Assessing urban vacant land ecosystem services: Urban vacant land as green infrastructure in the City of Roanoke, Virginia

The research reported here quantifies the ecosystem services and values of vacant land using the City of Roanoke, Virginia as a study site. Aerial photo interpretation with ground-truthing was used to identify and catalog vacant parcels of land within the city limits and the results mapped using the i-Tree Canopy and i-Tree Eco models to define land cover classes and quantify ecosystem structure and services. An analysis of urban forest cover in Roanoke's vacant land reveals that this area has about 210,000 trees, with a tree cover of 30.6%. These trees store about 97,500 t of carbon, valued at $7.6 million. In addition, these trees remove about 2090 t of carbon (valued at $164,000), and about 83 t of air pollutants (valued at $916,000) every year, which is high relative to other land uses in Roanoke. Trees on vacant land in the city are estimated to reduce annual residential energy costs by $211,000 for the city's 97,000 residents. The structural value of the trees growing on vacant land is estimated at $169 million. Information on the structure and functions of urban forests on vacant land can be used to evaluate the contribution made by urban vacant land's green infrastructure to improving environmental quality. The methodology applied to assess ecosystem services in this study can also be used to assess ecosystem services of vacant land in other urban contexts.