Despite advances in metapopulation theory, recent studies have emphasized the difficulty in understanding and accurately predicting dynamics in nature. We address this knowledge gap by coupling 4 years of population data for the freshwater zooplankter Daphnia pulex, inhabiting 38 newly established ponds in Upstate New York, with (i) a spatially explicit stochastic model and (ii) a deterministic model where we have averaged the spatial dependencies. By modifying the identity of ponds stocked/removed in our model, we examine the effects of network structure on metapopulation dynamics and local occupancy patterns. From these modeling exercises, we show that the centrality of ponds (stocked or removed) has contrasting effects on metapopulation persistence when selecting ponds to initially stock versus preserve. The pond network was not robust to the removal of centrally located ponds as the simulated removal of these ponds resulted in rapid collapse of the metapopulation. However, when initially founding a metapopulation, the location of patches did not influence occupancy dynamics. Because stochastic simulations can be computationally expensive, we also introduce a quantity for use in a simple differential equation model that encompasses all spatial information in a single variable. Using this quantity, we show how the output of our simple differential equation model matched the quasi-steady state of the stochastic simulations in networks characterized by high connectivity. The method we use is general enough to be applied in other systems and can provide insights for habitat conservation and restoration efforts including how network structure can drive spatiotemporal metapopulation dynamics.

中文翻译：

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斑块集中度影响小型淡水池塘的种群动态

尽管后代种群理论取得了进步，但最近的研究强调了理解和准确预测自然界动态的困难。我们通过耦合淡水浮游动物水蚤（Daphnia pulex）的4年人口数据来解决这一知识鸿沟在纽约州北部的38个新建池塘中居住，（i）空间显式随机模型和（ii）确定性模型，其中我们对空间依赖性进行了平均。通过修改模型中放养/移出池塘的身份，我们研究了网络结构对种群动态和局部居住模式的影响。从这些模拟练习，我们表明，池塘的中心（库存或删除）已选择池塘时，最初的股票与保存在集合种群持久的效果对比。池塘网络对中心池塘的去除并不稳健，因为对这些池塘的模拟去除导致了种群的迅速崩溃。但是，当最初发现一个种群时，斑块的位置并不影响占用动态。由于随机模拟的计算量很大，因此我们还引入了一个数量，用于简单的微分方程模型，该模型将所有空间信息都包含在一个变量中。使用此数量，我们展示了简单微分方程模型的输出如何与以高连通性为特征的网络中的随机模拟的准稳态相匹配。我们使用的方法足够通用，可以在其他系统中使用，并且可以为栖息地的保护和恢复工作提供见解，包括网络结构如何驱动时空分布种群动态。我们展示了简单微分方程模型的输出如何与以高连通性为特征的网络中的随机模拟的准稳态相匹配。我们使用的方法足够通用，可以在其他系统中使用，并且可以为栖息地的保护和恢复工作提供见解，包括网络结构如何驱动时空分布种群动态。我们展示了简单微分方程模型的输出如何与以高连通性为特征的网络中的随机模拟的准稳态相匹配。我们使用的方法足够通用，可以在其他系统中应用，并且可以为栖息地的保护和恢复工作提供见解，包括网络结构如何驱动时空多种群动态。