PATTERN AND DYNAMICS OF THE GROUND VEGETATION IN SOUTH SWEDISH CARPINUS-BETULUS FORESTS - IMPORTANCE OF SOIL CHEMISTRY AND MANAGEMENT

The vegetation and environmental conditions of south Swedish hornbeam Carpinus betulus forests are described with data from 35 permanent sam ple plots. The main floristic gradient of the ground vegetation is clo sely related to acid-base properties of the top soil: base saturation, pH and organic matter content. Other floristic differences are relate d to tree canopy cover and the distance of the sample plots to the Bal tic coast. Species richness of herbaceous plants typical of forests in creases with soil pH. The number of other herbaceous species, occurrin g in both forests and open habitats, and of woody species is not relat ed to pH. Comparisons of vegetation data from 1983 and 1993 show relat ively small compositional differences of the herbaceous forest flora. The number of other herbaceous species increased considerably in those plots where canopy trees had been cut after 1983. The number of new s pecies in managed plots increases with soil pH. Species losses and gai ns of the herbaceous forest flora between 1983 and 1993 are generally lower as compared with other herbaceous species and woody species. How ever, the ground cover of herbaceous forest species, especially of Oxa lis acetosella and Lamium galeobdolon, was considerably lower in 1993 as compared to 1983 in both unmanaged and managed plots. Possible expl anations for this decrease are current soil acidification and drought during the growing season.