Spatial prioritization for urban Biodiversity Quality using biotope maps and expert opinion

•We used a combination of community attributes to measure urban Biodiversity Quality.•We introduce a protocol for spatial prioritization of urban Biodiversity Quality.•Expert evaluations and pre-existing spatial data were used in the protocol.•Priority mapping helps planners and developers to avoid biodiversity loss.•The method is easy to replicate but requires spatial data and expert knowledge. Spatial prioritization can produce useful information about biodiversity values from urban areas. However, its typical focus on (endangered) species distributions assumes a rather restricted approach to urban biodiversity. In 2006, Feest suggested that five attributes of species assemblages more holistically describe the so called “Biodiversity Quality” of an area: species richness, biomass, population density, evenness, and rarity. Here we apply these attributes in spatial prioritization for urban biodiversity, across ten taxonomic groups: vascular plants, polypores, fungi (other than polypores), birds, bats, mammals (other than bats), herpetofauna, butterflies, hymenoptera, and beetles. In addition, we introduce two more attributes relevant for urban biodiversity conservation: support for specialist species and regional representativeness of the species assemblages. First, spatial data about local urban biotopes was acquired. For each taxon, the capacity of each urban biotope to support the seven introduced attributes of Biodiversity Quality was evaluated via expert elicitation. Expert opinion was then translated into a spatial analysis implemented with the Zonation software. Different anthropogenic, semi-natural, and natural habitats, such as herb-rich forests, lakeshores, open wastelands, fortifications, and botanical gardens, were identified as important for urban Biodiversity Quality. To minimize negative impact on biodiversity, future construction and development should be directed to built-up areas and agricultural fields. Our conception of urban biodiversity lies in between species- and habitat/ecosystem -based analyses and offers a more comprehensive perception of urban biodiversity than a focus on species distributions only, which facilitates the planning of ecologically sustainable cities and biodiverse urban green infrastructure.