The University of Oxford Botanic Garden News - Harcourt Arboretum

2 Botanic Garden News | No. 77A few words...Timothy Walker has just celebrated the 25th anniversary ofhis joining the Garden staff as General Foreman. He has beenthe Horti Praefectus since 1988; the 16th person to occupythis position since 1642. In 2002 the post was renamed‘Director’ following current Universityemployment nomenclature but the Latinsynonym remains valid.byTimothyWalkeryears of work. The World’s land area is 600times that of the UK so it would take 169million years of work by one person tobring the World up to the UK standard froma standing start. This is the equivalent of4,225,000 careers, assuming 40 years ofwork per person.Once the World has been catalogued,how many people are required to maintainthe inventory? Using UK figures again, wehave 2,000 field botanists, hence the Worldneeds 1,200,000 in total.These are, of course, approximations, butthey do show that the task of monitoringbiodiversity is a huge one. These figures arefor plants only, which are among the bestunderstood groups (together with mammalsand birds). The task facing entomology ismuch bigger.The second problem is one of method.Do we survey the World country by countryIn the past 400 yearsapproximately 7,000 botanistshave contributed to ourcurrent understanding of theBritish flora - an accumulatedtotal of 281,700 years of work.If you were asked today to compile aninventory of the World’s land plantshow would you do it? The first problemwould be one of scale: the World is avery big place, approximately 57.5 millionsquare miles or 600 times the area of theUK, and carrying out a botanical surveyof it all would probably take more than alifetime. So how many lifetimes or peoplewould you need? It is reasonable to assumethat the flora of the UK is as well recordedas that of any country. If we knew how longit has taken to carry out that recording, wemight be able to calculate how long it wouldtake to record the rest of the World’s flora.Of course some countries already havecomprehensive records, but the calculationwould still be valid.The serious study of the Britishflora could be dated from 1836 with thefoundation of the Botanical Society ofLondon, now the Botanical Society ofthe British Isles (BSBI, www.bsbi.org.uk). However it goes back to before then,perhaps to 1660 when John Ray publishedhis Flora of Cambridgeshire. There aremany 17th century specimens in the OxfordUniversity Herbarium so we could say thatthe British flora has been studied for 400years, or the equivalent of 10 professionallifetimes.Now we need to know how manypeople have been working on botanisingBritain. The Select Committee on Science& Technology cannot answer that questionaccurately (see www.publications.parliament.uk/pa/ld200708/ldselect/ldsctech/162/16206.htm) and neither can I.However, there are currently approximately100 county recorders working for the BSBIin Britain. In Oxfordshire there are at leasttwenty first-class botanists in the field, soif this county is typical, there are currentlyapproximately 2,000 skilled botanists inBritain & Ireland, or one botanist for every30,000 citizens. (You may have noticedthat I have not attempted to differentiatebetween professional and amateurbotanists; it is clear that the amateurs greatlyout number the professionals.)If you extrapolate this back to 1600 whenthere were 4 million people living in Britain,then in the past 400 years approximately7,000 botanists have contributed to ourcurrent understanding of the British flora.That is an accumulated total of 281,700or do we organize botanists by botanicalfamily? In the former case we would endup with 195 national floras; in the latterwe would have 13,000 monographs forthe genera of flowering plants alone. Themajor advantages of country floras are thatcompiling them requires less travel and theyare more useful in the field. The advantageof monographs is that they take a globalview of species delimitation. In practice weneed both. In the Herbarium in Oxford thereare floras covering a wide variety of areas,ranging the whole of the USSR to Sheffieldand its surrounding region.If you do not already have a copy of yourcounty flora, I cannot recommend it highlyenough. The current flora of OxfordshireFilming for a television series on the History of Botany tookplace at the Arboretum and the Garden over the autumn andwinter. The series, which features Timothy Walker, will beshown on BBC4 in the spring.