Recent trends in beech tree health in southern Britain and the influence of soil type

The health of beech (Fagus sylvatica L.) at sixteen sites of high nature conservation value in the U.K. has been assessed annually since 1987. Survey results show that, from 1987-1992, beech health (as measured by crown thinness) deteriorated markedly at many sites, but a substantial recovery was seen in 1993 and 1994. However, results from a crown architecture assessment indicate that beech health has continued to decline steadily throughout the study period. Tree health is related to soil type, with health being worse on poorly drained, acidic soils. An involvement of climate and perhaps also ozone is suggested given the deterioration in health after the dry summers and high ozone concentrations of 1989 and 1990. These results support earlier findings that climate, in particular the severe drought of 1975/76, had long term effects on canopy development of trees at some of the sites.