OOS 34-3 - Greening minimums? Examining urban forestry pathways that support environmental justice in three Los Angeles County cities

Cities are sites of intense competition over how land is allocated. Land use policy dictates boundary conditions in land allocation. For example, parking minimums are a land use policy that requires developed sites to provide space to store cars with the number of parking spaces depending on the square footage of buildings or the number of bedrooms. Space competition and most existing policy requirements favor or mandate built land covers (buildings + pavement). This is especially the case in low-income neighborhoods with small lot sizes or areas within neighborhoods where housing is typically more affordable (e.g., multi-family zones). Green space requirements are not common and often greening only then exists where it fits into the leftover spaces not allocated to other land covers. Thus, inequitable distributions in urban greenspace such as tree canopy cover can been seen as the direct response of policy setting conditions that disfavor greenspace. As part of developing their urban forest management plans, we are examining through case study three small cities (populations: 53,644, 52,506, and 23,726) in the county of Los Angeles, California, USA with median household incomes and urban tree canopy covers of 80% or less of the statewide values. In these three cities, we find the intersection of historic public right of way infrastructure priorities and land use policies act to limit tree canopy cover and create the systemic mechanisms for the creation of inequality in urban tree canopy cover. We further compared existing street and parcel conditions to modeled design outcomes based on existing policy requirements and under proposed policy innovations that mandate greening minimums. In conclusion, greening minimums are a potential policy tool for creating space in high density urban landscapes and can function as a systems lever to address underlying mechanisms of inequitable distributions of urban tree canopy cover.