FOREST PLANTING AS A WAY OF SPECIES DISPERSAL

Fortuitous introductions of plant species with forestry planting mater ial used in areas deforested by air pollution were studied in the Krus ne hory Mountains, Czech Republic. The number and abundance of species of higher plants accompanying spruce saplings were recorded at three stages of the afforestation process: (1) before planting; (2) after pl anting; (3) after the first growing season. The reduction in the numbe r of species and individuals during these stages of afforestation proc ess was monitored. In total, 39 species were brought into the site wit h pre-grown saplings and 14 (36%) became successfully established; the corresponding figures for the total number of individuals were 524 (i .e. 1.024 per sapling) and 56 (i.e. 10.7% of the original number), res pectively. In terms of the number of species, the planting procedure i tself accounted for 72% of total losses, whereas the remaining 28% die d during the first year of growth on the site. In terms of the mortali ty of individuals, the corresponding figures were 90% and 10%. Annuals were reduced to a greater extent than perennials. Epilobium adenocaul on and Betula pendula were the most successful species in terms of the size of established population. Eight species previously not reported from the area under study were found accompanying the transported sap lings. The importance of introductions for the ruderalisation of fores t sites is discussed. Considering the extent (millions of saplings bei ng planted each year) and duration (two centuries in Europe) of affore station efforts, it is suggested that this form of dispersal has cause d an important enrichment to the local flora.