EFFECT OF SHRUB LAYER ON THE INTERCEPTION PROCESS IN DECLINED CLIMAX SPRUCE FORESTS IN THE TATRA NATIONAL PARK (SLOVAKIA)

The impact of shrub layer on the interception process in declined climax spruce forests in the Tatra National Park was studied on the research plot Cervenec situated at an elevation of 1,420 a.s.l, in the Western Tatras Mts. The field research was carried out on an open forest area, without forest stand. This open forest area has been created after the decline of the former climax spruce forest. Open forest area consist of bilberry (Vaccinium myrtillus L.) and red raspberry (Rubus idaeus L.). The data were collected during the growing seasons 2011 to 2018. The growing season at Cervenec lasts approximately from May to October, dependent on the weather conditions. The precipitation measurements were performed repeatedly, at about two-week intervals. The final interception values were calculated from the difference between the precipitation recorded in the open area and the precipitation totals measured in the stand of shrub layer. The results suggest that the average interception loss during the years 2011-2018 under the stand of red raspberry (Rubus idaeus) was lower by 34 % compared with the bilberry (Vaccinium myrtillus L.).