SPECIES RICHNESS AND SEED DISPERSAL TO SECONDARY WOODS IN SOUTHERN POLAND

Twenty-seven secondary woods, 32-51 years old, occurring on a limestone hill near Krakow, Poland, were investigated. Twenty-five woods were Scot's pine woods; twelve of them were planted. They differ in area, shape and isolation from the primary woods. 195 species of vascular plants were found in the secondary woods, including fifty-nine small shrub and herb woodland species (out of the seventy woodland species growing in the nearby primary woodlands). Only thirteen woodland species occurred in more than a half of the secondary woods. Statistical analysis included ten independent variables (area, age, shape, distance to primary woodlands, cover of tree and shrub layer, and others) and two dummy variables. The results of a stepwise multiple regression analysis show that the number of all species depends only on area. The number of woodland species is significantly dependent on distance from the source of diaspores, area, shape, age and type of soil. The number of conifer woodland species is independent of wood age, which affects the number of broadleaf woodland species. A close relationship was found between the type of dispersal of woodland species and their distribution in secondary woods. Hovering and flying anemochores and endozoochores are the best colonizers, the worst are heavy anemochores, myrmecochores and barochores. The slow rate of the secondary succession in the study woods is due to poor colonizing ability of many woodland species as well as to the effect of the xeric conditions on the establishment and growth of seedlings.