PDF(Pubmed)
Abstract：
Pollinating insects are decreasing worldwide due to various environmental stresses (so-called pollinator crisis), raising concerns that plant productivity could be undermined in natural and agricultural ecosystems. To date, however, few studies have reported a concurrent decline in both pollinators and plants, and little is known about when a \"plant crisis\" occurs. Here, we propose that anthropogenic environmental stresses on pollinating insects (e.g. climate change, habitat loss, and pesticide usage) can negatively affect herbivorous insects (e.g., pollinator larvae and crop pests) as well, and effects of pollinator declines may be masked by positive effects of herbivore declines. To test the idea, we theoretically investigated plant population dynamics mediated by two insect groups: one representing a pollinator that is mutualistic at the adult stage but antagonistic at the larval stage, and the other representing a non-structured pest herbivore. Our model revealed that environmental stresses (increasing insect mortality) can have counterintuitive effects on plants. Nonetheless, plant abundance generally decreases with decreasing pollinator abundance, especially when plant populations grow slowly without pollinators, when pollinators are effective mutualists, or when pollinators are susceptible to environmental stresses. These findings offer a theoretical basis for assessing the pollinator crisis for biodiversity conservation and agricultural management.
摘要：
由于各种环境压力（所谓的传粉者危机），全球传粉昆虫正在减少，人们担心自然和农业生态系统中的植物生产力可能会受到损害。迄今为止,然而,很少有研究报道传粉媒介和植物同时下降，人们对“植物危机”何时发生知之甚少。这里,我们建议人为环境压力对授粉昆虫(例如气候变化，栖息地丧失,和杀虫剂的使用)会对草食性昆虫产生负面影响(例如，传粉幼虫和作物害虫)，传粉者减少的影响可能被草食动物减少的积极影响所掩盖。为了测试这个想法，我们从理论上研究了由两个昆虫群体介导的植物种群动态:一个代表传粉媒介，在成虫阶段是相互的，但在幼虫阶段是拮抗的，另一个代表非结构化害虫草食动物。我们的模型表明，环境压力（增加昆虫死亡率）可能对植物产生违反直觉的影响。尽管如此，植物丰度通常随着传粉媒介丰度的降低而降低，尤其是当植物种群在没有授粉媒介的情况下生长缓慢时，当传粉者是有效的互助者时，或者当传粉者容易受到环境压力时。这些发现为评估生物多样性保护和农业管理的传粉者危机提供了理论基础。
