RUI Collaborative Research: Spatial Realism in the Mussel Bed Disturbance Paradigm

我们对物理干扰如何塑造种群和群落结构的理解，很大程度上归功于对贻贝床中波浪产生的间隙形成的实地研究。先前的研究将贻贝床描述为一个非平衡系统，其中的干扰在空间上是不可预测的，会产生贻贝覆盖和间隙的随机拼凑。该项目将测试另一种观点的假设和预测——扰动显示出可预测的景观模式，这种模式不仅取决于外部强迫（波应力）的空间分布，还取决于决定聚集结构的生物过程。具体来说，空间变化的贻贝生产力（招募和生长）、生理压力和捕食相互作用，在贻贝覆盖结构中产生景观格局。贻贝层的某些区域发展成直接附着在岩石上的单层，以抵抗干扰。其他区域以多层结构发展，当非常深的时候，浅层贻贝只能附着在邻近的贻贝上，而不是岩石表面，并导致内部贻贝只能微弱地附着在岩石上或彼此之间，有利于传播干扰。因此，间隙形成和恢复的空间格局是一个统一的景观过程。该项目的实地工作重点是使用一些创新的采样方法，在不列颠哥伦比亚省巴克利湾的10个贻贝床上建立一个详细的GIS数据库。每个站点的GIS数据层包括波浪力、地形（潮汐高度、坡度和坡向）、贻贝尺寸结构、贻贝床厚度、分层的差异以及逐层分层的特定尺寸附着强度。GIS插值和回归分析将用于首先检查假设景观过程的假设，然后测试有关干扰发生和恢复的空间模式的具体预测。最后，受控的野外实验将验证不同贻贝床结构对干扰的抵抗、程度和恢复的不同这一关键命题。智力优势：景观扰动假说包含了几个不同于该系统中先前扰动概念的过程：稳态（平衡）结构影响水动力应力引发扰动的可能性，以及一旦引发扰动是否会传播。因此，平衡过程决定了扰动过程的基本特征。干扰在概率范围内是可预测的，干扰的景观模式在很大程度上反映了基础物种的生物学特征。这种扰动范式的重构可能适用于各种受扰动影响的分层生态系统（例如生物膜、珊瑚礁、森林）。更广泛的影响：该项目形成了少数民族服务机构（加州州立大学洛杉矶分校），一个综合性大学，一个独特的海洋空间分析中心（加州州立大学蒙特利湾）和一级研究机构（加州大学洛杉矶分校）之间的联盟。合作伙伴有相当多的指导和外联支持系统可供利用。该项目为加州州立大学洛杉矶分校的学生创建了一个共同指导计划，提供海洋生态系统空间分析的深入介绍，无与伦比的实地研究经验，并接触到博士学位授予机构的研究实验室，包括潜在的博士顾问。计划在三个校区和实地场地班菲尔德海洋科学中心举办许多教育丰富和培训活动。该项目将扩大代表性不足的少数民族对西海岸生物海洋学的参与，并在这方面提供独特的资源。对公众和K-12教师的额外宣传将通过COSEE-West完成。

Our understanding of how physical disturbance shapes the structure of populations and communities owes much to field studies of wave-generated gap formation in mussel beds. Prior studies depict mussel beds as a non-equilibrium system, in which disturbance is spatially unpredictable, generating a random patchwork of mussel cover and gaps. This project will test assumptions and predictions of an alternative view -- that disturbance shows predictable landscape patterns that depend not merely on spatial distribution of external forcing (wave stress) but also on biological processes determining the structure of the aggregation. Specifically, spatially varying mussel productivity (recruitment and growth), physiological stress, and predation interact to produce landscape patterns in the structure of the mussel cover. Certain regions of the mussel bed develop as mono-layers attached directly to the rock, resisting disturbance. Other regions develop in multi-layered configurations that when very deep force superficial mussels to attach solely to adjacent mussels instead of the rock surface, and cause interior mussels to only weakly attach to either rock or one another, favoring propagating disturbances. Therefore, spatial patterns of gap formation and recovery emerge from a unified landscape process.Field work for this project emphasizes construction of a detailed GIS database using some innovative sampling methods applied to 10 mussel bed sites in Barkley Sound, British Columbia. GIS data layers for each site include wave force, topography (tidal height, slope, and aspect), mussel size structure, mussel bed thickness, differentiation of layering, and size-specific attachment strengths stratified by layer. GIS interpolations and regression analyses will be used to first examine assumptions of the hypothetical landscape process and then test specific predictions regarding spatial patterns in the occurrence of disturbance and recovery. Finally, controlled field experiments will test the key proposition that different mussel bed structures cause different resistance to-, extent of-, and recovery from disturbance.Intellectual Merit: The landscape disturbance hypothesis includes several processes that differ from previous conceptualizations of disturbance in this system: steady state (equilibrium) structures influence the likelihood that hydrodynamic stresses initiate a disturbance and whether once initiated the disturbance will propagate. Thus, equilibrium processes condition essential features of the disturbance process. Disturbance is predictable within probabilistic limits, and the landscape patterns of disturbance reflect in considerable measure the biological characteristics of a foundation species. This reframing of the disturbance paradigm may apply to a diverse array of layered ecosystems subject to perturbations (e.g. biofilms, coral reefs, forests).Broader Impacts: The project forms an alliance among a Minority Serving Institution (Cal State LA), a comprehensive university with a unique center for marine spatial analysis (Cal State Monterey Bay) and a Tier 1 Research Institution (UCLA). The partners have considerable mentoring and outreach support systems to draw upon. The project creates a co- mentoring program for Cal State LA students, providing an intensive introduction to spatial analysis of marine ecosystems, an unmatched field research experience, and exposure to research labs of a PhD granting institution, including potential PhD advisors. Numerous educational enrichment and training activities are planned for the three campuses and the field venue, Bamfield Marine Sciences Centre. The project will broaden participation of underrepresented minorities in biological oceanography on the West Coast, and provide a unique resource in that regard. Additional outreach to the public and K-12 teachers will be done through COSEE-West.