Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Forest planting as a way of species dispersal.

Abstract

Fortuitous introductions of plant species with forestry planting material used in areas deforested by air pollution were studied in the Krušné hory Mountains, Czech Republic. The number and abundance of species of higher plants accompanying spruce (mainly Picea abies, with about 20% P. pungens) saplings were recorded at three stages of the afforestation process: (1) before planting; (2) after planting; (3) after the first growing season. The reduction in the number of species and individuals during these stages of the afforestation process was monitored. In total, 39 species were brought into the site with 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), respectively. In terms of the number of species, the planting procedure itself accounted for 72% of total losses, whereas the remaining 28% died during the first year of growth on the site. In terms of the mortality of individuals, the corresponding figures were 90% and 10%. Annuals were reduced to a greater extent than perennials. Epilobium adenocaulon and Betula pendula were the most successful species in terms of the size of established population, and 8 other species previously not reported from the study area were found accompanying the transported saplings - Juncus effusus, J. bufonis, Viola arvensis, Conyza canadensis, Polygonum lapathifolium, Poa annua, Polygonum hydropiper, Lycopus europaeus, Sagina procumbens, Spergularia rubra, Carex spp., Rorippa palustris. The importance of introductions for the ruderalization of forest sites is discussed. Considering the extent (millions of saplings being planted each year) and duration (two centuries in Europe) of afforestation efforts, it is suggested that this form of dispersal has caused an important enrichment to the local flora.