Large herbivores transform plant-pollinator networks in an African savanna

Pollination by animals is a key ecosystem service1,2 and interactions between plants and their pollinators are a model system for the study of ecological networks3,4, yet plant-pollinator networks are typically studied in isolation from the broader ecosystems in which they are embedded. The plants visited by pollinators also interact with other consumer guilds that eat stems, leaves, fruits, or seeds. One such guild, large mammalian herbivores, are well-known ecosystem engineers5–7 and may have substantial impacts on plant-pollinator networks. Although moderate herbivory can sometimes promote plant diversity8, potentially benefiting pollinators, large herbivores might alternatively reduce resource availability for pollinators by consuming flowers9, reducing plant density10, and promoting somatic regrowth over reproduction11. The direction and magnitude of such effects may hinge on abiotic context—in particular, rainfall, which modulates the effects of ungulates on vegetation12. Using a ...

动物传粉是关键生态系统服务(ecosystem service)1,2，植物与其传粉者的种间互作是生态网络(ecological network)研究的经典模式系统(model system)3,4，但当前植物-传粉者网络(plant-pollinator network)的相关研究通常脱离其所处的更大尺度生态系统开展。传粉者造访的植物还会与其他取食茎、叶、果实或种子的消费者类群(consumer guilds)产生互作关系。其中一类消费者类群——大型哺乳动物食草动物(large mammalian herbivores)——是学界公认的生态系统工程师(ecosystem engineers)5–7，可对植物-传粉者网络产生显著影响。尽管适度食草作用(herbivory)有时可提升植物多样性8，进而可能惠及传粉者，但大型食草动物也可通过取食花朵9、降低植物种群密度10以及优先促进营养生长而非生殖生长11，压缩传粉者可利用的资源储量。此类效应的方向与强度可能取决于非生物环境因子，其中尤以降水最为关键：降水可调控有蹄类动物(ungulates)对植被的影响12。本研究使用……