Quantifying the Effects of Climate on the Radial Growth Rates of Urban Trees in Toronto

Abstract

Despite the importance of trees to urban ecosystem services and citizens’ well-being, they are an understudied aspect of modern ecology. Although some studies have been conducted in other countries, no urban dendroclimatological work has been conducted in Canada. I investigated the impact of climate on urban tree growth, focusing on Toronto. I collected cores from five tree species: red oak, European linden, sugar maple, Norway maple, and Austrian pine, from street and park locations. I found a difference in environmental stress by location and by species, with street trees exhibiting negative correlations between summer temperature and growth. Norway maple and sugar maple were found to be particularly stressed by summer temperatures, with increases in negative growth-climate correlations in recent years, while red oak and linden were found to be less stressed by climate. An analysis of growth figures found high annual growth rates for both red oak and linden, and low annual growth for Norway maple and Austrian pine. This suggests that certain species may experience decreased growth rates in the coming decades due to climate change. The findings emphasize the need for attention to urban tree management in the face of changing climates, providing insights for urban forestry planning and conservation