Ariel E. Lugo was born in Mayagüez, Puerto Rico. He received his BS and MS from the University of Puerto Rico, and in 1969 obtained his Ph.D. in Ecology from the University of North Carolina at Chapel Hill.

Lugo has been Assistant and Associate Professor of Botany, University of Florida at Gainesville (1969-1979); Assistant Secretary for Planning and Resources Analysis (1973-1974), and Assistant Secretary for Science and Technology (1974-1975) with the Puerto Rico Department of Natural Resources; Staff Member in the Council on Environmental Quality, Executive Office of the President from 1978 to 1979; Project Leader at the US Forest Service (1979-1992), Director (1986-1992), and Supervisory Research Ecologist at the then Institute of Tropical Forestry. When the Institute became the International Institute of Tropical Forestry in 1992, Lugo was Acting Director from 1992-1994. In 1994 he was appointed to the Senior Executive Service and from February to March of 1995 was in Washington, D.C. as Acting Deputy Chief of International Forestry.

He is currently the Director of the Institute. His current research includes: assessment of the role of tropical forests in global processes; ecological studies of tropical tree plantations; comparisons of tree plantations and natural forests; relation between forest management and soil and water quality in Caribbean forests; response of tropical forests to disturbances; studies of tropical wetlands; studies of wood decomposition rates in the tropics; and the ecological role of introduced species in the tropics. He has published over 510 scientific articles, is a highly cited researcher, has been an expert witness in federal court on several environmental cases, has been consulted on various environmental issues at the local, national, and international level, taught various classes and short courses at several universities, been advisor to over ten graduate students. Lugo is also an editor for various scientific journals.