The deviations between the countries in the proportion of coniferous forests cannot be explained by different thresholds used in the classification of different types of forests. For example, to be classified as coniferous, a forest stand in Finland has to have over 75% of its timber volume in coniferous trees; the correspondent threshold in Sweden is 70%, and in Russia the tree-species dominance is calculated on the basis of the dominant canopy-layer. Thus, despite the Finnish forests having the highest threshold to become classified as coniferous, they still have the highest proportion of their total area classified as coniferous. In deciduous forests Finland having the highest threshold may have some impact, as the proportion of deciduous forests in the Finnish study area is significantly lower than in the two other countries.
Differences in silvicultural practices offer a very obvious explanation for deviations between Finland and Russia. In Sweden and Finland it is a common practice to regenerate forests for pine or spruce (and to a lesser extent for birch), either by planting, sowing or natural seeding from retention trees left specifically for this purpose. Majority of these young stands then develop a mixed (conifer-deciduous) tree-species composition though, but in the pre-commercial thinnings the proportion of less-wanted species (most commonly the deciduous species) in the stand is significantly reduced. In Russia neither active regeneration measures Table 15. Forest coverage in the Russian study area.
Murmansk Karelia Arkhangelsk Nenets Komi Russia
km2 % of region km2 % of region km2 % of region km2 % of region km2 % of region km2 % of region
All coniferous forest 20 469 14,3 54 381 31,5 99 074 32,1 7 455 4,2 158 262 37,9 339 641 27,9
Spruce-dominated coniferous forest 7 314 5,1 9 892 5,7 57 695 18,7 7 019 4,0 110 927 26,6 192 847 15,8
All pine-dominated coniferous forest 13 155 9,2 44 489 25,8 41 380 13,4 436 0,2 47 335 11,3 146 795 12,0
Pine-dominated coniferous forest on mineral soil 12 935 9,0 36 110 20,9 29 636 9,6 436 0,2 38 108 9,1 117 226 9,6
Pine-dominated coniferous forest on peatland 220 0,2 8 379 4,8 11 743 3,8 0 0,0 9 226 2,2 29 568 2,4
Mixed forest 24 028 16,8 29 519 17,1 61 283 19,9 2 697 1,5 104 352 25,0 221 878 18,2
Deciduous forest 27 714 19,3 21 486 12,4 64 853 21,0 2 248 1,3 57 654 13,8 173 955 14,3
All forest 72 211 50,3 105 386 61,0 225 210 73,1 12 401 7,0 320 268 76,7 735 475 60,4
after final fellings nor the pre-commercial thinnings of young stands have so far been a very common or established silvicultural practice, and thus the young stands there tend to develop and then retain their (often deciduous-dominated) composition, and later develop into mixed forests.
The significance of the silvicultural practices is confirmed when comparing the proportion of HCV forests in the coniferous forests in Finland and Russia.
Of all the coniferous forest in the Russian study area 47,4% is classified as HCVFs (and using the Nordic criteria the figure would be even higher), whereas the corresponding figure in the Finnish study area is 28,9%, leaving 70,1% of the coniferous forests there into the class of more or less managed forests (even though the figures for HCV forests may be underestimates). In spruce-dominated coniferous forests the difference between Russia (62,9%) and Finland (40%) is significant as well, but in the pine-dominated coniferous forests the figures (27,1%
for Russia and 27,6% for Finland) are almost equal. Considering that 1) In the natural conditions the proportion of the coniferous forests in the total amount of forests would be more or less equal in Sweden, Finland and Russia, and 2) That the ratio of the total amount of spruce-dominated coniferous forests to the total amount of pine-dominated coniferous forests in the Finnish study area is appr. 1:9 and in the Russian study area appr. 1: 0,75, the difference in the proportions of the coniferous forests in the total amount of the forests are mainly due to the amount of managed pine-dominated forests in Finland and the silvicultural practices applied in these forests.
However, this is not the whole truth even considering the deviations between the Finnish study area and those parts of the Russian study area that are located in the vicinity of Finland in the Fennoscandian Shield area (the Republic of Karelia, Murmansk Region), but especially does not explain the deviations between the Finnish and the Swedish study area at all, as the silvicultural practices in the two latter ones are more or less similar to each other. One possible explanation is related to timing: Outside the rather densely populated lowland areas near the coast of Bothnian Bay and in the lower Tornio (Torneå) River valley, where the vast majority of mineral soil forests have been in more or less intensive forestry use for a long time, Sweden and Finland have taken somewhat different paths during the last decades.
During and after WW II, large scale industrial clearcuttings were carried out in
Murmansk Karelia Arkhangelsk Nenets Komi Russia
km2 % of region km2 % of region km2 % of region km2 % of region km2 % of region km2 % of region
All coniferous forest 20 469 14,3 54 381 31,5 99 074 32,1 7 455 4,2 158 262 37,9 339 641 27,9
Spruce-dominated coniferous forest 7 314 5,1 9 892 5,7 57 695 18,7 7 019 4,0 110 927 26,6 192 847 15,8
All pine-dominated coniferous forest 13 155 9,2 44 489 25,8 41 380 13,4 436 0,2 47 335 11,3 146 795 12,0
Pine-dominated coniferous forest on mineral soil 12 935 9,0 36 110 20,9 29 636 9,6 436 0,2 38 108 9,1 117 226 9,6
Pine-dominated coniferous forest on peatland 220 0,2 8 379 4,8 11 743 3,8 0 0,0 9 226 2,2 29 568 2,4
Mixed forest 24 028 16,8 29 519 17,1 61 283 19,9 2 697 1,5 104 352 25,0 221 878 18,2
Deciduous forest 27 714 19,3 21 486 12,4 64 853 21,0 2 248 1,3 57 654 13,8 173 955 14,3
All forest 72 211 50,3 105 386 61,0 225 210 73,1 12 401 7,0 320 268 76,7 735 475 60,4
forest 30-80 years of age (results of the national forest inventory in http://www.
paikkatietoikkuna.fi/web/fi/kartta), meaning that they (when managed) already have been through silvicultural operations. It has been a common practice to significantly reduce the proportion of the deciduous trees in the managed forest stands. The result is most dramatically visible in the watershed areas of central Lapland (map 10), where non-mature pine-dominated forests rule the forest landscape. In the Swedish study area, on the other hand, the industrial commercial loggings have proceeded more systematically starting from coastal areas and the river valleys and moving step by step towards harder-to-access areas on higher grounds and closer to the fells. In the Swedish part of the study area, 4,8% of the forests are classified as young stands (including recent final-felling areas), and as such classified as mixed forest in this study. It is highly likely that somewhere in near future, due to dominant silviculture practices, the majority of these will turn into coniferous forest, thus evening up the current difference in proportion of coniferous forests in the Swedish and Finnish study areas.
When it comes to the most northwestern parts of the Russian part of the study area, in the northern part of the Republic of Karelia, the industrial clear-cuttings have in the 1900’s and until today more or less systematically proceeded from the Murmansk railroad in the east towards west, creating vast post-cutting forest landscapes dominated by secondary mixed or deciduous forests, and leaving only the previously most intact forest landscapes and tracts (most of them bordering to Finland) plus some semi-natural forest areas connecting them to represent coniferous forest. In the western part of the Murmansk Region, in addition to large scale commercial logging, vast forest fires have been a significant factor in modifying the forest landscape towards an increased proportion of mixed and deciduous forest, whereas intensive monitoring and effective prevention of wildfires has all but eliminated fire as an factor in forest regeneration in Sweden and Finland.
Another very probable factor contributing to deviations in the forest landscape in adjacent areas in Sweden, Finland and Russia, is the varying role of domesticated reindeer (Rangifer tarandus domesticus) and wild reindeer (both Rangifer tarandus tarandus and Rangifer Tarandus Fennicus). The leaves and sprouts of deciduous trees are a part of reindeer´s summertime diet (Nieminen 2014, Helle et al. 1998), and thus the reindeer may have a significant impact on regeneration of the deciduous trees. This applies both natural and managed forest. In Finland the reindeer husbandry area covers 122 936 km², or 76,4% of the Finnish study area, and is completely located within the study area limits.
The size of the summer herd is app. 300 000 heads (2,4 heads / km²) (http://
jounikitti.fi/suomi/porot/porotalous.html), which creates a rather intensive grazing pressure. In Sweden the reindeer husbandry area covers the whole study area (165 110 km²) plus vast areas south of it; the summer herd in the study area being app. 317 000 heads (1,9 heads / km²) strong (https://www.sametinget.se/
statistik/renhjorden) – significantly less per km² than that in Finland. In Finland the annual grazing cycle is confined to the grazing areas of each of the 54 local reindeer herders’ associations, whereas in the Swedish study area, on vast areas between the Bothnian Bay coastline and the foothills of the Scandes, the summer grazing of reindeer is banned, and only wintertime grazing is allowed (http://
jounikitti.fi/suomi/porot/norjaruotsi.html., http://www.nordregio.se/Global/
Publications/Publications%202015/Teksti_finnish.pdf). Below the mountain birch forests in the Scandes, the difference in the amount of mixed forests and deciduous forests between the year-round grazing areas and winter-only grazing areas in the Swedish study area is rather well visible. The distinction to the Finnish areas
south of the mountain birch belt is also obvious, with the exception of the area just northwest of the Bothnian Bay, which does not belong to the Finnish reindeer husbandry area.
In the northwestern part of the Russian study area, there is reindeer husbandry only in the central and eastern part of the Kola Peninsula in Murmansk Region.
The reindeer husbandry areas both in Sweden and Finland would be natural territory for the mountain reindeer (Rangifer tarandus tarandus) and the forest reindeer (Rangifer tarandus fennicus), but both subspecies are extinct in this area.
In the Finnish study area wild forest reindeer live in areas south of the reindeer husbandry area, as well as in the adjacent areas in the Republic of Karelia in the Russian study area, but the remaining herds are small. In Murmansk Region there still is – depending on source – 2000-7000 wild mountain reindeer left (Nieminen 2014, http://senc.hum.helsinki.fi/wiki/Peura). In any case this means serious under-grazing compared to natural conditions, and has led to a situation where the proportion of both the mixed and the deciduous forests in the forest landscape is unnaturally high. The difference as compared to the Finnish side of the border, where the proportion of deciduous trees may be unnaturally low due to intensive reindeer grazing, becomes very dramatic.
Without much more thorough GIS-analysis it is impossible to accurately evaluate, how big part of the deviations in the forest landscape between the countries displayed on the land cover maps is just a result of differing national land cover-systems, and how much of the differences is real. But as many of these deviations are directly visible also on satellite images, it is rather safe to assume that significant differences occur also in reality.
5.2