致GM中部的种群动态相对局部化。4)种群连通性由物理运输过程驱动，并可通过将基本幼虫行为模型与循环模型相耦合来表示。在横跨约600公里的GOM的18个不同地点，调查将评估招募、食物可获得性和次生生产力的变化，实验将评估暴露在海浪中和庇护下的栖息地的群落过程。该项目将使用水文、海流剖面和幼虫垂直分布调查来收集幼虫/循环耦合模型的数据。将使用元素指纹对种群连接性进行建模和经验性评估(针对一个物种)。空间上明确的元社区模型将跨所有项目组成部分进行集成，并测试区域和本地过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.