Table 1.

Definitions of terms related to ecosystem services and disservices in urban forests, as used in this manuscript. Notably, some of these terms are contested (Konijnendijk et al. 2006; Fisher et al. 2009) and may continue to evolve

Term	Definition	Citation(s)
Ecosystem services	“[T]he benefits that people derive from functioning ecosystems”	Costanza et al. (2017), although definitions are debated (Fisher et al. 2009)
Ecosystem disservices	“[E]cosystem generated functions, processes and attributes that result in perceived or actual negative impacts on human wellbeing”	Shackleton et al. (2016), see also Lyytimäki and Sipilä (2009) and Vaz et al. (2017)
Management costs	Direct budgetary expenses for urban forestry stakeholders to plant, maintain, and remove trees, including costs for materials (e.g., trees, equipment) and paid labor (e.g., arborists); management costs are distinct from ecosystem disservices in that disservices are not on stakeholders’ accounting ledgers	This manuscript, but see Vogt et al. (2015)
Negative synergy	A lose–lose situation that involves a mutual increase in ecosystem disservices, with an implied reduction in ecosystem services; also called “jointly negative” outcomes; more broadly speaking, negative synergies are situations in which the holistic impact is worse than each individual component	This manuscript, but see Jackson and Mathews (2011) and Persha et al. (2011)
Positive synergy	“[A] win–win situation that involves a mutual improvement of two ecosystem services”, with an implied reduction in disservices; more broadly speaking, positive synergies are situations in which the holistic impact is greater, and more beneficial, than each individual component	Felipe-Lucia et al. (2015) and Jackson and Mathews (2011)
Tradeoff	Often refers to a “[s]ituation in which land use or management actions increase the provision of one ecosystem service and decrease the provision of another”, but could also refer to a situation in which an ecosystem service increases while disservice(s) also increase (i.e. win-lose)	Felipe-Lucia et al. (2015)
Tree risk management	The application of policies, procedures, and practices to identify, evaluate, mitigate, monitor, and communicate risk regarding trees in urban areas, including assessments of likelihood of tree failure (i.e., tree or limbs falling) and consequences of failure (i.e., injury, property damage, utility damage)	Dunster et al. (2013) and Klein et al. (2019)
Urban greening	“[O]rganized or semi-organized efforts to introduce, conserve, or maintain outdoor vegetation in urban areas”	Eisenman et al. (2019)
Urban forest	The system of trees in cities, suburbs, towns, and other urbanized areas, including public and private lands, spanning street trees and residential yards as well as highly designed and natural parks	Miller et al. (2015)
Urban forestry	The management and study of trees and forest resources in urbanized areas; some definitions explicitly call out management objectives for environmental, social and economic benefits; the practice of urban forestry is closely related to urban greening, but urban forestry has distinct disciplinary traditions and professional spheres	Konijnendijk et al. (2006)