Stability and evolution of networks on networks

网络上网络的稳定性和演进

• 批准号: 216500708
• 负责人: Professorin Dr. Barbara Drossel
• 金额: --
• 依托单位: Arbeitsgruppe Theorie komplexer Systeme
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/216500708?language=en
• 关键词: Stability; evolution; networks

The project investigates how structure, stability, and dynamics of spatially extended food webs depend on the arrangement of and the coupling between the different patches, on the heterogeneity of the patches, on the local dynamics, and on the addition of new species. To this purpose, models for metacommunities of up to 60 species on 60 patches coupled by migration will be generated and investigated. Four work packages are planned: (1) We will investigate how the heterogeneity of the patches (in terms of different mortality or different amount of resources) and the type of migration (stochastic or continuous) affect the suvrival of species and the local and global diversity. We will generate allometrically scaled food webs and initialize them with random initial biomasses. Evaluations will be done with stochastic and continuous migration. (2) We will use the generalized modelling approach, which is based on a linear stability analysis of a suitably scaled system, in order to evaluate the linear stabilty, the variability (i.e., the global oscillation of the populations) and the occurrence of critical tranisitions in metacommunities. Variability will be determined based on the phases of the entries of the eigenvector to the largest eigenvalues. Critical transitions will be identified based on saddle node bifurcations, and they will be studied further in other projects of the RU. (3) The body-mass based evolutionary food web model developped during the first funding period will be investigated on several patches coupled by migration in order to study the influence of spatial structure and migration strength on the survival of species and on the local and global diversity. We will investigate the case of stochastic migration as well as the case of continuous migration. (4) In order to simulated many species on many patches, we will simplify the evolutionary model such that it does not contain explicit population dynamics. The rule for deciding which species survive and die out, will be based on estimates of biomass flows and competition, and will also take into account that specialists have higher attack rates. The emergent properties of the metacommunity will be investigated, and local and global diversities and other structural signatures shall be conpared to empirical systems and to the colonization-extinction models studied in other projects of this RU.

该项目研究了空间扩展食物网的结构，稳定性和动态如何取决于不同斑块之间的排列和耦合，斑块的异质性，局部动态以及新物种的增加。为此，将生成并研究60个斑块上多达60个物种的元群落模型，并结合迁移。（1）研究斑块的异质性（不同的死亡率或不同的资源量）和迁移类型（随机或连续）对物种生存率、局部和全球多样性的影响。我们将生成异速生长的食物网，并使用随机的初始生物量对其进行初始化。将通过随机和连续迁移进行评价。(2)我们将使用广义建模方法，该方法基于适当比例系统的线性稳定性分析，以评估线性稳定性、可变性（即，种群的全球振荡）以及元群落中关键转变的发生。将基于特征向量到最大特征值的条目的相位来确定可变性。关键的转变将确定鞍节点分叉的基础上，他们将在RU的其他项目进一步研究。(3)将对第一个供资期间开发的基于体重的进化食物网模型进行调查，以研究空间结构和迁移强度对物种生存以及对地方和全球多样性的影响。我们将研究随机迁移的情况以及连续迁移的情况。(4)为了模拟许多斑块上的许多物种，我们将简化进化模型，使其不包含显式的种群动态。决定哪些物种生存和灭绝的规则将基于对生物量流动和竞争的估计，并将考虑到专家的攻击率较高。将调查的metacompatibility的紧急属性，和本地和全球的dibrillation和其他结构的签名应considerable到经验系统和本RU的其他项目中研究的殖民灭绝模型。