Daddy Ruhiyat is Chairman of the Provincial Climate Change Council (DDPI) of East Kalimantan and a professor in forest soils at the Forestry Faculty of Mulawarman University.He was senior adviser to the Governor of East Kalimantan concerning the field of Natural Resource Management and Environmental Issues in 2008-2010. He joined Mulawarman University in 1973 and was appointed as dean of Faculty of Forestry at the same university 1994-2000. He was elected as Rector of High School of Agriculture in East Kutai Regency of East Kalimantan Province in 2002-2010. He did extensive research on forest soils in the humid tropics : characteristics and productivity, chemical and hydrological changes after utilization or conversion into other land uses, nutrient dynamics, nutrient cycles, soil management of plantation forest. He received his PhD in Soil Science and Forest Nutrients from Georg August University, Göttingen, Germany. He completed his Master’s degree in Silviculture from University of Tokyo for Agriculture and Technology, Japan.