Biodiverse cities: the nursery industry, homeowners, and neighborhood differences drive urban tree composition

In arid and semi-arid regions, where few if any trees are native, city trees are largely human-planted. Societal factors such as resident preferences for tree traits, nursery offerings, and neighborhood characteristics are potentially key drivers of urban tree community composition and diversity, however they remain critically understudied. We investigated patterns of urban tree structure in residential neighborhoods of the Salt Lake Valley, Utah, combining biological variables, such as neighborhood and plant nursery tree species and trait composition, and sociological data comprised of resident surveys and U.S. Census data. We sampled nine neighborhoods that varied in household income and age of homes. We found more tree species were offered in locally-owned nurseries compared with mass merchandiser stores and yard trees at private residences were more diverse than public street trees in the same neighborhoods. There were significant differences among neighborhoods in street and yard t...