Musta-Kotinen Forest, Finland

Only 15 ha of the reserve “Kotinen Primeval Forest” (232 ha) really is primeval forest; this core area has been called Musta-Kotinen Forest, as its northwestern end is a point jutting from the southern shore of Lake Musta-Kotinen1. The virgin forest extends along a low ridge to the southwestern side of Lake Valkea-Kotinen, including both the northeastern and the southwestern slope and the southwestern shore of Valkea-Kotinen. There are no clear signs of human impact; probably the core area is untouched except single cut trees along the path by the southwestern shore of Valkea-Kotinen1. The area was protected by the forest administration as early as the 1920s as an example of a pristine forest stand1. The importance of the forest derives from its location in southernmost Finland, where almost nothing has remained untouched. Outside the core area, the reserve consists of younger forest and even a clearcut. Elevations reach from 154 m (the shore of Musta-Kotinen) to about 170 m. Average annual temperature is 3.6°C and annual precipitation approx. 640 mm 2. The bedrock consists of gneiss3.

Musta-Kotinen is magnificent dim mesic Norway spruce (Picea abies) forest (photo below). Spruce form 70% of the forest1. The proportion of common aspen (Populus tremula) is exceptionally high; together with silver birch (Betula pendula) it forms 20% of the forest1. The proportion of Scots pine (Pinus sylvestris) is here only 10% 1. The canopy height is mostly around 30 m but the tallest spruces rise above that, with two near Lake Musta-Kotinen reaching about 40 m, and well visible from the southwestern shore. The taller of these was 40.5 m in 2020, a remarkable height in Finland, the tallest spruce (and the tallest native tree) in Finland being 45 m, only 12 km away4. Wood volume is exceptionally high for a boreal forest: 600–700 m3/ha 5. The average age of the dominant canopy layer is 150–250 years, with some big pines more than 300 years old1 (photo right). Small windthrow gaps occur here and there. The amount of dead wood is remarkably high, consisting of trunks and branches in variable stages of decay1. There are also signs of several, more than 100 years old forest fires on the living pine trunks1. Pine is present practically only as old trees and will gradually disappear if no forest fire gives it a chance to regenerate. The ridge is so low that the forest character barely changes; there are slightly more pine and the spruce are smaller on the southwestern slope and on the ridge. The undergrowth mostly consists of bilberry (Vaccinium myrtillus) and mosses. False lily (Maianthemum bifolium) is abundant in places.

Mesic spruce dominated forest with some pine (with rough bark) and aspen (big tree, foreground)

Two paths lead to the borders of the virgin forest: The first, actually a small road at its beginning, starts from the road “Ruuhijärventie”, near the place “Pikkuaho”. On maps it has only been marked to near the southwestern shore of Musta-Kotinen, but in reality it continues as a small path to the virgin forest border. The other path starts from “Koivusuontie” south of Valkea-Kotinen and leads to the southern and southwestern shore of Valkea-Kotinen. Note that the path from “Ruuhijärventie” (near the place “Vahtervehmas”) to Valkea-Kotinen, marked on maps, is now overgrown and impossible to walk along in many places. In the old-growth forest, fallen trees and rocks hinder the hiking in places but generally it is fairly easy. Apart from a few study plots, there are no human signs in the forest. However, the area is small, in particular narrow. Nor is it far from the closest road, approx. 500 m as the crow flies, so some traffic noise can be heard. The reserve is adjacent to the popular but unprotected Evo Hiking Area with its marked trails, fire places and lean-to shelters; with logging, hunting etc. allowed here.



  3. Hatakka, T. (2011): Maaperän ja pohjaveden geokemiallinen koostumus Valkea-Kotisen alueella. In Vuorenmaa, J., Arvola, L. & Rask, M.: Hämeen ympäristö muutoksessa: Kaksikymmentä vuotta ympäristön huippututkimusta Valkea-Kotisen alueella. Suomen ympäristökeskus.
  4. Finnish Forest Research Institute, pers. comm. (2020)
  5. Kallonen, S. (2011): Kotisten luonnonsuojelualue. In Vuorenmaa, J., Arvola, L. & Rask, M.: Hämeen ympäristö muutoksessa: Kaksikymmentä vuotta ympäristön huippututkimusta Valkea-Kotisen alueella. Suomen ympäristökeskus.