Urban forestry practitioners and managers face mounting challenges in sustaining tree canopy amid rising temperatures, constrained water resources, and limited municipal budgets. While broad canopy targets are often emphasized, these metrics oversimplify the complexity of urban ecosystems and miss critical nuances that can inform better planning and policy decisions. This presentation highlights recent findings that bridge science, practice, and policy, revealing new insights into the dual role of tree canopy in reducing household water use and improving thermal comfort.
Recent research from Dr. McHale’s lab highlights the importance of studying urban heat at scales that align with human experiences, addressing the limitations of low-resolution, satellite-derived, thermal imagery. The team has shown a clear, linear relationship between canopy cover and mean radiant temperature, with increasing canopy—even beyond the “magical” 30 percent metric—consistently enhancing outdoor thermal comfort. At the parcel scale, their findings reveal critical design factors influencing heat and water use. Smaller residential parcels, for example, consume more water due to neighborhood norms, homeowners’ associations, and design choices. Furthermore, xeriscaping and traditional lawns exhibit distinct tradeoffs between heat mitigation and water savings, particularly during hot, dry summers, while the orientation of landscapes challenges the conventional “west is best” belief perpetuated by i-Tree models. The team’s work also underscores the multifunctional value of trees in transportation corridors, demonstrating how they contribute to thermal comfort in ways that go beyond providing shade. Collectively, these insights emphasize the need for tailored, actionable strategies that reflect the lived experiences of urban residents and the specific dynamics of their environments.
Equally important is the role of partnerships between cities, universities, and industry in addressing these challenges. Drawing from collaborations in Canada’s Okanagan region, this presentation showcases how such partnerships enable cutting-edge science to inform urban forestry practices and policy. These collaborations not only advance the practical application of new tools but also empower cities to implement cost-effective solutions during times of reduced budgets. By co-producing knowledge, fostering trust, and leveraging shared goals, academia, practitioners, and policymakers can amplify the impacts of nature-based solutions to address shared climate adaptation challenges.