Functional homogenization of flower visitor communities with urbanization

Land-use intensification and resulting habitat loss are put forward as the main causes of flower visitor decline. However, the impact of urbanization, the prime driver of land-use intensification in Europe, is poorly studied. In particular, our understanding of whether and how it affects the composition and functioning of flower visitor assemblages is scant, yet required to cope with increasing urbanization worldwide. Here, we use a nation-wide dataset of plant-flower visitor (Coleoptera, Diptera, Hymenoptera, Lepidoptera) interactions sampled by citizen scientists following a standardized protocol to assess macroecological changes in richness and composition of flower visitor communities with urbanization. We measured the community composition by quantifying the relative occurrence of generalist and specialist flower visitors based on their specialisation on flowering plant families. We show that urbanization is associated with reduced flower visitor richness and a shift in community c...土地利用集约化及其引发的生境丧失，被认为是访花昆虫种群衰退的主要诱因。然而，作为欧洲土地利用集约化的核心驱动因素，城市化的相关影响却鲜有研究。具体而言，目前我们对城市化是否以及如何影响访花昆虫类群的组成与功能仍知之甚少，但这一认知缺口亟需填补，以应对全球范围内日益加剧的城市化进程。 本研究依托一套由公民科学家依照标准化采样方案获取的全国性植物-访花昆虫（鞘翅目Coleoptera、双翅目Diptera、膜翅目Hymenoptera、鳞翅目Lepidoptera）互作数据集，探究城市化驱动下访花昆虫群落的丰富度与组成的宏生态学变化。本研究通过基于访花昆虫对显花植物科的特化程度，量化广食性与专食性访花昆虫的相对占比，以此表征群落组成。研究结果表明，城市化与访花昆虫丰富度降低以及群落组成的转变相关……