ADAPTATION OF I-TREE ECO TO NEW ZEALAND

Urban trees provide a range of benefits to humanity, known as ecosystem services. The US Forest Service developed a model known as i-Tree Eco for quantifying these benefits and applying dollar values to them. However, i-Tree Eco lacks species- and location-specific information for New Zealand (NZ). This study investigates the applicability and data requirements for using i-Tree Eco to quantify the ecosystem services of urban trees in Auckland, NZ. This included a case-study of 95 trees of 7 species in Wynyard Quarter. Auckland weather and air pollution data were successfully incorporated into i-Tree Eco, and it was found that while the model can currently be used for approximate quantifications, research into species-specific biomass, growth, and leaf area equations would improve the usefulness of the model by providing more certainty on the accuracy of results. Mature trees were found to have much higher rates of pollutant removal and carbon sequestration than immature trees. Valuations of pollutant removal were found to be incomplete, but results suggested a possible pollutant removal value of NZD $246/year total for the 95 trees, primarily from <10 micron particulate matter. Suggestions were made for future research to improve use of i-Tree Eco in NZ