Thirty-four years ago today, on April 16, 1991 (March 2, 1991 lunar calendar), ecologist Hou Xueyu passed away. Professor Hou Xueyu was born in Hexian, Anhui Province on April 2, 1912. He graduated from the Department of Agrochemistry, College of Agriculture, Nanjing Central University in 1937, and from 1945 to 1950, he received a master's degree and a doctorate at the Research Institute of Pennsylvania State University in the United States. Shortly after the founding of New China, he resolutely returned to China with the heart of serving the country with fists and resolutely returned to China and established the first plant ecology laboratory in our country. He was one of the main pioneers and founders of plant ecology and geobotany in New China. He also served as a professor at Tsinghua University, Peking University and other institutions of higher learning. He has represented the country or our country's scientific community to attend international conferences and field trips abroad many times, and his footprints are all over the world. His academic works have been widely praised by the international ecological and geobotanical community, and have made outstanding contributions to the exchange of ecological science in our country and foreign ecological science. Professor Hou Xueyu has profound knowledge, profound attainments, keen and active academic thoughts, and outstanding scientific research achievements. He believes that soil properties are obviously affected by the properties of parent rocks, breaking the traditional view that climate alone determines soil properties. He was the first to study and discover soil indicator plants in China, and discovered a number of plants enriched with certain elements. He also made outstanding contributions to the study of latitude zoning, longitude zoning and mountain vertical zoning of vegetation geographical distribution, establishing a theoretical basis for China's vegetation zoning. He himself became a pioneer in compiling China's vegetation map and set a world precedent for compiling agricultural vegetation maps. Hou Xueyu paid attention to the production of agriculture, forestry, animal husbandry and sideline fisheries, and put forward the view of "big agriculture, big grain", which has important strategic significance for the development of agriculture and the improvement of the environment in our country. In his decades of scientific research and teaching work, Hou Xueyu taught tirelessly and trained a large number of scientific research and teaching talents in plant ecology and geobotany for our country, many of whom were leaders of the discipline and well-known scientists and professors. He did his best to develop our country's scientific cause. He died on April 16, 1991.