Code, data, and results for Bacon et al. Land use types differ strongly in urban forest diversity, composition, and structure. Submitted to Landscape and Urban Planning.
As cities expand tree planting to promote benefits to residents, they require strong baseline knowledge on urban forest conditions. Public tree databases are often used to assess urban forest composition, structure and diversity, yet recent studies suggest trees on private land can differ in important ways from public trees, influencing urban forest benefits and resilience. We used a city-wide network of plots in Montreal, Canada, spanning multiple urban gradients to assess six private and public land use types (residential, public right-of-way, institutional, commercial, parks (excluding woodlands), vacant lots) and asked how urban forest composition and structure differed. Our study presents one of the most complete urban forest inventories for a large North American city, capturing the diversity, structure, and composition of trees across multiple land use types. We found strong differences in tree abundance, size, and diversity among land use types, reflecting contrasting management practices and planting histories. Hedges emerged as a dominant feature across all land use types – but most prominently on residential land – contributing a substantial proportion of trees, particularly Thuja occidentalis. Residential land and public rights-of-way supported the greatest tree abundance and species richness, while parks contained larger trees and greater basal area. Despite overlapping species, dominance patterns differed across land use types. Our work emphasizes that public inventories are insufficient to represent citywide urban forest composition and structure, and private green spaces must be considered to better understand the urban forest. It also reveals that overall, the urban forest is much more diverse than previously thought.
To access data only, raw data and metadata can be found in the input/ folder. The only exception is the Montreal Public Tree inventory, which can be found here, and the land use data from Observatoire Grand Montréal, which can be downloaded at this link