Urban Tree Inventories in Canadian Municipalities

Municipal tree inventories support urban forest planning and management, while also providing data for research on urban forest structure and equity. We surveyed Canadian urban municipalities to assess the state, development, and use of municipal tree inventories and their associations with municipal, environmental, and institutional characteristics. Among 135 responding municipalities, 77% reported an existing or in-progress tree inventory. Inventories were predominantly field based, digitized, and focused on street and park trees. Remote sensing, including for canopy cover maps, was used by 47.6% of municipalities with inventories, most of whom also had field-based inventories. Tree location, species identification, diameter at breast height, and tree condition were the most commonly recorded metrics, aligning with the predominant use of inventories for tree planting and maintenance activities. More than one-fifth of municipalities with inventories reported that their inventories were used for only a single need or purpose. The presence of a tree inventory was positively associated with municipal land area and a dedicated urban forestry budget, while more advanced inventory states and broader data collection and use were generally associated with greater urban forestry budgets and staffing levels. Municipal size was also associated with several inventory outcomes, whereas environmental characteristics were less consistently associated. Contemporary best practices should emphasize digital data management, stable spatial references such as geographic coordinates, using accepted taxonomic nomenclature, and preservation of past inventory data to support long-term monitoring and interoperability.