Urban trees for carbon sequestration

Abstract

Urban trees represent potential carbon (C) sequestration pools. To examine theC sequestration of an urban tree, factors such as C storage in biomass, avoided Cemissions from energy conservation, and C emissions associated with tree maintenance and decomposition must be considered. Maximum tree sizes, lifespans, growth rates, and tolerances to urban stress were used to create four metrics for comparing the relative C sequestration potential of 145 popular urban tree species. These analyses show that differences in the relative urban tree C index (RUTCI) may be related to phylogenetic characteristics. In particular, longer-lived species with higher tolerances to urban stresses and higher wood densities appear to have the highest potential for sequestering C. Current urban tree populations are comprised of species with moderate ratings according to the RUTCI, suggesting that C sequestration potential of urban forests can be improved.