Nilusha P. Y. Welegedara

Urban trees provide numerous ecosystem services (ESs) regardless of whether they grow on public or private lands. However, municipal tree protection policies have historically targeted public, city-owned trees while often neglecting trees on private property, which frequently comprise more than half of the urban forest canopy. Using the City of Edmonton, Canada, as a case study, this study demonstrates the necessity of protecting trees on private property in high-latitude winter cities based on the ESs they provide. We integrated tree characteristics derived from Light Detection and Ranging (LiDAR) data with the i-Tree Eco model to evaluate three primary ESs: gross carbon sequestration, avoided runoff, and air pollution removal. Results showed that private trees account for 60% of the tree canopy and provide significantly higher aggregate ESs and monetary value (p < 0.05) than public trees across mature neighborhoods. While public city-owned trees served as high-quality individual assets–characterized by larger diameters at breast height (DBH) and a higher proportion of deciduous trees–privately owned trees function as large-scale high-capacity collective assets, delivering 1.66 times greater total ESs due to their abundance. Given their substantial ecological contributions, monetary value, inherent growth constraints, and their vulnerability to infill development, urban trees in mature neighborhoods in high-latitude cities require an effective management strategy. Municipal policy frameworks in high-latitude winter cities should integrate top-down tree-protection bylaws with bottom-up community stewardship initiatives to safeguard forest canopy across both public and private lands.

High-latitude regions are witnessing unprecedented wildfires and accelerated warming. This study explored wildfire patterns and land changes within the high-latitude Indigenous Tłı̨chǫ territory in the Northwest Territories, Canada. It used the Two-Eyed Seeing approach, which combines Western science, or Scientific Ecological Knowledge (SEK), with Indigenous knowledge, or Traditional Ecological Knowledge (TEK). This method integrated Earth observation data with insights from Tłı̨chǫ Elders and officials. We analyzed spatiotemporal variations in burned areas, land surface temperature (LST), albedo, snow cover, soil moisture, and land-cover types. A listening and storytelling session with community Elders provided an in-depth Indigenous perspective. Our findings indicate a concerning shift in wildfire activity on Tłı̨chǫ land, primarily driven by the interplay between climate change and land-cover changes. Land-cover estimates over the past fifteen years indicate that nearly half of the forested areas on Tłı̨chǫ-owned land have been converted to other land-cover types, with shrublands increasing twofold and grasslands expanding tenfold. We observed significant increases in spring and summer LSTs (p < 0.05), alongside decreases in precipitation and snow cover (p < 0.05), consistent with the Elders’ observations. The decline in topsoil moisture, coupled with rising temperatures, has triggered a positive feedback loop in forested areas, intensifying future wildfire risk. The study’s implications extend beyond the Tłı̨chǫ territory, suggesting a broader significance for climate resilience and Indigenous stewardship. It highlights the significance of place-based, integrated research for understanding complex wildfire behavior and land-cover transformations. The study indicates that the Two-Eyed Seeing approach, which weaves local Indigenous knowledge with quantitative Earth observations, not only improves analytical precision but also provides a collaborative framework for developing targeted strategies to mitigate the effects of increasingly severe fire regimes and land-cover changes.