Pollination in a new climate: Assessing the potential influence of flower temperature variation on insect pollinator behaviour
Pollination in a new climate: Assessing the potential influence of flower temperature variation on insect pollinator behaviour
复制标题
新气候下的授粉：评估花温变化对昆虫授粉行为的潜在影响
作者：
M. Shrestha;Jair E. Garcia;Zoe Bukovac;A. Dorin;A. Dyer
气候变化有可能增强或破坏生物系统，但目前，人们对生物的可塑性如何促进适应局部气候变化知之甚少。蜜蜂-花朵关系是一个典型的信号-接收系统，它可能为在这样的情况下生态相互作用的复杂性提供重要的见解。例如，几项关于蜜蜂温度偏好的研究表明，蜜蜂更喜欢在较低的环境温度下从花朵中采集温暖的花蜜，但在环境温度超过30摄氏度时，它们会将自己的偏好转向较凉爽的花朵。我们使用温度传感器热探头测量了澳大利亚大陆南部地区30种植物的室外花朵温度，以了解不同物种如何根据环境温度的变化调节花瓣温度，并潜在地影响蜜蜂对开花植物的决策。我们发现，花瓣温度对环境温度的变化有不同的响应方式：相对于环境温度线性增加或降低，以非线性方式动态变化，或随环境条件变化。例如，我们对环境温度和花瓣温度之间的差异(ΔT)以及环境温度的研究表明，沙枣和远志之间存在非线性关系，似乎适合蜜蜂的温度偏好。一些物种的温度曲线似乎表明，它们没有降温机制。因此，在环境温度增加到30°C以上的变化的气候条件下，这些物种对蜜蜂传粉者的吸引力可能会降低。当考虑到昆虫传粉者介导的选择时，这可能会对该物种不利。然而，我们没有发现蜜蜂用花的视觉特征来识别近距离的花，如颜色或形状，是花朵温度的直接调节器的证据。我们也找不到任何与系统发育历史和温度调节有关的明确联系。然而，绘制我们在澳大利亚大陆上测试的花分布图表明，潜在的聚集表明不同的花反应可能构成对当地条件的适应。我们的研究提出了一个框架，用于模拟气候变化和花朵温度对局部和全球尺度上的花朵授粉动态的潜在影响。
Climate change has the potential to enhance or disrupt biological systems, but currently, little is known about how organism plasticity may facilitate adaptation to localised climate variation. The bee-flower relationship is an exemplar signal-receiver system that may provide important insights into the complexity of ecological interactions in situations like this. For example, several studies on bee temperature preferences show that bees prefer to collect warm nectar from flowers at low ambient temperatures, but switch their preferences to cooler flowers at ambient temperatures above about 30° C. We used temperature sensor thermal probes to measure the temperature of outdoor flowers of 30 plant species in the Southern regions of the Australian mainland, to understand how different species could modulate petal temperature in response to changes in ambient temperature and, potentially, influence the decision-making of bees in the flowering plant’s favour. We found that flower petal temperatures respond in different ways to changing ambient temperature: linearly increasing or decreasing relative to the ambient temperature, dynamically changing in a non-linear manner, or varying their temperature along with the ambient conditions. For example, our investigation of the difference between ambient temperature and petal temperature (ΔT), and ambient temperature, revealed a non-linear relationship for Erysimum linifolium and Polygala grandiflora that seems suited to bee temperature preferences. The temperature profiles of species like Hibertia vestita and H. obtusifolia appear to indicate that they do not have a cooling mechanism. These species may therefore be less attractive to bee pollinators in changing climatic conditions with ambient temperatures increasingly above 30° C. This may be to the species’ detriment when insect-pollinator mediated selection is considered. However, we found no evidence that flower visual characteristics used by bees to identify flowers at close range, such as colour or shape, were straightforward modulators of floral temperature. We could not identify any clear link to phylogenetic history and temperature modulation either. Mapping our test flower distribution on the Australian continent however, indicates a potential clustering that suggests different flower responses may constitute adaptations to local conditions. Our study proposes a framework for modelling the potential effects of climate change and floral temperature on flower pollination dynamics at local and global scales.