Dynamics of regime shifts in diverse and spatially structured marine communities

我建议的研究是在复杂的空间结构的海洋群落的政权转变的动力学。制度变迁是一种非线性的，通常是快速的，生态状态的变化。自然系统中的状态变化涉及许多不同的物种，其丰度可以以非常不同的速率变化，并且可以在大的空间尺度上发挥作用。我的计划将侧重于开发新的方法来理解政权的动态变化在空间和大小结构的食物网，使用西北大西洋底栖食物网的底栖鱼类种群的崩溃作为焦点案例。我们将开发统计方法来模拟社区的时空动态在政权转移和大型海洋系统的社区级理论模型，以评估西北大西洋政权转移的不同潜在原因。我们的第一个目标将是开发统计工具，以检测复杂和空间结构的社区的变化。我的团队将测试和扩展我开发的一种统计方法，以检测空间结构社区的变化，并将使用来自西北大西洋的模拟和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，以包括系统发育相关性和功能性状数据，以更好地了解特定社区的哪些组成部分参与了转变。第二个目标将是建立空间结构尺寸谱模型，以评估底栖鱼崩溃的潜在原因，并测试社区一级和空间预测因子在预测海洋系统状况变化方面的效力。我们将开发一个变性尺寸谱模型的纽芬兰和拉布拉多大陆架，纳入特定尺寸的人口和扩散率。我们将使用这些模型来测试是否不同的假设驱动程序的底栖鱼崩溃能够产生观察到的模式崩溃和恢复在这个生态系统。我们的第三个目标将是发展理论的相互作用的移动模式的鱼类和人类收割机的渔业制度转变的弹性的影响。我们将使用长期的记录从船舶监测系统来估计运动模型渔民的反应不断变化的捕鱼条件，并使用这些结果来扩展我以前的理论种间变异的影响扩散到一个更广泛的理论如何不同的模式，在不同的营养水平的非适应性或适应性运动改变如何容易捕捞生态系统制度的变化。这项研究将为如何有效管理该地区渔业的决策提供信息，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的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.