Forest is the main biotic component in Karelia. Forests cover some 70% of the territory (largest lakes within forest areas not included). The forest cover plays a key role in environment formation and protection. It is responsible for the status and quality of terrestrial faunal and floral complexes, surface and ground waters, soil cover and microclimate.

Fig.1 Forest habitat map (orange - pine, violet - spruce)

Forests cover c. 70% of the Suojärvi District territory. In most of the territory swamp forests and open mires occupy equal proportions of land. Among forest habitats, the cowberry (40%) and bilberry (35%) groups of forest types dominate, and a slightly smaller proportion of the forest area (20%) is under dwarf shrub, sedge-sphagnum and other wet habitats. The forest cover is clearly dominated by pine habitats (>75%), i.e. those where pine forest had grown prior to logging (fig. 1). Nearly a half of the district forests today is young stands below 40 years, whereas forests older that 100 years occupy about 20% of the territory.

Most common and widespread are bilberry, cowberry and dwarf shrub-sphagnum pine forests, as well as bilberry spruce forests (fig. 2, 3). Tree stand productivity is average for Karelia (average productivity class c. IV.1 with a stock of c. 160-170 m3/ha at an age of 100 years). Spruce forests are normally more productive owing to location in the sites best suitable for forest growth (bilberry habitats, wet depressions, etc.).

Fig. 2. A typical cowberry pine forest over an esker ridge (Lake Tolvajärvi area)

Fig. 3. A typical bilberry spruce forest (Lake Tolvajärvi area)

The amount of spruce undergrowth beneath the canopy of most pine forests (90%) is insufficient for a shift in the species composition to occur. An overwhelming majority of pine forests successfully naturally regenerate upon felling (fig. 4). This process is particularly successful when silvicultural measures are taken to assist natural regeneration - partial soil mineralization and retention of seed trees and patches.

Fig.4. Fragments of pine forest at different stages of stand regeneration upon felling

An exception is large areas of deciduous forest (up to several tens of thousands hectares) formed in place of clear-cut spruce forests, former slashed-&-burnt farmland or selectively cut coniferous areas (fig. 5, 6).

Forest communities have predominantly formed upon fires. They emerged in spontaneous or man-made burns (prescribed burning). Fires in climax forests were very frequent - 1-2 times in a century in dry areas. They were mostly ground fires. Catastrophic fires occurred once in 200 years on average. A uniquely high for north-west taiga of Russia number of fires was recorded in the past from the Loimola village area. They covered even paludified habitats (18 catastrophic fires between 300 and 1800 yrs BP).

Fig. 5. Fragment of a landscape profile with secondary (see fig. 6) and reconstrued primary forests (see fig. 3) in a glacial, hilly-ridge, moderately paludified landscape dominated by spruce habitats (vil. Veshkelitsa area)

Detailed comprehensive description of the structure and dynamics of forests in different landscape types can be found in a series of our publications (Volkov et al., 1990, 1995; Gromtsev, 1993, 2000, etc.).

References

1. Volkov A.D., Gromtsev A.N., Yerukov G.V., Karavaev V.N. et al. Ecosystems of the NW mid-taiga landscapes (structure, dynamics). Petrozavodsk, 1990. 284 p. (in Russian)
2. Gromtsev A.N. Landscape-related patterns in the structure and dynamics of mid-taiga pine forests in Karelia. Petrozavodsk, 1993. 160 p. (in Russian)
3. Volkov A.D., Gromtsev A.N., Yerukov G.V., Karavaev V.N. et al. Ecosystems of the western north-taiga landscapes (structure, dynamics). Petrozavodsk, 1995. 194 p. (in Russian)
4. Gromtsev A.N. Landscape ecology of taiga forests: basic and applied aspects. Petrozavodsk, 2000. 144 p. (in Russian)

Fig. 6. Typical secondary birch forests

Expert: A. Gromtsev
Photos by: I. Gueorgievskiy