Dynamics of regime shifts in diverse and spatially structured marine communities

我提议的研究是在复杂的空间结构的海洋群落的政权转移的动力学。在生态状态下，政权转移是非线性的，通常是快速的变化。自然系统中的制度变迁涉及许多不同的物种，它们的丰度可以以非常不同的速度变化，并且可以在大的空间尺度上发挥作用。我的项目将专注于开发新的方法来理解空间和大小结构食物网的动态变化，以西北大西洋底栖食物网中底栖鱼类种群的崩溃为重点案例。我们将开发统计方法来模拟群落在制度转变期间的时空动态，以及大规模海洋系统的群落水平理论模型，以评估西北大西洋制度转变的不同潜在原因。我们的第一个目标将是开发统计工具来检测复杂和空间结构社区的变化。我的小组将测试和扩展我开发的一种统计方法，用于检测空间结构社区的变化，并将使用模拟和来自西北大西洋的长期数据来测试它在检测变化方面的有效性。我们将扩展该模型，包括系统发育相关性和功能性状数据，以更好地了解给定群落的哪些组成部分参与了转变。第二个目标将是开发空间结构的大小谱模型，以评估底栖鱼类崩溃的潜在原因，并测试社区水平和空间预测器在预测海洋系统状态变化方面的有效性。我们将开发纽芬兰和拉布拉多陆架的元群落规模-光谱模型，结合特定规模的人口统计学和分散率。我们将使用这些模型来测试底栖鱼崩溃的不同假设驱动因素是否能够在该生态系统中产生观察到的崩溃和恢复模式。我们的第三个目标将是发展关于鱼类和人类采集者运动的相互作用模式对渔业对制度变化的恢复力的影响的理论。我们将使用船只监测系统的长期记录来估计渔民对变化的捕捞条件的反应的运动模型，并利用这些结果将我之前的理论扩展到一个更广泛的理论中，即不同营养水平的非适应性或适应性运动的不同模式如何改变渔业生态系统对制度变化的易感程度。这项研究将为如何有效管理该地区渔业的决策提供信息，而所开发的统计和理论技术将更广泛地有助于研究复杂空间结构营养群落中物种丰度和分布的动态。

My proposed research is on the dynamics of regime shifts in complex spatially structured marine communities. Regime shifts are nonlinear, typically rapid, changes in an ecological state. Regime shifts in natural systems involve many different species whose abundances can change at very different rates, and can play out across large spatial scales. My program will focus on developing new approaches to understanding the dynamics of regime shifts in spatially and size-structured food-webs, using the collapse of the groundfish populations in the Northwest Atlantic benthic food web as a focal case. We will develop statistical approaches to model the spatiotemporal dynamics of communities during regime shifts and community-level theoretical models of large-scale marine systems to evaluate different potential causes of the Northwest Atlantic regime shift. Our first objective will be to develop statistical tools to detect shifts in complex and spatially structured communities. My group will test and extend a statistical method I developed to detect shifts in spatially structured communities, and will use simulations and long-term data from the Northwest Atlantic to test how effective it is for detecting shifts. We will extend the model to include phylogenetic relatedness and functional trait data to better understand what components of a given community are involved in a shift. The second objective will be to develop spatially structured size-spectrum models to evaluate potential causes of the groundfish collapse, and test the effectiveness of community-level and spatial predictors for forecasting regime shifts in marine systems. We will develop a metacommunity size-spectrum model of the Newfoundland and Labrador Shelf, incorporating size-specific demographic and dispersal rates. We will use these models to test whether different hypothesized drivers of the groundfish collapse are able to generate the observed patterns of collapse and recovery in this ecosystem. Our third objective will be to develop theory on the effects of interacting patterns of movement of fish and human harvesters on the resilience of fisheries to regime shifts. We will use long-term records from vessel monitoring systems to estimate movement models for fishermen's responses to changing fishing conditions, and use these results to extend my prior theory of the effects of interspecific variability in dispersal into a broader theory of how varying patterns of non-adaptive or adaptive movement at different trophic levels change how susceptible fished ecosystems are to regime change. This research will inform decisions on how to effectively manage fisheries in this region, and the statistical and theoretical techniques developed will contribute more broadly to research into the dynamics of species abundances and distributions in complex spatially structured trophic communities.