Natural variability of forests as a reference for restoring and managing biological diversity in boreal Fennoscandia

Abstract

In Fennoscandia, use of the natural forest as a reference for restoration and management of forest biodiversity has been widely accepted. However, limited understanding of the structure and dynamics of the natural forest has hampered the applications of the natural variability approach. This is especially the case in areas, where the natural forests have almost totally vanished. This review was motivated by the idea that despite these diffi culties the essential features of the natural forest can be reconstructed based on biological archives, historical documents, research done in adjacent natural areas, and modeling. First, a conceptual framework for analyzing the relationship between forest structure, dynamics and biodiversity is presented. Second, the current understanding of the structure and dynamics of natural forests at different spatiotemporal scales in boreal Fennoscandia is reviewed. Third, the implications of this knowledge, and gaps in knowledge, on research and on practical restoration and management methods aimed at forest biodiversity conservation are discussed. In conclusion, naturally dynamic forest landscapes are complex, multiscaled hierarchical systems. Current forest management methods create disturbance and successional dynamics that are strongly scale-limited when compared with the natural forest. To restore some of the essential characteristics of the natural forest's multiscale heterogeneity, diversifi cation of silvicultural and harvesting treatments, as guided by natural disturbance dynamics, is needed to produce more variation in disturbance severity, quality, extent, and repeatability.

Natural stand structures, disturbance regimes and successional dynamics in the Eurasian boreal forests: a review with special reference to Russian studies

“…Currently, the attempts to develop sustainable forest management call for better understanding of natural forest structure and dynamics. Knowledge is needed on central ecological characteristics and processes in the natural forest, such as structure, composition, disturbances, regeneration and successional dynamics (Attiwill, 1994;Kuuluvainen, 2002). For example, the question as to what extent forests are naturally even-aged or uneven-aged has been debated since the 19th century.…”

“…For example, arguments for the natural predominance of stand-replacing disturbances and even-aged stands have been used to legitimatize clear-felling as a natural management system (Sirén, 1955;Valyaev, 1984). On the other hand, where less severe disturbances are the norm and pristine stands are mostly uneven-aged, selective cutting should be promoted if the aim is to maintain the structure and ecological characteristics typical of the forest site type (Dyrenkov and Shergol'd, 1973;Kuuluvainen, 2002;Volkov, 2003).…”

“…A large part of the reviewed studies are written in Russian, and most of them have not been included in earlier reviews (Angelstam, 1998;Angelstam and Kuuluvainen, 2004;Gromtsev, 2002;Kuuluvainen, 1994Kuuluvainen, , 2002. The review is also used to synthesize and classify different types of structure and dynamics characteristic of pristine boreal forest stands.…”

Restoration of Southern Pine Forests After the Southern Pine Beetle

“…Understanding the structure and function of natural forested ecosystems forms the necessary basis for all forest restoration activities (Landres et al 1999, Kuuluvainen 2002. Knowledge of the composition, structure and function of natural forests (i.e., the average values) is needed to set goals for restoration and to evaluate the success of particular restoration actions.…”

The effect of contrasting management types on two distinct taxonomic groups in a large-scaled windthrow

“…Treatments applied by forest managers aimed at reducing the probability of the occurrence of natural disturbances (e.g., monitoring of folivorous insect populations, chemical protection against insects or fungi, removal of decaying trees and dead wood, regulations concerning fire prevention, and many others) have played an important role in forestry (Niemelä 1999). As a consequence, the role of disturbances and importance of disturbing agents (e.g., natural fires) in managed stands has been largely suppressed in comparison with those which are not managed (Kuuluvainen 2002).…”