Modelling the amount of coarse woody debris produced by the new biodiversity-oriented silvicultural practices in Sweden

One of the most important measures adopted in the new biodiversity-oriented forestry in Sweden is to increase the quantity of coarse woody debris (CWD) in commercially managed forests, by leaving existing dead trees as well as ensuring input of new dead trees. We have used a simulation model in order to predict the quantity of CWD of Norway spruce (Picea abies (L.) Karst.) in forest landscapes subject to different management regimes. It is shown that in an average, managed forest landscape in Sweden, where the management regimes are changed in order to follow the current requirements for certification by FSC, the amount of CWD will be more than doubled, but it will take more than 100 years to reach the-new level. The increase in the amount of CWD will first be recognised for hard (less decayed) CWD and mainly in young, newly cut stands. Leaving forests unmanaged, retaining living trees and decreasing the destruction of CWD at final cutting, and not removing naturally dying trees are all measures that have a strong positive influence on the amount of CWD. (C) 2003 Elsevier Ltd. All rights reserved.