Abstract While cities are known as important habitats for wild bees, a conceptual understanding of how assemblages of wild bee species are shaped by urban environments is limited. We applied a functional approach to test how taxonomic and functional diversity within wild bee communities of urban grasslands, and traits of bee species, related to local habitat features (e.g., management, species richness, flower coverage) and characteristics of the surrounding urban matrix (e.g., urbanisation, isolation). Surprisingly, urbanisation was not related to any diversity measure. Yet, taxonomic and functional diversity in bee communities, and proportion of endangered bee species, responded negatively to the isolation of grasslands within the urban matrix—but positively to flower coverage. Urbanisation, previous restoration efforts and site type filtered the functional composition of bee communities in terms of species traits related to diet and nesting. Results substantiate the role of urban habitats for functionally diverse bee communities, including Red-Listed species, and indicate pathways towards enhancing habitat functions of urban grasslands for wild bees by (i) improving the connectivity of urban grassland patches within the urban matrix, and (ii) more locally by adjusting management to maintain flower coverage in grasslands. These approaches can support efforts to develop pollinator-friendly greenspaces within the urban green infrastructure.

中文翻译：

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城市草原上的野生蜜蜂：城市化、功能多样性和物种特征

摘要 虽然城市被认为是野生蜜蜂的重要栖息地，但对城市环境如何塑造野生蜜蜂物种组合的概念性理解是有限的。我们应用功能方法来测试城市草原野生蜜蜂群落内的分类和功能多样性，以及蜜蜂物种的特征与当地栖息地特征（例如，管理、物种丰富度、花卉覆盖率）和周围城市矩阵特征的关系。例如，城市化、隔离）。令人惊讶的是，城市化与任何多样性措施都无关。然而，蜜蜂群落的分类和功能多样性，以及濒临灭绝的蜜蜂物种的比例，对城市基质内草原的隔离产生负面影响，但对花卉覆盖产生积极影响。城市化，之前的恢复工作和场地类型根据与饮食和筑巢相关的物种特征过滤了蜜蜂群落的功能组成。结果证实了城市栖息地对功能多样化的蜜蜂群落（包括红色名录物种）的作用，并指出了通过（i）改善城市矩阵内城市草地斑块的连通性，以及（i）增强城市草地对野生蜜蜂的栖息地功能的途径，以及（ ii) 通过调整管理以保持草原的花卉覆盖率，从而更加本地化。这些方法可以支持在城市绿色基础设施内开发对授粉媒介友好的绿色空间的努力。包括红色名录物种，并指出通过 (i) 改善城市矩阵内城市草地斑块的连通性，以及 (ii) 通过调整管理以保持草地花卉覆盖率来提高城市草地对野蜂的栖息地功能的途径. 这些方法可以支持在城市绿色基础设施内开发对授粉媒介友好的绿色空间的努力。包括红色名录物种，并指出通过 (i) 改善城市矩阵内城市草地斑块的连通性，以及 (ii) 通过调整管理以保持草地花卉覆盖率来提高城市草地对野蜂的栖息地功能的途径. 这些方法可以支持在城市绿色基础设施内开发对授粉媒介友好的绿色空间的努力。