Investigating the carbon sequestration and storage capacity of trees in a university campus environment

Abstract

Rising anthropogenic greenhouse gas emissions are well established as the main driver of climate change, which has led to concentrated global and regional efforts to mitigate emissions. At a localized level, individual institutions are likewise engaging in a variety of mitigation practices, helping to support broader frameworks. These mitigation practices can include managing and enhancing local carbon sinks to offset site-specific greenhouse gas production. In particular, urban forests have been a focus in recent literature for their capacity to sequester and store carbon. This study quantified the carbon sequestration and storage capacity of the urban forest located on Dalhousie University’s campuses in Halifax, Nova Scotia. Using an inventory of trees collected in the 2009-10 academic year, literature-derived growth rates were applied to approximate the current size of the campus trees. Carbon sequestration and storage values for individual trees were then estimated using i-Tree Eco v6 modelling software. The total annual sequestration rate was found to be less than 0.1% of Dalhousie’s annual greenhouse gas emissions, suggesting a considerable need to increase the campus urban forest’s capacity to act as a carbon sink. Additional relationships between carbon sequestration and characteristics such as diameter at breast height and species were also examined, suggesting that larger trees and species with rapid growth rates should be prioritized in maintaining the urban forest. This study is intended to be used as a baseline assessment of the on-campus urban forest carbon pool, from which future changes to the campus tree inventory can be made. Recommendations from this study may be used to inform updates to Dalhousie’s natural environment management policies and shape future development of the campus carbon sink.