Hidden similarities in the dynamics of a weakly synchronous marine metapopulation
Hidden similarities in the dynamics of a weakly synchronous marine metapopulation
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弱同步海洋集合种群动态中隐藏的相似性
DOI：
10.1073/pnas.1910964117
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
S. Munch
中科院分区：
文献类型：
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作者：
Tanya L. Rogers;S. Munch
意义我们预测和管理集合种群的能力取决于我们对其潜在种群动态的理解。当地动态和环境随机性的差异可导致独立的人口波动，但对人口管理和预测人口将如何应对环境变化具有极大不同的影响。量化局部动态中的异质性尤其具有挑战性，因为许多因素可能导致局部动态中的差异。以蓝蟹为例，我们提出了一种方法，可以区分不同的局部动态和由不同的环境条件驱动的相似的局部动态。这种方法可以帮助我们区分与人口轨迹无关的机制，并提供对人口动态空间结构的洞察。许多海洋物种的种群只有微弱的同步性，尽管通过幼虫扩散和暴露在同步的环境驱动因素中进行耦合。虽然这通常归因于观测噪声，但包括局部环境差异、空间可变动态和混沌在内的因素也可能减少或消除集合种群同步。为了区分空间可变的动力学和由空间可变的环境驱动的相似的动力学，我们应用了分层延迟嵌入。这种方法的一个独特的输出是“动态关联”，它量化种群内在动态中的相似性，而不管它们的丰度是否随着时间的推移而相关。我们将这些方法应用于美国大西洋沿岸的17个蓝蟹种群，发现它们的内在动态大致相似，尽管它们的数量在很大程度上是独立的波动。证据的份量表明，温度的纬度梯度，通过单峰响应曲线过滤，足以将螃蟹种群分离。由于单峰热表现在外温带中普遍存在，我们认为这可能是在许多海洋物种中远距离观察到的弱同步性的一般解释，尽管需要更多的研究来检验这一假说。
Significance Our ability to predict and manage metapopulations depends on our understanding of their underlying population dynamics. Differences in local dynamics and environmental stochasticity can result in independent population fluctuations but have vastly different implications for population management and predicting how populations will respond to environmental change. Quantifying heterogeneity in local dynamics is particularly challenging because many factors can contribute to differences in local dynamics. Using blue crabs as a case study, we present an approach which can differentiate dissimilar local dynamics from similar local dynamics driven by disparate environmental conditions. This methodology can help us differentiate among mechanisms that decorrelate population trajectories and provide insight into the spatial structure of population dynamics. Populations of many marine species are only weakly synchronous, despite coupling through larval dispersal and exposure to synchronous environmental drivers. Although this is often attributed to observation noise, factors including local environmental differences, spatially variable dynamics, and chaos might also reduce or eliminate metapopulation synchrony. To differentiate spatially variable dynamics from similar dynamics driven by spatially variable environments, we applied hierarchical delay embedding. A unique output of this approach, the “dynamic correlation,” quantifies similarity in intrinsic dynamics of populations, independently of whether their abundance is correlated through time. We applied these methods to 17 populations of blue crab (Callinectes sapidus) along the US Atlantic coast and found that their intrinsic dynamics were broadly similar despite largely independent fluctuations in abundance. The weight of evidence suggests that the latitudinal gradient in temperature, filtered through a unimodal response curve, is sufficient to decouple crab populations. As unimodal thermal performance is ubiquitous in ectotherms, we suggest that this may be a general explanation for the weak synchrony observed at large distances in many marine species, although additional studies are needed to test this hypothesis.