Laboratório de Interações Multitróficas e Biodiversidade, Departamento de Biologia Animal, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP, 13083-970, Brazil.
Institute of Biological Sciences, Universidade Federal do Pará, Belém, PA, Brazil.
Oecologia. 2020 Mar;192(3):745-753. doi: 10.1007/s00442-020-04612-0. Epub 2020 Feb 3.
Biotic and abiotic factors may individually or interactively disrupt plant-pollinator interactions, influencing plant fitness. Although variations in temperature and precipitation are expected to modify the overall impact of predators on plant-pollinator interactions, few empirical studies have assessed if these weather conditions influence anti-predator behaviors and how this context-dependent response may cascade down to plant fitness. To answer this question, we manipulated predation risk (using artificial spiders) in different years to investigate how natural variation in temperature and precipitation may affect diversity (richness and composition) and behavioral (visitation) responses of flower-visiting insects to predation risk, and how these effects influence plant fitness. Our findings indicate that predation risk and an increase in precipitation independently reduced plant fitness (i.e., seed set) by decreasing flower visitation. Predation risk reduced pollinator visitation and richness, and altered species composition of pollinators. Additionally, an increase in precipitation was associated with lower flower visitation and pollinator richness but did not alter pollinator species composition. However, maximum daily temperature did not affect any component of the pollinator assemblage or plant fitness. Our results indicate that biotic and abiotic drivers have different impacts on pollinator behavior and diversity with consequences for plant fitness components. Even small variation in precipitation conditions promotes complex and substantial cascading effects on plants by affecting both pollinator communities and the outcome of plant-pollinator interactions. Tropical communities are expected to be highly susceptible to climatic changes, and these changes may have drastic consequences for biotic interactions in the tropics.
生物和非生物因素可能单独或相互作用破坏植物-传粉者的相互作用，影响植物的适应性。尽管温度和降水的变化预计会改变捕食者对植物-传粉者相互作用的总体影响，但很少有实证研究评估这些天气条件是否会影响植物的抗捕食行为，以及这种依赖于环境的反应如何向下游影响植物的适应性。为了回答这个问题，我们在不同年份操纵捕食风险（使用人工蜘蛛），以研究温度和降水的自然变化如何影响访花昆虫对捕食风险的多样性（丰富度和组成）和行为（访问）反应，以及这些影响如何影响植物的适应性。我们的研究结果表明，捕食风险和降水增加独立地通过减少花访问来降低植物的适应性（即种子设置）。捕食风险降低了传粉者的访问和丰富度，并改变了传粉者的物种组成。此外，降水增加与较低的花访问和传粉者丰富度相关，但没有改变传粉者的物种组成。然而，最高日温度对任何传粉者组合或植物适应性的组成部分都没有影响。我们的研究结果表明，生物和非生物驱动因素对传粉者行为和多样性有不同的影响，对植物适应性的组成部分有影响。即使降水条件有微小的变化，也会通过影响传粉者群落和植物-传粉者相互作用的结果，对植物产生复杂而实质性的级联效应。热带群落预计对气候变化高度敏感，这些变化可能对热带地区的生物相互作用产生巨大影响。
