Skötselåtgärder vid nyetablering av skyddszoner vid bäckar i södra Värmland

Abstract: Buffer zones play an important role for the water quality in our watercourses. When harvesting a forest close to a watercourse a buffer zone should be left. When it's not left, it will lead to radical changes in the environment for the water organisms. The overall purpose of this thesis was to illuminate the production- and environmental thinking when establishing new buffer zones in south of Värmland. The partials goals were to determine choice of tree species, ways of regenerate, occurrence of soil scarification and the occurrence of machine tracks in newly established buffer zones. To full fill these purposes a field inventory was made of harvested buffer zones. The clear cuts were chosen from the database from the project "Skog och Vatten" run by the forest authorities in Värmland/Örebro. More than one hundred watercourses have been inventoried in field. A little bit less than 2/3 of them were cut on both sides of the watercourses while the rest were cut only on one side of the water course. The mixture among tree species was broadleaved trees>spruce>pine. The broadleaved trees mixture was birch>alder=aspen=other broad leaved trees. It turned out that plantation was as common as self regeneration in harvested buffer zones. Where it was planted the soil was also scarified. If the water course was harvested on both sides of the watercourse the probability of plantation, soil scarification and machine tracks increased, compared to where they had harvested on only one side of the watercourse. It was more common that they had planted in the 5-10 m zone then in the 0-5 m zone. At thin water courses the occurrence of soil scarification and machine tracks were more common then at wider watercourses. Shallow machine tracks were more common than deep ones. The results have been evaluated according to the forest law, certification norms, and environmental policies of different forest organizations. Recommendations for management of future buffer zones will be given.