Smith-Ramírez Cecilia, Ramos-Jiliberto Rodrigo, Valdovinos Fernanda S, Martínez Paula, Castillo Jessica A, Armesto Juan J
Instituto de Ecología y Biodiversidad (IEB), Facultad de Ciencias, Universidad de Chile, Santiago, Chile,
Oecologia. 2014 Sep;176(1):157-69. doi: 10.1007/s00442-014-3000-0. Epub 2014 Jul 8.
Long-term studies of plant-pollinator interactions are almost nonexistent in the scientific literature. The objective of the present study was to determine changes and trends in the pollinator assemblage of ulmo (Eucryphia cordifolia; Cunoniaceae), a canopy-emergent tree found in Chilean temperate rainforests. We assessed the temporal variability of the pollinator assemblage and identified possible modulators of the observed temporal shifts. We sampled insect visitors to the flowers of 16 individual trees of E. cordifolia during 10 consecutive flowering seasons (2000-2009), recording a total of 137 pollinator species with a mean number of species per year of 44. Only three pollinator species (2.2%) were recorded every year. Two bee species accounted for 50% of all insect visits to flowers. One bee species, Bombus dahlbomii (native), was dominant in one season, whereas Apis mellifera (exotic) dominated during the next season. These interannual shifts in population abundances presented first-order dynamics that were characterized by oscillations with a period of 2 years. Changes in the abundances of the dominant pollinators, as well as differences in temperature and precipitation during insect emergence and flowering, led to a nested temporal structure of pollinator composition. Furthermore, the abundances of less common pollinators were sensitive to the abundance of the dominant bee species and to monthly maximum temperatures and the average precipitation during spring and summer. Based on our results and those from other studies, we predict a decline in the numbers of Bombus dahlbomii and nondominant native pollinators in response to new exotic arrivals.
科学文献中几乎不存在对植物-传粉者相互作用的长期研究。本研究的目的是确定乌尔莫树（Eucryphia cordifolia；南康科）传粉者组合的变化和趋势，乌尔莫树是一种生长在智利温带雨林中的树冠层突出树木。我们评估了传粉者组合的时间变异性，并确定了观察到的时间变化的可能调节因素。我们在连续10个开花季节（2000 - 2009年）对16棵E. cordifolia个体树的花朵上的昆虫访客进行了采样，共记录了137种传粉者物种，每年的平均物种数为44种。每年仅记录到三种传粉者物种（2.2%）。两种蜜蜂物种占所有昆虫访花次数的50%。一种蜜蜂物种，本地的达尔氏熊蜂（Bombus dahlbomii）在一个季节占主导地位，而另一个季节则是外来的意大利蜜蜂（Apis mellifera）占主导。这些种群丰度的年际变化呈现出以2年为周期振荡的一阶动态。优势传粉者丰度的变化，以及昆虫出现和开花期间温度和降水的差异，导致了传粉者组成的嵌套时间结构。此外，较不常见传粉者的丰度对优势蜜蜂物种的丰度以及春季和夏季的月最高温度和平均降水量敏感。根据我们的研究结果以及其他研究的结果，我们预测达尔氏熊蜂和非优势本地传粉者的数量将因新的外来物种到来而减少。
