QUANTITATIVE ESTIMATES OF COARSE WOODY DEBRIS AND STANDING DEAD TREESIN SELECTED SWISS FORESTS

Coarse woody debris and standing dead trees play a crucial role in bio diversity and the functioning of forest ecosystems. Little information is currently available concerning the amount and distribution of coar se woody debris in Swiss forests, and little is known about the relati ve abundance of lying dead trees and standing dead trees in managed an d unmanaged forests. In this study, data were collected from eleven si tes in order to assess the volume and the decay stages of coarse woody debris and of standing dead trees. There were substantial differences in deadwood volume between sites, but sampling variability was high. The amount of dead wood found in the study sites was substantially sma ller than the estimated amount from studies in virgin forests and in t he range of values found for other managed and unmanaged forests in Eu rope. Most of the dead wood material belonged to young decay states. A s expected, there was more dead wood in unmanaged than in managed stan ds, and in mature stands as compared with young stands. In particular, most unmanaged stands had significantly more standing dead trees than most managed stands, indicating that, in Switzerland, diseased and de ad trees are removed by salvage cutting.