Synchrony in metapopulations at multiple time scales: theory, experiments, and field data

研究背景：同一物种的种群在相距数百公里的地方经常一致或部分一致地波动，这种现象称为同步性。例如，英国蚜虫种类具有重要的经济意义，因为它们是一种主要的农业害虫，在短距离内80%的同步爆发，在200公里的距离内50%的同步爆发，这对大多数蚜虫物种来说是一个巨大的距离。事实上，同步性很普遍，在鸟类、旅鼠、鱼类（如鳕鱼）、人类病原体（如麻疹）、两栖动物和许多其他物种中都发现了同步性。许多表现出同步性的物种具有重要的保护、经济或健康意义。人口同步具有实际重要性的原因有几个。例如，同步的病虫害种群需要采取协调一致的应对措施。种群数量同步的濒危物种最终灭绝的危险更大，因为种群数量同时较低，可能会同时偶然灭绝。被开发的同步物种在许多市场的大范围内周期性地不可获得或较少可用。测量同步的方法只使用从1（完全同步）到-1（完全异步）的单个数字来描述两个种群之间的同步程度。这种方法很有用，但也有局限性：我们的结果表明，同步太复杂了，无法用一个数字来捕获。两个种群之间的同步主要发生在短时间尺度上，而在长时间尺度上几乎没有同步；或者在长时间尺度上，在短时间尺度上几乎没有同步；或者在任何时间尺度上。不同位置的环境变量之间的同步具有相同的复杂性。例如，伦敦和格拉斯哥的温度在年时间尺度（季节变化）和多年时间尺度（北大西洋涛动）上的上升和下降在很大程度上是一致的，但伦敦的短时间尺度（日）温度变化可能与格拉斯哥的温度变化不太相似。不同的同步时间尺度具有不同的生态和灭绝风险含义，并且可能对害虫的最佳控制策略具有不同的含义。此外，新的重要初步结果表明，环境同步性的时间尺度结构作为气候变化的一部分正在发生变化，并可能影响种群同步性，从而影响灭绝风险。研究目标：我们将利用大型时空数据库、新的理论和新的实验室实验来获得环境和种群同步性的广泛的时间尺度特定描述，并评估观测到的模式对气候变化、灭绝风险的影响，并推断导致该领域同步性的机制。应用：我们将提供有关新观察到的和以前未认识到的气候变化方面的信息，以及对其在保护和病虫害管理应用以及生态理解方面的总体重要性的全球评估。

Research context: Populations of the same species in locations hundreds of kilometers apart often fluctuate in unison or partly in unison, a phenomenon called synchrony. For instance, British aphid species, of economic importance because they are a major agricultural pest, outbreak 80% in synchrony over short distances and 50% in synchrony over distances of 200km, a huge distance for most aphid species. In fact, synchrony is widespread, and has been detected in birds, lemmings, fish such as cod, human pathogens such as measles, amphibians, and numerous other species. Many species exhibiting synchrony are of major conservation, economic, or health importance. Population synchrony has practical importance for several reasons. For instance, synchronized pest or disease populations require a coordinated response. An endangered species whose populations are synchronized is in accentuated danger of final extinction because populations are simultaneously low and might all go extinct by chance at once. An exploited synchronized species is periodically unavailable or less available across a wide area in many markets. Synchrony has been measured with methods that characterize the degree of synchrony between two populations only by a single number from 1 (perfect synchrony) down to -1 (perfect asynchrony). This approach is useful but limited: our results show synchrony is too complex to be captured with one number. Synchrony between two populations can occur mainly on short time scales, with little to no synchrony on long time scales; or on long time scales, with little or no synchrony on short time scales; or on any range of time scales. Synchrony between environmental variables in different locations has the same complexity. For instance, temperatures in London and Glasgow rise and fall largely together on annual time scales (seasonal variation) and multi-annual time scales (the North Atlantic Oscillation), but short-time-scale (day-to-day) temperature variation in London may resemble that in Glasgow much less. Different time scales of synchrony have different ecological and extinction-risk implications, and may have different implications for optimal control strategies for pests. In addition, new and important preliminary results show that the time-scale-specific structure of environmental synchrony is changing as part of climate change, and likely affects population synchrony, and thereby extinction risk. Research aims: We will use large spatio-temporal databases, new theory, and new lab experiments to obtain a broad time-scale-specific description of environmental and population synchrony, and to assess the implications of observed patterns for climate change, extinction risks, and inference of what mechanisms cause synchrony in the field. Applications: We will provide information about a newly observed and previously unrecognized aspect of climate change and a global assessment of its overarching importance for conservation and pest management applications and for ecological understanding.