International urban forestry sprung from roots associated with growth and maturation events of the International Society of Arboriculture. National urban forestry research of many countries was joined in 1974 under the Arboriculture and Urban Forestry Working Group of the International Union of Forest Research Organizations. Information ex­ change programs, research projects and their application, continuing urban forestry activities of IUFRO, those of ISA, and the FAO, U.N. have united the world community of arboriculture/urban forestry researchers and practitioners. Further organizational suggestions are offered to guide international urban forestry into a decade of global tree planting and conservation.