Cole Ella F, Long Peter R, Zelazowski Przemyslaw, Szulkin Marta, Sheldon Ben C
Department of Zoology Edward Grey Institute University of Oxford Oxford UK.
Department of Zoology Biodiversity Institute University of Oxford Oxford UK.
Ecol Evol. 2015 Oct 19;5(21):5057-74. doi: 10.1002/ece3.1745. eCollection 2015 Nov.
Population-level studies of how tit species (Parus spp.) track the changing phenology of their caterpillar food source have provided a model system allowing inference into how populations can adjust to changing climates, but are often limited because they implicitly assume all individuals experience similar environments. Ecologists are increasingly using satellite-derived data to quantify aspects of animals' environments, but so far studies examining phenology have generally done so at large spatial scales. Considering the scale at which individuals experience their environment is likely to be key if we are to understand the ecological and evolutionary processes acting on reproductive phenology within populations. Here, we use time series of satellite images, with a resolution of 240 m, to quantify spatial variation in vegetation green-up for a 385-ha mixed-deciduous woodland. Using data spanning 13 years, we demonstrate that annual population-level measures of the timing of peak abundance of winter moth larvae (Operophtera brumata) and the timing of egg laying in great tits (Parus major) and blue tits (Cyanistes caeruleus) is related to satellite-derived spring vegetation phenology. We go on to show that timing of local vegetation green-up significantly explained individual differences in tit reproductive phenology within the population, and that the degree of synchrony between bird and vegetation phenology showed marked spatial variation across the woodland. Areas of high oak tree (Quercus robur) and hazel (Corylus avellana) density showed the strongest match between remote-sensed vegetation phenology and reproductive phenology in both species. Marked within-population variation in the extent to which phenology of different trophic levels match suggests that more attention should be given to small-scale processes when exploring the causes and consequences of phenological matching. We discuss how use of remotely sensed data to study within-population variation could broaden the scale and scope of studies exploring phenological synchrony between organisms and their environment.
关于山雀物种（Parus spp.）如何追踪其毛虫食物来源物候变化的种群水平研究，提供了一个模型系统，有助于推断种群如何适应气候变化，但这类研究往往存在局限性，因为它们隐含地假设所有个体都经历相似的环境。生态学家越来越多地使用卫星数据来量化动物环境的各个方面，但到目前为止，研究物候的研究通常是在大空间尺度上进行的。如果我们要理解影响种群内繁殖物候的生态和进化过程，考虑个体体验其环境的尺度可能是关键。在这里，我们使用分辨率为240米的卫星图像时间序列，来量化一片385公顷的混交落叶林地植被返青的空间变化。利用跨越13年的数据，我们证明，冬季蛾幼虫（Operophtera brumata）数量峰值出现时间以及大山雀（Parus major）和蓝山雀（Cyanistes caeruleus）产卵时间的年度种群水平测量值，与卫星衍生的春季植被物候有关。我们进一步表明，当地植被返青时间显著解释了种群内山雀繁殖物候的个体差异，并且鸟类和植被物候之间的同步程度在林地中呈现出明显的空间变化。高橡树（Quercus robur）和榛树（Corylus avellana）密度区域显示，两种鸟类的遥感植被物候与繁殖物候之间的匹配度最强。不同营养级物候匹配程度在种群内存在显著差异，这表明在探索物候匹配的原因和后果时，应更多关注小尺度过程。我们讨论了如何利用遥感数据研究种群内变异，这可能会拓宽探索生物与其环境之间物候同步的研究规模和范围。
