The reorganization of the UPLB College of Forestry into the College of Forestry and Natural Resources on 25 June 1998 necessitated the merger of its two academic units – the Department of Forest Resources Management and the Department of Silviculture and Forest Influences into the present Institute of Renewable Natural Resources (IRNR).

The Institute is composed of seven co-dependent units (4 divisions and 3 laboratories) namely: Environmental Forestry Division (EFD); Forest Resources Management Division (FRMD); Natural Resources Conservation Division (NRCD); Silviculture and Resources Rehabilitation Division (SRRD); the Environmental Remote Sensing and Geoinformation Laboratory (ERSG); the Soils Laboratory and the Forest Agroforest Nursery Learning Laboratory (FANLL).