 He continued his academic career in Aberdeen, becoming a lecturer in 1948, a senior lecturer in 1961, a Reader in Botany in 1964, a Professor in 1969, and a Regius Professor in 1981, a post he held until 1988.He was also a member of several governing bodies and advisory boards related to his field, including the Countryside Commission for Scotland (1980–92), the Board of Management of the Hill Farming Research Organisation (1981–87), the Council of Management of the Macaulay Institute for Soil Research (1983–87), the Governing Body of the Macaulay Land Use Research Institute (1987–90), the Advisory Board of Robert Gordon University Heritage Unit, the Scientific Advisory Committee of Scottish Natural Heritage (1996–99), the Scientific Advisory Panel of RSK Environment Ltd, and the Mar Lodge Estate Management Committee of National Trust for Scotland.He was also the convenor of the English Nature Heathlands Committee from 1981 to 1995.