A comparison of biodiversity values in boreal forest regeneration areas before and after forest certification

In this study, 236 regeneration areas (mostly clear-cuts) in southern Norway were selected by random stratified selection: 118 of the study units were cut before and 118 after the introduction of forest certification in 1998. The degree of compliance with biodiversity measures established in the prevailing certification standard (ISO 14001 and the Norwegian standard "Living Forests'') was compared in a field study, and the differences were analysed. In some aspects, a clear difference could be seen, most clearly in an increasing number of green retention trees and an increasing mean width of buffer-strips left along rivers, bogs and lakes in the postcertification units compared with the precertification units. Even though there was a significant increase in the mean number of retention trees, as much as 21% of the postcertification regeneration areas still did not have sufficient retention trees to comply with the certification standard and 41% had either too few retention trees or too few spruce trees according to the standard. Concerning the management of small swamp forests, and the damage done to terrain and prelogging coarse dead wood by off-road transport, little improvement was seen. The discussion examines whether it is probable that the changes seen are a result of forest certification in Norway.