Statistical models for generating and analysing spatial meta-community food-webs

在这个项目中，我们的目标是进一步了解Meta食物网的结构和动力学。为此，我们将结合联合收割机数据分析的自然食物网，耦合斑块系统的数值模拟，营养斑块动力学模型的发展，组织在四个工作包：（1）分析的空间营养组织在自然Meta食物网。我们将开发强大的指数来表征空间食物网结构，探索空间的营养结构的缩放，并量化Meta食物网的时间变化。该分析将基于经验食物网数据集，但也将适用于非营养生态相互作用，以及其他自然系统中的网络网络。最后，这些算法将被集成到一个开放的、公开可用的R包中。(2)数值（ODE）模拟在大型网络的耦合补丁，研究空间不均匀性和时间扰动的作用，在元食物网的结构和动力学。首先，我们将研究核心卫星范围分布，物种分布的嵌套模式对斑块的影响，淬灭的空间不均匀性（例如，参数紊乱和显着补丁），食物网结构的空间梯度，斑块大小异质性的影响。其次，我们将解决时间方面的Meta食物网。我们将研究脉冲扰动的响应，在不同的补丁同步人口动态（莫兰效应）的相关干扰的作用，以及在空间和营养网络的小波动的传播。(3)通过随机的、顺序的定殖和灭绝事件的Meta食物网的群落组装。我们将在空间显式模型中数值研究斑块动力学，将以前的研究扩展到更现实，复杂的扩散网络。接下来，我们将开发空间隐式斑块动力学模型，描述每个物种或相互作用的斑块密度。最后，我们将扩展结构集合种群模型，将斑块大小分布和丰度分布，营养相互作用连接集合种群和人口动态模型。(4)我们将使用发达的营养集合种群框架来研究栖息地丧失和破碎化对Meta食物网结构的影响，如营养级的数量。我们将测试栖息地破碎化是否对较高营养水平产生强烈影响，从而增加基底物种的丰度（正破碎效应），以及这种效应是否会被较高营养水平物种的更大传播能力所缓解。

In this project we aim to further our understanding about the structure and dynamics of meta food-webs. For this effect we will combine data analysis of natural food-webs, numerical simulations in systems of coupled patches, and the development of trophic patch dynamics models, organized in four work packages: (1) Analysis of the spatio-trophic organization in natural meta food-webs. We will develop robust indices to characterize spatial food-web structure, explore the scaling of trophic structure with space, and quantify temporal changes in meta food-webs. The analysis will be based on empirical food-web data sets, but will also be applied to non-trophical ecological interactions, as well as to network-on-networks in other natural systems. Finally, the algorithms will be integrated into an open, publicly-available R-package. (2) Numeric (ODE) simulations in large networks of coupled patches to study the role of spatial inhomogeneities and temporal disturbances for the structure and dynamics in meta-food webs. First, we will investigate the influence of core-satellite range distributions, nested patterns of species distributions on patches, quenched spatial inhomogeneities (e.g., parameter disorder and salient patches), spatial gradients in food-web structure, and the influence of patch size heterogeneity. Second, we will address temporal aspects in meta food-webs. We will study the response to pulse-perturbations, the role of correlated disturbances at different patches to synchronize population dynamics (Moran effect), and the propagation of small fluctuations in the spatial and trophic network. (3) Community assembly of meta food-webs by stochastic, sequential colonization and extinction events. We will numerically study the patch dynamics in spatial explicit models, extending previous research to more realistic, complex dispersal networks. Next, we will develop spatially implicit patch dynamics models that describe the patch density for each species or interaction. Finally, we will extend structural metapopulation models, that incorporate patch size distributions and abundance distributions, for trophic interactions to link metapopulation and population dynamics models. (4) We will use the developed trophic metapopulation framework to study the influence of habitat loss and fragmentation for the structure of meta food-webs, such as the number of trophic levels. We will test whether habitat fragmentation has a strong influence on higher trophic levels and thereby increases the abundance of basal species (positive fragmentation effect), and whether this effect is mitigated by the larger dispersal capabilities of species at higher trophic levels.