Koirajoki Old-Growth Forest Area, Finland

Most of Salamajärvi National Park (62 km2) is mire and previously managed forest but Koirajoki Old-Growth Forest Area (4.6 km2), protected as early as 1912 and today a part of the national park, is untouched by modern forestry; Koirajoki is one of the oldest forests in Central Finland1.

Koirajoki has much open pine forest (photo below), aapa mire and boggy forest. Mesic spruce forests are less extensive. Scots pine (Pinus sylvestris) is the dominant tree. Norway spruce (Picea abies), silver birch (Betula pendula) and downy birch (B. pubescens) are abundant, too. Due to past forest fires, fire-resistant pine also dominates on many moister sites, which are now being invaded by shade-tolerant spruce. Wood volumes are relatively low. The tallest trees (spruces) are slightly over 30 m. Koirajoki is located at approx. 170 m elevation; differences in elevation are small. Average annual temperature is 2.1°C and annual precipitation approx. 570 mm 2. The base rock is granite3. The emblem of the park is the reintroduced wild Finnish forest reindeer (Rangifer tarandus fennicus).

Light sparse pine forest. Also spruce and silver birch. Understory of bilberry (Vaccinium myrtillus), lingonberry (V. vitis-idaea) and common heather (Calluna vulgaris)

Koirajoki Old-Growth Forest Area is the northeastern “extension” of the national park. A hiking trail called “Hirvaan kierros” runs a part of its course through the forest. Off-trail, the forest is partly easy to hike but there are also stone fields covered by moss. Mires, of course, make for slow hiking. Camping is not allowed in the primeval forest; elsewhere in the national park camping is allowed at designated sites and outside the park everywhere under “everyman’s rights”. It is easiest to begin from the Perho–Kinnula road (at 63°18’54.8″N 24°47’29.3″E), along which parking is possible. The southernmost tip of the national park is adjacent to Salamanperä Strict Nature Reserve.



  1. Karvinen, T. (2017): Kansallispuistot: maamme luonnon helmet. Docendo.
  2. https://en.climate-data.org/
  3. Salamajärven suojelualuekokonaisuuden hoito- ja käyttösuunnitelma 2006–2015. 2007. Metsähallitus.