Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
Department of Life Sciences, Achva Academic College, Arugot, 7980400, Israel.
Ecol Appl. 2017 Dec;27(8):2342-2358. doi: 10.1002/eap.1612. Epub 2017 Oct 23.
Spatial synchrony plays an important role in dictating the dynamics of spatial and stage-structured populations. Here we argue that, unlike the Moran effect where spatial synchrony is driven by exogenous factors, spatial correlation in intrinsic/local-scale processes can affect the level of spatial synchrony among distinct sub-populations, and therefore the persistence of the entire population. To explore this mechanism, we modelled the consequences of spatial heterogeneity in aquatic habitat quality, and that of temporal variation in local extinction probability, on the persistence of stage-structured mosquito populations. As a model system, we used two widely distributed mosquito species, Aedes albopictus and Culex pipiens, both key vectors of a range of infectious diseases. Spatial heterogeneity in aquatic habitat quality led to increased population persistence, and this pattern was more pronounced at intermediate dispersal rates, and in the long-dispersing species (C. pipiens). The highest regional persistence was obtained at high dispersal rates. This is probably because dispersal, in our model, did not carry any additional costs. Population persistence of both species was negatively correlated with increased temporal variation in local extinction probability. These differences were stronger in the short-dispersing species (A. albopictus), especially at intermediate dispersal rates. The dispersal of A. albopictus adults in each time step was limited to the nearest habitat patches, weakening the positive effect of spatial heterogeneity in aquatic habitat quality on population persistence. In contrast, C. pipiens adults could disperse into more remote sub-populations, resulting in much higher recolonization rates. Hence, the negative effect of temporal variation in local extinction probability on patch occupancy disappeared at intermediate dispersal rates. We suggest that effectively controlling these two mosquito species requires making few spatially synchronized control efforts (i.e., generating high temporal variation in local extinction probability), rather than many asynchronized local control efforts. Finally, our model can be easily fitted to other organisms characterized by complex life cycles, and it can be also used to examine alternative scenarios, including the effect of spatial configuration of local habitat patches and dispersal kernel shape on population persistence.
空间同步在决定空间和阶段结构种群的动态方面起着重要作用。在这里，我们认为，与由外源性因素驱动的 Moran 效应不同，内在/本地尺度过程中的空间相关性会影响不同亚种群之间的空间同步水平，从而影响整个种群的持久性。为了探索这种机制，我们模拟了水生栖息地质量的空间异质性和局部灭绝概率的时间变化对阶段结构蚊子种群持久性的影响。作为模型系统，我们使用了两种广泛分布的蚊子，白纹伊蚊和致倦库蚊，它们都是一系列传染病的关键传播媒介。水生栖息地质量的空间异质性导致种群持久性增加，在中等扩散率下，以及在长距离扩散的物种（C. pipiens）中，这种模式更为明显。在高扩散率下，区域持久性最高。这可能是因为在我们的模型中，扩散没有带来任何额外的成本。两种物种的种群持久性与局部灭绝概率的时间变化增加呈负相关。在短距离扩散的物种（A. albopictus）中，这种差异更为强烈，尤其是在中等扩散率下。每个时间步中 A. albopictus 成虫的扩散范围仅限于最近的栖息地斑块，这削弱了水生栖息地质量空间异质性对种群持久性的正向影响。相比之下，C. pipiens 成虫可以扩散到更远的亚种群，从而导致更高的再殖民化率。因此，在中等扩散率下，局部灭绝概率的时间变化对斑块占有率的负效应消失。我们认为，有效控制这两种蚊子需要进行少量的空间同步控制工作（即产生局部灭绝概率的高时间变化），而不是许多非同步的局部控制工作。最后，我们的模型可以很容易地应用于具有复杂生活史的其他生物，并可用于检验替代情景，包括局部栖息地斑块的空间配置和扩散核形状对种群持久性的影响。
