Återväxt av blåbär (Vaccinium myrtillus L.) efter ångbehandling : orsaker till effektiv kontroll

Abstract: Steam was used as a site preparation method to eliminate unwanted bilberry (Vaccinium myrtillus L.) in the boreal forest. The efficiency of steam to suppress bilberry was compared with prescribed burning and cutting the bilberry. Different combinations of steaming and/or cutting the bilberry were set up to investigate in which way steaming and cutting influenced the sprouting and regrowth of bilberry. The regrowth of the bilberry vegetation was monitored for 40 month. Steam was most efficient in suppressing bilberry. Bilberry subjected to steam (compared to cut, burnt or untreated bilberry) had the significantly lowest number of new shoots and the lowest coverage. The new shoots resprouted at a deeper depth when the bilberry was subjected to steam. The reason for the slow recovery of bilberry subjected to steam is probably due to injury and death of rhizomes and buds caused by out drying effects from the standing dead bilberry vegetation. The efficiency of vegetation control and the quick technical development of steam units today may soon develope steam treatment to become a practical and economical site preparation method in forestry.