Identification of Municipal Policies That Influence the Distribution of Green Cover across Metropolitan Regions

Nature’s services provided by green cover are important to environmental conditions in cities and their ability to adapt to climate change. Researchers using geospatial technologies have dramatically increased the spatial and temporal resolution of knowledge about the distribution of tree and shrub cover in cities. Much of the current research on tree cover in cities has concentrated on individual preferences and associations between socioeconomic characteristics and environmental conditions. To complement existing research and provide planners with the practical tools they need to maintain the benefits of urban nature, this study focuses on the public policy factors that influence tree and other green cover at the lot and neighbourhood scales, concentrating on single family neighbourhoods. Green cover is classified using an object-oriented method with high spatial-resolution aerial imagery and GIS techniques. Landscape and property information were extracted from Los Angeles County Assessor Office files at a parcel scale for 20 cities in Los Angeles County. The extracted variables included lot size, floor-area ratio, residential landscape standards, tree protection ordinances, and street tree programs and were used along with average temperature and rainfall information in multiple regression models to explain the distribution and character of green cover across different neighbourhoods.