Dr. A. Arunachalam is a tropical ecologist globally noted for his contributions to forest ecology, soil ecology, agroforestry, shifting agriculture and land use dynamics, particularly in the Indian Himalayan Region. He has more than 30 years of experience in teaching, research, and extension in the field of forestry, biodiversity, ecology and natural resources management. He has served as Lecturer/Asst. Professor in the North Eastern Regional Institute of Science and Technology (NERIST), Arunachal Pradesh and later in the Indian Council of Agricultural Research as Principal Scientist (Forestry), Assistant Director General (International Relations). Presently, he is Director, ICAR-Central Agroforestry Research Institute. He has guided 17 PhD students; written/edited over 21 books in English and Tamil; published over 260 research articles in national/international journals of scientific repute, over 122 book chapters and 40 popular articles.