Health and wellbeing benefits of urban forests in winter: a narrative review

Urban trees and green spaces, hereafter, urban forests, are known to contribute to human health and wellbeing. However, research has predominantly focused on warm seasons. To understand whether these benefits extend to winter months, when vegetation is dormant, we conducted a narrative review of the health outcomes associated with urban forests in winter in cities with cold climates. We synthesized findings from 21 studies originating from Asia, Europe and North America. The most studied health outcomes were mental health, physical activity and physiological relaxation, all showing a positive relationship with urban forest exposure. These finding appear similar to those observed in warmer seasons. However, more studies are needed, on a diversity of health outcomes, to draw more robust conclusions in this emerging research field. Future research on urban forests should therefore consider winter and the effect of seasonality to improve health and wellbeing of urban dwellers in all seasons.