A mutual climatic range method for reconstructing palaeoclimate from plantremains

The mutual climatic range (MCR) technique for reconstructing palaeoclimate relies on establishing the present-day climatic tolerance ranges of living species which are also found as fossils in Quaternary deposits. The palaeoc limate under which the species in a fossil assemblage co-existed can be inf erred to lie within the intersection of the individual species' tolerance r anges. This paper describes a factor analysis of modern European climate da ta to determine two compound variables that describe the main features of t he climate: 'summer warmth and dryness' and 'wetness and winter warmth'. Di stribution maps of 80 plants from Atlas Florae Europaeae were combined with the climate data to determine each species' climatic range in factor space . MCRs were determined for two living plant assemblages from southeast Engl and and found to give a reliable, although rather imprecise, reconstruction of the true thermal and precipitation climate. Reconstructions for two pla nt macro-fossil assemblages from Devensian gravels at Earith, Cambridgeshir e, demonstrated palaeoclimates that were colder and more continental than t he present, bur with similar total amounts of precipitation. The study demo nstrates the potential of the MCR method for use with Quaternary macrofossi l plant remains, although there are methodological drawbacks in employing a climate-space defined by factor analysis.