The Global Forest Resources Assessment 2000 (FRA 2000) was the most comprehensive since FAO first reported on forest resources 50 years ago. FRA 2000 was based on the bottom-up approach, but supplemented by global level verification. The backbone of FRA 2000 was the data, information and knowledge provided by countries. Country information was verified and supplemented with "top-down" studies and remote sensing analysis using the latest technology. Countries were then invited to review and comment on the outcome of the combined global analysis. Partnerships were formed with leading institutions of particular importance is the United Nations Economic Commission for Europe served as the focal point for information about industrialized countries. This publication constitutes the principal report of FRA 2000. Part I presents the main findings on forest area and area change, the results of studies on wood volume and biomass, plantations and other key parameters studied in FRA 2000. Part II presents findings organized by geographic region and subregion. Part III describes the methodologies and processes underpinning the assessment and the mapping processes used to obtain the global maps of forest cover and ecological zones. Also described is the development of a comprehensive forestry information system (FORIS). Part IV summarizes the conclusions of the assessment, reviews the process and presents recommendations for future efforts. Finally, detailed appendixes provide terms and definitions and comprehensive tables of the global statistics presented by country and region.