Prof. Dr. Ruijun Long is a Distinguished Professor in Pastoral Science and Ecology at the School of Life Science, Lanzhou University, China, and Principal Research Scientist at the State Key Laboratory of Grassland Agroecosystems. He is the founding Director of the International Centre for Tibetan Plateau Ecosystem Management and Director of the International Mountain Ecological Agricultural Hub of Gansu Province.

His expertise covers mountain ecological agriculture and food security, yak grazing behaviour, rumen ecology, energy and nitrogen metabolism, animal products and welfare, alpine rangeland management, ecosystem services, and climate change mitigation.

He previously served as Senior Ecologist and Theme Leader for Ecosystem Services at ICIMOD (2016–2019). Earlier roles include Director of Science and Technology Research at Lanzhou University, Executive Dean of Chuiying Honors College, and leadership positions at Gansu Agricultural University and Yunnan Agricultural University. He holds a PhD from Gansu Agricultural University (1995) and completed postdoctoral training at the Rowett Research Institute, Scotland (1997–1999).

Over three decades, he has authored or edited 20 books/chapters and more than 400 peer-reviewed papers, supervised over 100 graduate students, and collaborated extensively with institutions across Asia and international organisations including FAO, IAEA, UNEP, and ICIMOD.