With the rapid urbanization worldwide and ever-increasing impacts of human activities since at least 200 years ago, we are now facing a harsh situation of our biosphere. Building a global-level network model on ecological systems is of great importance, which would be able to provide us predictive and quantitative responses to human activities, leading to viable suggestions to policymakers. In this paper, we propose a multi-layer model for the global ecological network, where a number of local networks are connected via long-range interactions associated with migrant species, which can be induced by human activities or natural migration of wildlife, and each local network is generated by a trophic-level-based stochastic model. Predator–prey dynamics is described by a networked Lotka–Volterra model that accounts for the self-suppression effects on basal species, and the negative feedback loops. Impacts of human activities are modeled by investigating the quantitative changes of biodiversity under certain protecting strategies. We reveal that the global ecological network is organized in a clustered small-world manner, with in-degree distribution more heterogeneous than out-degree distribution. Protecting endangered species, popular preys and predicted-to-be-extinct species is more effective than randomly selected species or influential predators. Protecting after entering the fast extinction stage is more effective than at the beginning for some high trophic level species.

中文翻译：

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建模和保护全球生态网络

至少自 200 年前以来，随着全球范围内的快速城市化和人类活动的影响不断增加，我们现在面临着我们的生物圈的严峻形势。建立一个全球层面的生态系统网络模型非常重要，它能够为我们提供对人类活动的预测性和定量反应，从而为政策制定者提供可行的建议。在本文中，我们提出了一个全球生态网络的多层模型，其中多个局部网络通过与迁徙物种相关的长期相互作用连接起来，迁徙物种可以由人类活动或野生动物的自然迁徙引起，并且每个本地网络由基于营养级的随机模型生成。捕食者-猎物动力学由网络 Lotka-Volterra 模型描述，该模型解释了对基础物种的自我抑制效应和负反馈回路。通过调查某些保护策略下生物多样性的数量变化来模拟人类活动的影响。我们揭示了全球生态网络以集群的小世界方式组织，入度分布比出度分布更异质。保护濒临灭绝的物种、受欢迎的猎物和预计将灭绝的物种比随机选择的物种或有影响力的捕食者更有效。对于一些高营养级物种，进入快速灭绝阶段后的保护比开始时更有效。通过调查某些保护策略下生物多样性的数量变化来模拟人类活动的影响。我们揭示了全球生态网络以集群的小世界方式组织，入度分布比出度分布更异质。保护濒临灭绝的物种、受欢迎的猎物和预计将灭绝的物种比随机选择的物种或有影响力的捕食者更有效。对于一些高营养级物种，进入快速灭绝阶段后的保护比开始时更有效。通过调查某些保护策略下生物多样性的数量变化来模拟人类活动的影响。我们揭示了全球生态网络以集群的小世界方式组织，入度分布比出度分布更异质。保护濒临灭绝的物种、受欢迎的猎物和预计将灭绝的物种比随机选择的物种或有影响力的捕食者更有效。对于一些高营养级物种，进入快速灭绝阶段后的保护比开始时更有效。保护濒临灭绝的物种、受欢迎的猎物和预计将灭绝的物种比随机选择的物种或有影响力的捕食者更有效。对于一些高营养级物种，进入快速灭绝阶段后的保护比开始时更有效。保护濒临灭绝的物种、受欢迎的猎物和预计将灭绝的物种比随机选择的物种或有影响力的捕食者更有效。对于一些高营养级物种，进入快速灭绝阶段后的保护比开始时更有效。