Department of Biology, University of Massachusetts Dartmouth, Dartmouth, Massachusetts, USA.
Program in Bioinformatics and Computational Biology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA.
Conserv Biol. 2021 Oct;35(5):1519-1529. doi: 10.1111/cobi.13754. Epub 2021 May 16.
Understanding how anthropogenic disturbances affect plant-pollinator systems has important implications for the conservation of biodiversity and ecosystem functioning. Previous laboratory studies show that pesticides and pathogens, which have been implicated in the rapid global decline of pollinators over recent years, can impair behavioral processes needed for pollinators to adaptively exploit floral resources and effectively transfer pollen among plants. However, the potential for these sublethal stressor effects on pollinator-plant interactions at the individual level to scale up into changes to the dynamics of wild plant and pollinator populations at the system level remains unclear. We developed an empirically parameterized agent-based model of a bumblebee pollination system called SimBee to test for effects of stressor-induced decreases in the memory capacity and information processing speed of individual foragers on bee abundance (scenario 1), plant diversity (scenario 2), and bee-plant system stability (scenario 3) over 20 virtual seasons. Modeling of a simple pollination network of a bumblebee and four co-flowering bee-pollinated plant species indicated that bee decline and plant species extinction events could occur when only 25% of the forager population showed cognitive impairment. Higher percentages of impairment caused 50% bee loss in just five virtual seasons and system-wide extinction events in less than 20 virtual seasons under some conditions. Plant species extinctions occurred regardless of bee population size, indicating that stressor-induced changes to pollinator behavior alone could drive species loss from plant communities. These findings indicate that sublethal stressor effects on pollinator behavioral mechanisms, although seemingly insignificant at the level of individuals, have the cumulative potential in principle to degrade plant-pollinator species interactions at the system level. Our work highlights the importance of an agent-based modeling approach for the identification and mitigation of anthropogenic impacts on plant-pollinator systems.
了解人为干扰如何影响植物-传粉者系统，对于保护生物多样性和生态系统功能具有重要意义。先前的实验室研究表明，近年来与传粉者快速全球衰退有关的杀虫剂和病原体，会损害传粉者适应利用花卉资源和有效在植物间传递花粉所需的行为过程。然而，这些亚致死胁迫对个体水平上传粉者-植物相互作用的潜在影响，是否会扩大到系统水平上野生植物和传粉者种群动态的变化，尚不清楚。我们开发了一个基于个体的模拟蜜蜂授粉系统的经验参数化代理模型，称为 SimBee，以测试压力诱导的个体觅食者记忆容量和信息处理速度下降对蜜蜂丰度（情景 1）、植物多样性（情景 2）和蜜蜂-植物系统稳定性（情景 3）的影响，共 20 个虚拟季节。对蜜蜂和四种共开花传粉植物的简单授粉网络进行建模表明，当只有 25%的觅食者种群表现出认知障碍时，蜜蜂数量减少和植物物种灭绝事件就可能发生。在某些条件下，更高比例的认知障碍会导致在仅仅五个虚拟季节内蜜蜂损失 50%，并且在不到 20 个虚拟季节内系统范围的灭绝事件。植物物种灭绝发生与蜜蜂种群大小无关，表明仅由于传粉者行为的胁迫诱导变化就可能导致物种从植物群落中消失。这些发现表明，尽管在个体水平上，亚致死胁迫对传粉者行为机制的影响似乎微不足道，但从原则上讲，它们具有累积的潜力，可能会降低系统水平上的植物-传粉者物种相互作用。我们的工作强调了基于代理的建模方法对于识别和减轻人为对植物-传粉者系统影响的重要性。
