Identifying priority urban green areas for biodiversity conservation and equitable recreational accessibility using spatial prioritization

• Spatial prioritization for biodiversity and equitable accessibility of green areas. • Mismatch between single-objective priorities for biodiversity and accessibility. • Spatial prioritization can assist mitigating trade-offs in urban planning. Sustainable urban planning requires identification of priority areas for people and biodiversity that should not be lost due to urban growth. We present a spatial prioritization of urban green areas of the Helsinki metropolitan area, Finland, to identify those areas that are needed to preserve both urban biodiversity and the equitable provision of recreational green spaces among all city districts. The suitability of urban areas for the Biodiversity Quality attributes of ten taxonomic groups were used as a surrogate for biodiversity, and the proximity of green areas to each city district while accounting for realistic travel times for accessibility. Overall, there was a great mismatch between areas identified as most important for supporting biodiversity vs. those important for equitable access to recreation. Based on a surrogacy analysis, accessibility was a better surrogate for biodiversity than vice versa. When urban green spaces were prioritized over both biodiversity and accessibility, higher contributions to both objectives could be achieved. A balanced prioritization that considers both objectives and includes currently protected areas can be used to inform land-use planning about the most important unprotected green areas from the biodiversity and recreational equitability perspectives. Low-priority areas would be preferred for new urban development to minimize impacts to biodiversity and recreation. Moreover, overlays between biodiversity, accessibility, and ecosystem sensitivities to anthropogenic disturbances inform local-scale planning and green area management. Systematic analyses, such as spatial prioritization, can facilitate transparent and unbiased urban planning, which accounts for the spatial complementarity of areas important to both people and biodiversity.