Abstract

Scientific studies on forest stand climatology of boreal forests in the Oulanka Nationalpark region, Northern Finland, with it regard its function as a control and a filter in landscape ecosystems and with special reference to strata specific interception and leaching by drop and seeping water were carried out during spring, summer and autumn 2006. As a part of these scientific works differences between an Empetrum-Myrtillus-old growth forest (OGF) and a Pinus sylvestris-reforested area (RA) concerning to interception in tree-, shrub-, dwarf-, moss- and litter layer and soil depths of 10, 30 and 50 cm (seeping water) were studied.

The first results show a clear depence of interception to different rainfall features and rainfall intensities. Concerning the predominantly long rainfall events, those particularly took place during springtime, is shown, that the bulk of throughfall (> 90%) both in OGF and in RA is dropping down to the dwarf layer. In contrast to that, the amount of rainfall in moss- and litter layer achieved nearly 20%. During drizzle-rainfall events these layers remained to be dry. Depending of whether such an event took place after a long rainfall event or after a long dryness period, differences concerning to wetting capacity were carried out in the tree layer. Thus, in RA 20% of drizzle rainfall events after long dryness periods have reached layers below the tree layer, in contrast to the OGF, in which nearly 60% have achieved the dwarf layer.