Impact of clear cuttings on biodiversity of boreal forests

Abstract

The dynamic of chemical composition of forest soil, understory plants and variation of insects were investigated in Pinus sylvestris dominated forests after clear-cuts. We detected an increase in litter pH, while soil investigations have shown that concentrations of Ca2+ and Mg2+ also increased in the clear-cut areas. Significantly higher amounts of NO3 -N+NO2 -N mg kg-1 and NH4-N mg kg-1 were determined after clear-cutting, while the mobile P2 O5 and K2 O decreased in forest litter and mineral soil (in 0-10 cm depth) in clear-cut plots. We predict that suddenly increased supplies of NO3 -N+NO2 -N and NH4 -N influenced the development of Ericaceae species negatively. Logging residues could be extracted in Arenosols in order to avoid enhanced leaching of organic carbon and nutrients, especially mineral nitrogen. Clear-cuttings demonstrated a negative effect on the abundance of forest-related dwelling beetles, both in terms of species number and individuals in litter assemblages. However, clear-cuttings did not significantly reduce the total species richness because the quantity of beetle assemblages was supported by numerous open land or eurytopic species. Increased amount of new flowering plant species in clear cut areas effected mutualistic relationships of pollinators positivelly. Reaction and possibilities to restore different populations of Ericaceae are species-specific. Vaccinium vitis-idaea is able to survive after clear-cut damages The ability of this drought resistant species to spread through underground rhizomes would promote its reproducibility. Nevertheless, the rhizomatous plant Vaccinium myrtillus demonstrated significantly stronger negative response in the cutted forests.