Geographical variation in the spatial synchrony of a forest-defoliating insect: isolation of environmental and spatial drivers
Geographical variation in the spatial synchrony of a forest-defoliating insect: isolation of environmental and spatial drivers
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DOI：
10.1098/rspb.2012.2373
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发表时间：
2013-02-22
影响因子：
4.7
通讯作者：
Liebhold, Andrew M.
中科院分区：
文献类型：
--
作者：
Haynes, Kyle J.;Bjornstad, Ottar N.;Liebhold, Andrew M.
尽管几乎每个分类单元中种群波动的空间同步性都普遍存在，但仍然很难理清其潜在机制，例如环境扰动和扩散。我们使用距离矩阵 (MRM) 的多元回归来统计划分可能同步吉普赛蛾动态的几个因素的重要性，吉普赛蛾是北美的一种入侵物种，在长距离（约 900 公里）上表现出部分同步的爆发。 MRM 考虑的因素是天气条件的同步性、空间邻近性和森林类型相似性。我们发现爆发同步最可能的驱动因素是同步降水。在考虑降水量后，邻近性对影响爆发同步性没有明显作用，这表明扩散不会驱动爆发同步性。由于之前的一项模型研究表明，天气可能会通过橡树肥大和以橡子为食的通才捕食者的同步来间接同步爆发，因此我们还研究了天气和接近度对橡子生产同步性的影响。正如我们发现的爆发同步性一样，橡树肥大的同步性随着降水的同步性而增加，尽管它也随着距离的接近而增加。我们得出的结论是，降水可以直接同步吉普赛蛾种群，如莫兰效应，或间接同步，通过对橡树肥大、通才捕食者或疾病的影响。
Despite the pervasiveness of spatial synchrony of population fluctuations in virtually every taxon, it remains difficult to disentangle its underlying mechanisms, such as environmental perturbations and dispersal. We used multiple regression of distance matrices (MRMs) to statistically partition the importance of several factors potentially synchronizing the dynamics of the gypsy moth, an invasive species in North America, exhibiting outbreaks that are partially synchronized over long distances (approx. 900 km). The factors considered in the MRM were synchrony in weather conditions, spatial proximity and forest-type similarity. We found that the most likely driver of outbreak synchrony is synchronous precipitation. Proximity played no apparent role in influencing outbreak synchrony after accounting for precipitation, suggesting dispersal does not drive outbreak synchrony. Because a previous modelling study indicated weather might indirectly synchronize outbreaks through synchronization of oak masting and generalist predators that feed upon acorns, we also examined the influence of weather and proximity on synchrony of acorn production. As we found for outbreak synchrony, synchrony in oak masting increased with synchrony in precipitation, though it also increased with proximity. We conclude that precipitation could synchronize gypsy moth populations directly, as in a Moran effect, or indirectly, through effects on oak masting, generalist predators or diseases.