A comparison of neighborhood characteristics related to canopy cover, stem density and species richness in an urban forest

Urban forest patterns within cities are primarily governed by social factors such as neighborhood characteristics, municipal policy, and individual residents. While a growing body of literature has examined the influence of such factors on tree canopy extent, less attention has been given to other aspects of the urban forest, including tree density and species diversity patterns. Comparing the correlates of canopy cover to other measures of the urban forest is useful for understanding the complex factors shaping urban forest conditions, and can help guide future studies considering the causes of such patterns. This paper explores two inter-related questions: (1) are there differences in the neighborhood correlates of canopy cover, stem density, and species richness? and (2) is canopy cover alone a sufficient representation of the urban forest to understand the ways social factors are related to broader patterns of trees? The questions were addressed through statistical analyses to identify neighborhood socioeconomic and urban form variables correlated with plot-level measures of the three tree variables. The study area includes residential land within Peel Region, which is located in the Greater Toronto Area (Ontario, Canada). We found that significant correlates are different among the three urban forest variables examined, with neighborhood factors having the weakest relationship to species diversity. The results suggest that the underlying mechanisms associated with canopy cover, stem density and species richness patterns vary, and that future studies should consider multiple tree metrics when exploring social correlates to better understand how and why the urban forest varies across a city.

► Significant correlates vary between different measures of the urban forest.
► Canopy cover is correlated with development age; tree density and richness are not.
► Neighborhood characteristics are not strongly related to species richness.