De Jong has a forest science background. He worked as associated researcher at UNAP, INIA and IIAP, Peru, and as international fellow at the NYBG’s Institute of Economic Botany. Since 1995 he joined CIFOR. In 2004 he became professor at the National Museum of Ethnology, Osaka, and in 2006 at Kyoto University, Japan. He studies forest governance, smallholder and community forestry, forests and climate change, and forest restoration and transition in Bolivia, Peru, Indonesia, Vietnam, India, and China. Currently he is adjunct professor at Renmin University of China, guest researcher at China Agricultural University and emeritus professor at Kyoto University.