(1871-1955) English botanist, a pioneer in the science of plant ecology. He coordinated a large project to map the vegetation of the British Isles; the results were published in Types of British Vegetation 1911. He was also instrumental in the formation of organizations devoted to the study of ecology and the protection of wildlife.
Tansley was born in London and studied at Cambridge. He founded the journal New Phytologist 1902, remaining its editor for 30 years. As cofounder of the British Ecological Society 1913, he also edited its Journal of Ecology 1916–38. From 1923 to 1924 he abandoned botany to study under Sigmund Freud, the founder of psychoanalysis, in Austria. Tansley was professor of botany at Oxford 1927–39, and chair of Nature Conservancy 1949–53.
In The British Islands and their Vegetation 1939, Tansley showed how vegetation is affected by soil, climate, the presence of wild and domesticated animals, previous land management, and contemporary human activities. He also reviewed all known accounts of British flora and then linked the two themes, thereby demonstrating which factors are important in influencing the various types of vegetation.