The consequences of environmental disturbance and management are difficult to quantify for spatially structured populations because changes in one location carry through to other areas as a result of species movement. We develop a metric, G, for measuring the contribution of a habitat or pathway to network-wide population growth rate in the face of environmental change. This metric is different from other contribution metrics, as it quantifies effects of modifying vital rates for habitats and pathways in perturbation experiments. Perturbation treatments may range from small degradation or enhancement to complete habitat or pathway removal. We demonstrate the metric using a simple metapopulation example and a case study of eastern monarch butterflies. For the monarch case study, the magnitude of environmental change influences the ordering of node contribution. We find that habitats within which all individuals reside during one season are the most important to short-term network growth under complete removal scenarios, whereas the central breeding region contributes most to population growth over all but the strongest disturbances. The metric G provides for more efficient management interventions that proactively mitigate impacts of expected disturbances to spatially structured populations.

中文翻译：

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量化生境和途径对面对环境变化的空间结构化人口的贡献。

对于空间结构种群而言，环境扰动和管理的后果难以量化，因为物种移动会导致一个位置的变化传播到其他区域。我们制定了指标G，用于衡量面对环境变化时栖息地或途径对全网络人口增长率的贡献。此指标不同于其他贡献指标，因为它量化了扰动实验中修改栖息地和途径生命率的影响。扰动处理的范围可能从轻微的退化或增强到完整的栖息地或通路清除。我们使用一个简单的种群示例和东部帝王蝶的案例研究来证明该指标。对于君主案例研究，环境变化的幅度会影响节点贡献的顺序。我们发现，在完全清除的情况下，一个人在一个季节内所处的栖息地对于短期网络的增长最为重要，而除了最强烈的干扰外，中部繁殖区对人口增长的贡献最大。指标G提供了更有效的管理干预措施，可以主动减轻预期干扰对空间结构人口的影响。