Manage for species or genotypes with wide moisture and temperature tolerances

Urban areas often experience even greater stress from heat, flooding, and drought than natural areas due to suboptimal growing conditions and high amounts of impervious cover. This additional stress, coupled with the uncertainty inherent in future climate projections, means that selecting for any particular future scenario may have some risk. A focus on species with large latitudinal ranges and wide tolerances may allow for better resilience.

Urban areas already contain a broad mixture of species that come from outside of the area. Because these species evolved in different climates, they will probably have very different tolerances to future climate conditions. In the urban landscape, fostering species transitions is less a question of whether to assist migration of species from other geographies; this is already a common occurrence. Instead, it is more about deciding when and where to incorporate species into forests and plantings in different habitats and land uses. These species could be nonnative taxa or species that are regionally native, that is, those from the same region but not currently growing at that particular location. In addition to increasing the climatic resilience of the urban landscape, urban forests could also facilitate the migration of species that will be favored under future climate to new habitats at or beyond the edges of their current range.