Vatka Emma, Orell Markku, Rytkönen Seppo
Department of Ecology, Faculty of Science, University of Oulu, P.O. Box 3000, FI-90014, Oulu, Finland.
Glob Chang Biol. 2016 Apr;22(4):1585-94. doi: 10.1111/gcb.13144. Epub 2016 Feb 9.
Phenological shifts and associated changes in the temporal match between trophic levels have been a major focus of the study of ecological consequences of climate change. Previously, the food peak has been thought to respond as an entity to warming temperatures. However, food peak architecture, that is, timings and abundances of prey species and the level of synchrony between them, determines the timing and shape of the food peak. We demonstrate this with a case example of three passerine prey species and their predator. We explored temporal trends in the timing, height, width, and peakedness of prey availabilities and explained their variation with food peak architecture and ambient temperatures of prebreeding and breeding seasons. We found a temporal match between the predator's breeding schedule and food availability. Temporal trends in the timing of the food peak or in the synchrony between the prey species were not found. However, the food peak has become wider and more peaked over time. With more peaked food availabilities, predator's breeding success will depend more on the temporal match between its breeding schedule and the food peak, ultimately affecting the timing of breeding in the predator population. The height and width of the food peak depended on the abundances and breeding season lengths of individual prey species and their reciprocal synchronies. Peakednesses of separate prey species' availability distributions alone explained the peakedness of the food peak. Timing and quantity of food production were associated with temperatures of various time periods with variable relevance in different prey species. Alternating abundances of early and late breeding prey species caused high annual fluctuation in the timing of the food peak. Interestingly, the food peak may become later even when prey species' schedules are advanced. Climate warming can thus produce unexpected changes in the food availabilities, intervening in trophic interactions.
物候变化以及营养级之间时间匹配的相关变化一直是气候变化生态后果研究的主要焦点。此前，食物高峰被认为是一个整体对气温升高做出反应。然而，食物高峰结构，即猎物物种的时间和丰度以及它们之间的同步程度，决定了食物高峰的时间和形态。我们以三种食虫鸣禽猎物物种及其捕食者为例进行了说明。我们探究了猎物可获得性在时间、高度、宽度和峰值方面的时间趋势，并用食物高峰结构以及繁殖前期和繁殖期的环境温度来解释它们的变化。我们发现捕食者的繁殖时间表与食物可获得性之间存在时间匹配。未发现食物高峰时间或猎物物种之间同步性的时间趋势。然而，随着时间的推移，食物高峰变得更宽且峰值更高。随着食物可获得性峰值更高，捕食者的繁殖成功率将更多地取决于其繁殖时间表与食物高峰之间的时间匹配，最终影响捕食者种群的繁殖时间。食物高峰的高度和宽度取决于单个猎物物种的丰度和繁殖季节长度以及它们相互之间的同步性。单独的猎物物种可获得性分布的峰值就能解释食物高峰的峰值。食物生产的时间和数量与不同时间段的温度相关，在不同猎物物种中的相关性各不相同。早繁殖和晚繁殖猎物物种的丰度交替导致食物高峰时间出现较大的年度波动。有趣的是，即使猎物物种的时间表提前，食物高峰可能也会推迟。因此，气候变暖会在食物可获得性方面产生意想不到的变化，进而干预营养级间的相互作用。
