John William Bews ('Bewsy' to his friends) was the son of James Bews, a farmer, and his wife Mary, born Dearness. He received his schooling in and around Kirkwall and continued his studies at the University of Edinburgh, which awarded him the degree Master of Arts (MA, 1906), then a first degree at Scottish universities, in mathematics, natural philosophy, chemistry, geology, Latin, English and logic. This was followed by a Bachelor of Science degree (BSc, 1907) with special distinction in botany, chemistry and geology. During his school and university education he showed exceptional ability and consequently received many prizes, bursaries and scholarships. He started his professional career as a lecturer in economic botany at the University of Manchester, but in 1908 returned to the University of Edinburgh as lecturer in plant physiology and assistant professor of botany. That same year he published his first two botanical papers. In 1909 he was appointed professor of botany and geology at the newly established Natal University College in Pietermaritzburg, though he arrived in South Africa only in August 1910.
Bews had intended to specialise in plant physiology. However, the lack of adequate laboratory facilities in Pietermaritzburg and the challenge of what was to him a new vegetation turned his interest to field work. He immediately started a study of the local vegetation, particularly from an ecological viewpoint. He soon made contact with J.M. Wood* and J.S. Henkel*, and often botanised with T.R.Sim*, travelling on foot or on his bicycle. Soon he produced his first paper on the local flora, "The vegetation of Natal" (Annals of the Natal Museum, 1912). During his first two years in Natal he visited Britain three times. While there in December 1912 he married Williamina E.C. Mackay. That same month he was awarded the degree Doctor of Science (DSc) by the University of Edinburgh for his investigation of the ecology of the Natal Midlands. His findings were published in "An oecological survey of the midlands of Natal, with special reference to the Pietermaritzburg district" (Annals of the Natal Museum, 1913). Subsequent papers in the same journal dealt with the vegetation of the Drakensberg (1917) and the Natal coastal belt (1920). Other papers dealt with "The growth forms of Natal plants" (Transactions of the Royal Society of South Africa, 1915/6), plant distribution in South Africa and the origin and migration of the South African vegetation (Annals of Botany, 1920-1922), "South African phytogeography" (South African Geographical Journal, 1917), and related topics.
Bews' botanical research was reported on also in several books. Grasses and grasslands of South Africa (Pietermaritzburg, 1918) included a key to the genera and species, put forward the theory that the nutritive value of a grass is inversely proportional to its fibre content, and attempted to show the effects of soil erosion, grass burning, overstocking, and weed control on various kinds of grassland. An introduction to the flora of Natal and Zululand (Pietermaritzburg, 1921) contained keys to the families and genera and a full list of species, with distributional notes on each. Plant forms and their evolution in South Africa (London, 1925) further developed the work reported earlier in the Annals of Botany. This book established the author as one of the leading plant ecologists in the world. Studies in the ecological evolution of the angiosperms (1927) was a reprint of papers published in the New Phytologist in 1926. On a more ambitious scale and perhaps his most important work was The world's grasses: their differentiation, distribution, economics and ecology (London, 1929). In 1918 he was appointed botanist in charge of the eastern area of South Africa under the Botanical Survey and, with R.D. Aitken, wrote two Memoirs of the Botanical Survey of South Africa in which they reported their "Researches on the vegetation of Natal" (1923, 1925).
Bews' research followed well defined lines such as ecological analysis, plant succession studies, study of plant growth forms, floristic work, plant physiology, and phylogeny. As a botanist of international repute he did much to establish advanced botanical studies in South Africa. He not only trained many of South Africa's leading botanists, but several of his students obtained important botanical posts in other British colonies. However, he was also an outstanding educational administrator who played an important role in the advancement and administration of Natal University College and became its principal in September 1930. He also served as a member of the council of the University of the Cape of Good Hope (1916-1918) and its successor, the University of South Africa (from 1918 to his death); was an examiner in botany for the University of the Cape of Good Hope (1913-1916); was chairman of the senate of the University of South Africa (1922-1924 and 1934-1936), and dean of its Faculty of Science (from 1921); was a member of the Joint Matriculation Board; and a member of the Research Grant Board (from 1918). During 1925-1927 he was granted leave to spend 18 months as professor of botany in the University of Durham, at Armstrong College, Newcastle-upon-Tyne. As a result of all his commitments his botanical research came to an end in 1930. None the less his many involvements in educational and research institutions, wide knowledge and friendly manner made him one of the best known South African scientists. In his spare time he developed an interest in human ecology, that is, the application of his study of plant life to human society. He wrote two books on the subject, Human ecology (1935) and Life as a whole (1937).
Bews was elected a Fellow of the Royal Society of South Africa in 1920 (and served on its council during 1923-1924) and a Fellow of the Linnean Society in 1926. For many years he was a member of council of the South African Association for the Advancement of Science, served as president of Section C in 1921, as president of the association in 1931, and received its South Africa Medal and Grant the next year. In 1923 he and Professor S. Schonland* represented the South African government at the Imperial Botanical Conference. Bews became a foundation member of the South African Biological Society in 1917 and served on its council for at least the first two years.