Colin Graham Trapnell was born in 1907. He was educated at Sedbergh School and later read Classics at Trinity College, Oxford. However, his real interest lay in Science as he had been a keen botanist since his school days. While at Oxford, he joined Max Nicholson in founding the Oxford University Exploration Club in 1927 and in organising its first expedition to Greenland in 1928. His Greenland work was published in 1928. Trapnell then applied for a post as Ecologist at the Colonial Office and in 1931 obtained his first posting as Government Ecologist to Rhodesia. His task was to reconnoitre and map soils, vegetation types as well as indigenous agriculture of the whole territory, a task that would take him ten years. The task was generally carried out on foot, as there were in those days few tracks suitable for motor vehicles. Trapnell and his colleagues would depart for six months at a time, using native bearers carrying essentials such as medical supplies and food. For many of the native tribes they encountered, this was to be their first sighting of white men. The surveys, the first of their kind to cover a whole African country, were published after the Second World War and have recently been republished (2004) as they are still the basic source of essential natural resource data for the country 'The Soils, Vegetation and Traditional Agriculture of Zambia' is in two volumes with accompanying maps.
In 1948, Trapnell organised experiments across Zambia on behalf of the Colonial Office to assess land for possible groundnut production; significantly the Overseas Food Corporation decided not to start a ground nut scheme in Northern Rhodesia. The schemes which failed in Tanganyika lacked the kind of survey undertaken by Trapnell in Rhodesia. His work in Rhodesia was considered by the Colonial Office as a foundation for a wide range of projects, especially on African agriculture. In the 1950s he was asked to train ecologists for work in Africa, ranging from large scale vegetation and soil surveys to investigations into Tsetse and desert locusts infestation.
In 1960, with J E Griffiths, he completed a study on the rainfall altitude ratio in relation to the natural vegetation zones of southwest Kenya. Meanwhile, the Kenya Department of Agriculture asked him to prepare an overall vegetation map covering 40,000 square miles of southwest Kenya. This major undertaking was not completed for several years after his retirement.
Upon his retirement, Trapnell joined a small group of people engaged in founding the Somerset Trust for Nature Conservation, now the Somerset Wildlife Trust. He organised land use surveys for conservation purposes of the Mendip Hills and the Somerset Peat Moors, and was responsible for the Trust's acquisition of its first nature reserves at Catcott and West Ham. For thirteen years he was Chairman of the Leigh Woods committee management for the National Trust and was also responsible for negotiating the lease of the woods to the Nature Conservancy Council to form the Avon Gorge National Nature Reserve. At the same time, from his home in Bristol, he was engaged in the completion of the interpretation of air photographs for the vegetation and climate maps of southwest Kenya, the sheets of which were published successively by the Directorate of Overseas Surveys between 1966 and 1986.
In 1994, he started the Trapnell Fund for Environmental Field Research in Africa at Oxford University, to support research into African environment. The fund established a fellowship at the Environment Change Institute, and the first Trapnell Fellow was appointed in September 1991. In the last three years of his life, although aged over 90, he collaborated with Paul Smith at the Royal Botanic Gardens, Kew, to produce a three volume ecological survey of Zambia. He was appointed OBE in 1957. He died on 9 February 2004, aged 96.