Response of life forms of understory plants to clear-cut logging

Anthropogenic disturbances of the boreal forest ecosystems are defined as important ecological processes with significant long-term influence on biogeochemical cycles and vegetation. The development of understory plants immediately after clear-cut logging was studied in Lithuanian boreal Scots pine forests. Experiments were carried out in Vacciniosa forest types. The mature forest stands and the clear-cutted areas were compared. We have determined the different response of Ericaceae shrubs Vaccinium vitis-idaea, Vaccinium myrtillus and Calluna vulgaris to changed environmental conditions after clear-cuttings. Lycopodium annotinum and Goodyera repens were defined as the most sensitive because small populations of these species disappeared in the cutted areas. Juvenile populations of L. annotinum most likely were destroyed after soil preparation for new forest planting. Mosses were damaged exceptionally strong, some species disappeared in the clear-cutted areas as well. Considerable decline of dwarf shrub layer confirmed the negative reaction of this dominated understory life form however, the dynamic of different vascular plants demonstrated species-specific response to changing environmental conditions. Because of rapid changes of light as well as damage of rhizomes by soil disturbances, the values of mean cover of the studied Ericaceae species decreased. Spread of C. vulgaris renewed through seedlings and the number of new annual and perennial light-demanding and nitrophilic herbs species was significant in both forest types in two years after cuttings. This study corroborated the importance of evaluation of understory plants before cuttings and will promote the implementation of protection of sensitive species and non-wood forest resourcesVytauto Didžiojo universiteta