Contortatallens roll för virkesförsörjningen på Holmen Skog, Region Iggesund
konsekvensanalys av fyra hushållningsstrategier för contortatall
Large areas of Lodgepole pine (Pinus contorta var. latifolia) were planted in the 1970s - and '80s. The purpose of the fast-growing species was to increase growth and with short rotation periods allow a rapidly increased harvest level. Today a large proportion of the young forests owned by Holmen Skog, Iggesund are covered by Lodgepole pine and an active forest management is required to spread the harvested volume over time which is desirable by a market perspective. The purpose of this essay is to investigate the possibility of spreading the harvested volume of Lodgepole pine over time. A steady harvest of Lodgepole pine can be achieved by shifting final felling in time and by thinning. The consequences of four management strategies are analyzed using PlanWise, a software program for forest-level planning and analysis in the decision support system Heureka. If the harvest of Lodgepole pine is evenly distributed over time a shortage of spruce and pine timber will occur according to previous harvest forecast. Therefore, also two fertilization programs for pine are investigated. It shows that a one-time fertilization of pine-dominated stands can increase growth by on average 13,7 m3sk per fertilized hectar, of which 4,7 m3fub is pine timber. The growth increase is distributed evenly over periods. No shortage of pine timber can be seen in the next 30 years. The harvest level depends on how Holmen choose to ration with old stands. A shortage can occur due to a lack of young age-classes today but there is a high degree of uncertainty because young forest is poorly reflected in the inventory data used.The conclusion is that an even flow of harvested Lodgepole pine can be achieved both with and without thinning, but the net present value loss with restrictions on timber flow is less with thinning because the smoothing effect of thinning. Thinning also increases the present value compared with no thinning.