Are large clearcuts the only way to manage forests? : a study of economic performance and deadwood production of various silviculture systems

Sammanfattning: Our forests are a natural resource which is needed for many purposes. Their importance and different values are expressed in the Swedish legislation, where production and environmental goals are set as equal. To many it is not sufficient, there has been a debate regarding how forests are managed and the practice of clear-cutting for decades. Rotation forest management (RFM) is often set against continuous cover forestry (CCF). Economy is not the only driver when it comes to forest management, but alternative regimes will not be used on a larger scale if they are not compatible with silviculture used today. This study aims to investigate if it is possible to apply a different management with the same or better financial result, and at the same time benefit biodiversity. Biodiversity was measured by the amount of deadwood and financial value with net present value (NPV). Data from eight clearcuts exceeding 20 ha in size, six in northern and two in southern Sweden, were used to simulate one rotation in Heureka PlanWise DSS. The scenarios were rotation forest management (RFM), continuous cover forestry (CCF), leaving a part unmanaged in combination with RFM, fertilizing every ten years, a combination of CCF and RFM, fertilizing and CCF and dividing the site in three parts clearcutting the site with 10-year intervals. The conclusion was that both CCF and intensive forestry had a higher NPV than RFM. The result varied with site index, tree composition and location in the country, with higher NPV for sites in northern Sweden with lower site index. The measured volume of deadwood was highest when leaving a third of the site unmanaged and two thirds with RFM for all sites except one in northern Sweden and came at a high cost with a much lower NPV for all sites. The result shows that it is possible to manage our forests without taking up large clearcuts with the same, or even better, financial result. Depending on the property owners` goals one or several management regimes could be used resulting in a more varied landscape and at the same time benefit biodiversity and resilience in a changing climate.