The Cost of Not Maintaining Trees: Findings and Recommendations from an International Symposium and Summit

Abstract

Urban trees are both an asset and a cost to municipalities. Past research has focused largely on the asset—quantifying and valuing the social, economic, and environmental benefits provided by trees in urban areas. Relatively fewer studies have focused on defining the appropriate level of tree care (costs or inputs) for efficiently maintaining tree health and structural integrity, and potential resulting liabilities. On 18–20 March 2015, the International Society of Arboriculture assembled a panel of research and industry experts for a research symposium and summit titled, The Costs of Not Maintaining Trees. In the weeks leading up to the summit, the Delphi technique was initiated to help build consensus on key research questions related to the economics of trees and their care. After three iterations of questions and discussion, the panel identified 14 research topics that were deemed “very important” or “important” by at least 12 of the 14 expert panelists (80% being a commonly used threshold for consensus). Results of this work are intended to help focus future research and funding efforts in arboriculture and urban forestry.