The Rocky Mountain Biological Laboratory, Post Office Box 519, Crested Butte, Colorado, 81224, USA.
Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL, 32306, USA.
Ecol Lett. 2017 Dec;20(12):1507-1515. doi: 10.1111/ele.12854. Epub 2017 Sep 28.
Climate change can influence consumer populations both directly, by affecting survival and reproduction, and indirectly, by altering resources. However, little is known about the relative importance of direct and indirect effects, particularly for species important to ecosystem functioning, like pollinators. We used structural equation modelling to test the importance of direct and indirect (via floral resources) climate effects on the interannual abundance of three subalpine bumble bee species. In addition, we used long-term data to examine how climate and floral resources have changed over time. Over 8 years, bee abundances were driven primarily by the indirect effects of climate on the temporal distribution of floral resources. Over 43 years, aspects of floral phenology changed in ways that indicate species-specific effects on bees. Our study suggests that climate-driven alterations in floral resource phenology can play a critical role in governing bee population responses to global change.
气候变化可以直接影响生物的生存和繁殖，也可以通过改变资源间接地影响生物种群。然而，人们对直接和间接影响的相对重要性知之甚少，特别是对于那些对生态系统功能很重要的物种，如传粉媒介。我们使用结构方程模型来测试直接和间接（通过花卉资源）气候效应对三种高山蜂种群数量的年际变化的重要性。此外，我们还利用长期数据来研究气候和花卉资源随时间的变化情况。在 8 年的时间里，蜜蜂的丰度主要受到气候对花卉资源时间分布的间接影响。在 43 年的时间里，花卉物候的各个方面都发生了变化，这表明对蜜蜂有特定的影响。我们的研究表明，气候驱动的花卉资源物候变化可能在控制蜜蜂种群对全球变化的响应方面发挥关键作用。
