The Relationships between Oak Tree Growth and Climate in Britain

SUMMARY (1) At thirteen sites in the British Isles between ten and twenty oak trees (185 in all) were sampled for dendroclimatological study. The growth ring widths were measured and, after standardization, a mean ring width index was derived for each year for each site. (2) The resulting site-index time-series were tested for climate relationships by the response function method which relates tree growth to variations in monthly temperature and precipitation. (3) Marked similarities in response functions throughout the British Isles enabled a generalized British Isles oak response function to be constructed. This shows that high rainfall, particularly in the growing season, and high temperatures in early summer favour growth. High temperatures in the previous winter, however, are detrimental to growth in the following season perhaps due to loss of food reserves.