A diverse and resilient urban forest is important for city-wide biodiversity and can maintain ecosystem services in the face of environmental changes. Tree diversity varies across cities, in response to factors such as urban form, public and private investment, and cultural preferences, often creating inequity in access to the urban forest and the services that it offers. Historically, public tree databases have been the basis for calculating urban forest diversity and ecosystem services, yet recent studies suggest that trees on private land can differ in important ways from public ones, greatly influencing the composition of the urban forest. Our project takes into account trees on public and private land, and asks how urban forest diversity and structure changes along gradients of socioeconomic status and urban built density. In 2023, we surveyed 34,000 individual trees of 400 different species across 25 neighbourhoods spanning the island of Montreal. We also incorporated community science into our sampling efforts, allowing us to connect with residents and collect fine-scale tree data from private spaces. We used the Canadian Index of Multiple Deprivation to measure the socioeconomic status of each neighbourhood, with our study sites spanning the full scale of the index, ensuring that we included a diverse range of communities in our sampling. Project results will help us better understand the interacting factors shaping urban forest diversity across the city, and how we can reduce inequity through both public and private tree management.
