Fergus Sinclair leads the Centre’s research into the contribution that trees can make to the productivity of farming systems and the lives of rural communities. This theme has two main areas of focus: soil and water productivity; and factors affecting farmer decisions about which trees they incorporate on their farms and how they manage them. He also co-ordinates the Smallholder Production Systems and Markets component of the CGIAR Research Programme on Forests, Trees and Agroforestry involving CIFOR, Bioversity and CIAT. Sinclair also works with Bangor University, Wales, UK through a research partnership with the School of the Environment, Natural Resources and Geography, and is a visiting professor at the Latin American Centre for Tropical Agricultural Research and Higher Education (CATIE) in Costa Rica. He is best known for his pioneering research on systematic acquisition and use of local knowledge and the development and application of systems methods in agricultural development, including measurement and modelling of complex systems at field, farm, livelihood and landscape scales, encompassing both ecological and human dimensions.