%0 Research Notes %T Peatland forestry research in Sweden %A Hökkä, Hannu %A Penttilä, Timo %D 1991 %J Suo - Mires and peat %V 42 %N 1 %U http://suo.fi/article/9679 %X Former and present peatland forestry studies by the Department of Forest Soils of the Swedish University of Agricultural Sciences (Umeå) are presented, based on a tour to field experiments in north, mid and south Sweden. Up to the 1970s, major interest was paid to the nutrition of drained, originally treeless or sparsely treed fens and bogs. Several fertilization experiments since the first wood ash trials in Norra Hällmyren have indicated the necessity of P and K application to ensure afforestation and satisfactory growth of Scots pine on such sites. Silvicultural problems on drained peatlands, such as regeneration on highly productive peatlands, planting techniques, commercial thinnings, as well as gas exchange in peat and the distribution of nutrients in a peatland forest ecosystem are the focus of a large-scale project started in 1985. The preliminary results of the regeneration experiments, i.e. the effectiviness of spruce shelter wood (140-200 trees per ha) against frost damage during the growing season, are discussed. A brief description of the present classification and post-drainage site index system for peatlands is also given. Keywords: Classification, drainage, nutrient status, regeneration