The records in this collection date from Alan Mitchell's teenage years when he meticulously kept lists, diaries and drawings of his observations of birds. His diaries have the added interest of references to local incidents during World War II (see -/2/1-5). Mitchell's detailed notes and data from his bird watching were compiled into graphs, censuses of bird varieties, maps and lists. This attention to detail is later seen in the statistics and data Mitchell accumulated and interpreted on the growth and measurement of trees.
Mitchell continued to make daily lists of birds seen when he was working at Alice Holt Forest for the Forestry Commission in 1946-1947, before leaving to study at Trinity College, Dublin (see -/2/6). When he qualified and returned to Alice Holt Forest, Mitchell made a daily list of birds seen on his bicycle on his journey from Tilford to the Forestry Commission (see -/2/8-9). Eventually Mitchell amalgamated all his ornithological statistics from 1939 and kept them updated until 1990 (see -/2/10).
Alan Mitchell's dendrology papers in this collection cover many of his interests including the development of the Leyland cypress (see -/3/1); the effects of acid rain on trees and the environment (see -/3/7); and his statistics recording the phenology of broad leaved trees and conifers (see -/3/2). On Mitchell's many visits to North America between 1971 and 1992, he made extensive notes on birds and trees he observed and these are also included in these papers (see -/3/12-22).
A selection of Alan Mitchell's academic papers, guide books, lecture notes and published works in journals and newspapers between 1953 and 1994 also survives reflecting his wide spectrum of knowledge and interest in his different fields of study.