Understanding the effects of urbanization on bee communities is essential for conservation and management programs for these pollinators. We investigated bee communities in two distinct land-use conditions in Mexico: one within the Bosque el Nixticuil-San Esteban-El Diente Natural Protected Area, which represents a conserved oak forest, and the other in a highly urbanized area in adjacent parks located approximately one kilometer from the conservation area in the Metropolitan Zone of Guadalajara with a population of 5.3 million. The objectives of the study were to 1) record the effects of urbanization on bee communities in terms of species richness, abundance and α and β diversity in an oak forest within a natural protected area and the adjacent urban area, and 2) identify the most susceptible bees and those that benefit from urbanization, and 3) to relate vegetation to bee communities. The results of the rarefaction analysis indicate that the protected natural area exhibited significantly higher richness and diversity than the urbanized area. Beta diversity analysis revealed a low species turnover, accompanied by a high rate of bee loss between conditions. A limited number of species demostrate an increase in abundance within urban areas, mainly Ceratina species, Augochlora smaragdina and Centris nitida. Furthermore, the richness of life history traits of bees was analysed. In all cases, the number of species decreased, with mainly non-eusocial, cavity or wood nesting, and polylectic feeding bees prevailing in the urban area. The richness and abundance of bees is related to the richness of plants, so it was expected to find more species and genera in the natural area. In conclusion, urbanization has a negative impact on the richness and diversity of bee communities, as well as on species composition.
