RT Journal Article SR Electronic T1 Contracting for Urban Tree Maintenance JF Arboriculture & Urban Forestry (AUF) FD International Society of Arboriculture SP 16 OP 17 DO 10.48044/jauf.1991.004 VO 17 IS 1 A1 William B. Lough YR 1991 UL http://auf.isa-arbor.com/content/17/1/16.abstract AB New York City has significantly increased the contracting out of municipal forestry work in the 80’s. Unit Price contracts were initially used but the Time and Material format has been implemented as being more efficient, less costly and allowing a greater degree of management flexibility.