Stand Structure in Semi-Natural and Managed Forests in Eastern Finland and Russian Karelia

• Published in: Ecological bulletins 2001-01 (49), p.149-158
• Main Authors: Uotila, Anneli, Maltamo, Matti, Uuttera, Janne, Isomäki, Antti
• Format: Article
• Language: English
• Subjects: Boreal forests; Coarse woody debris; Coniferous forests; Forest ecology; Forest stands; Old growth forests; Seminatural ecosystems; Stand management; Sustainable forest management; Trees
• ISSN: 0346-6868

The aim of this study was to examine the stand structure of semi-natural and managed, mesic and sub-xeric Scots pine and Norway spruce forests in eastern Finland and Russian Karelia. The data covered a total of 79 stands measured during the years 1994-1998 in eastern Finland and in the Russian Federation. The plots used in the study represent both currently unmanaged and managed forests. The unmanaged forests, which we call semi-natural (due to slash-and-burn agriculture and light selection fellings), are located in nature protection areas. The studied variables were volume of the living tree stock, volume of the coarse woody debris (CWD), the number of tree storeys, number of tree species, proportion of deciduous trees, number of living stems, stumps, diameter range at breast height (dbh) and stand basal area. The differences between the managed and semi-natural stands were tested statistically over the entire data using analysis of variance (covariance based). Of the chosen stand characteristics, both the standing CWD and CWD on the ground, the number of tree species and the dbh range differed statistically between the managed and semi-natural forests. The average volume of CWD in both soil fertility classes was greater in the semi-natural forests over all succession stages, and it was clearly at its greatest after forest fires and lowest in the young stage. The proportion of deciduous trees differed only between the soil fertility classes. The number of tree species in managed forests was greater than that in semi-natural forests in all successional stages apart from the clear cut/burned phases. The dbh range showed considerably larger variation in semi-natural sapling and young forests. The number of living stems was greater in the managed sapling stage, while the volume of the tree stock was higher in the semi-natural sapling forests. Processes resulting in several tree storeys and the maintenance of coarse wood debris should be utilised in achieving more ecologically sustainable forest management. This means, on the one hand, lengthening the rotation while, at the same time, keeping stands in the intermediate successional stages more densely stocked.