baumzaehlen - Primeval Forests & Their Trees

©2019copyright christoph hase

Pyhä-Häkki National Park, Finland

Half of this park (13 km2) is forest and half bog. Most of the forest has grown without noticeable human disturbance1.


Before the introduction of modern fire suppression, the fire return interval was approximately 52 years 2. The last fire in the park was in 1921 1. However, these fires were mostly of human origin; particularly in the period which began at the end of 1500’s and ended about 1850, the fire interval was much shorter than the natural one, which had been 200–500 years 3. Gap-dynamics and surface fires were the dominant natural disturbance regime unlike, for example, in western Siberia and central Canada (see Opens internal link in current windowPrince Albert National Park), where crown fires are dominant4.


Opens internal link in current windowPinus sylvestris (Scots pine) and Opens internal link in current windowPicea abies (Norway spruce) dominate. P. sylvestris is present everywhere from bogs to the driest areas; it is the most drought-tolerant and nutrient-stress-tolerant of the Eurasian boreal tree species5, and the thick bark of large individuals protects them from fire4. However, its cones are not serotinous like cones of the North American species Opens internal link in current windowP. banksiana (jack pine) and Opens internal link in current windowP. contorta (lodgepole pine) 4. On dry soils, it maintains its dominance, but in the absence of fire, fire-intolerant and more shade-tolerant5 P. abies is invading mesic soils. The dark P. abies stands contrast with light P. sylvestris stands. The other large tree species of the park are Opens internal link in current windowBetula pendula (silver birch), Opens internal link in current windowB. pubescens (downy birch), Opens internal link in current windowPopulus tremula (common aspen) and on a few wet sites Opens internal link in current windowAlnus glutinosa (black alder). The smaller trees are Opens internal link in current windowAlnus incana (grey alder), Opens internal link in current windowSalix caprea (goat willow) and Opens internal link in current windowSorbus aucuparia (European rowan). You may have difficulties distinguishing between B. pendula and B. pubescens but other tree species are very easy to identify.

The park is located at an elevation of approx. 160–190 metres. Annual precipitation is 600 mm and average annual temperature 2.5°C. Off-trail hiking is very easy, apart from bogs. Camping is not allowed in the park but possible outside the park boundaries, like everywhere in Finland, Sweden and Norway.





1       Pyhä-Häkin kansallispuisto. Metsähallitus.

2       Karvinen, T. (2017): Kansallispuistot: maamme luonnon helmet. Docendo.

3       Keto-Tokoi, P. & Kuuluvainen, T. (2010): Suomalainen aarniometsä. Maahenki.

4       Shorohova, E., Kneeshaw, D., Kuuluvainen, T. & Gauthier, S. (2011): Opens external link in new windowVariability and Dynamics of Old-Growth Forests in the Circumboreal Zone: Implications for Conservation, Restoration and Management. Silva Fennica 45(5).

5       Nikolov, N & Helmisaari, H. (1992): Silvics of the circumpolar boreal forest tree species. In Shugart, H. H. et al. (eds.): A Systems Analysis of the Global Boreal Forest, 1384. Cambridge.


Official site:


Picea abies (Norway spruce) forest. Also Populus tremula (common aspen), extreme left, and dead Betula sp. (birch, white trunk), left. On forest floor Vaccinium myrtillus (bilberry). Elev. 170 m.
The tallest and most heavily wooded stand of the park with Pinus sylvestris (Scots pine, with coarse lower bark and reddish upper bark) and Picea abies (Norway spruce), both up to 35 m tall. Also shrub-like Sorbus aucuparia (European rowan). Elev. 170 m.
Forest on dry soil with Pinus sylvestris (Scots pine, foreground and red trunks in the background), Picea abies (Norway spruce, with dark foliage) and Betula pendula (silver birch, with white bark). Elev. 175 m.
Pinus sylvestris (Scots pine) forest at 175 m regenerated after wildfire in 1855. Also Picea abies (Norway spruce) sapling, right.
Kotajärvi at 165 m. Pinus sylvestris (Scots pine) forest. Left also Picea abies (Norway spruce); right also small Betula pubescens (downy birch).
The largest tree of the park, Pinus sylvestris (Scots pine) called "Iso puu", germinated in 1518, now dead.
One of the largest living trees of the park, Pinus sylvestris (Scots pine). Also small Sorbus aucuparia (European rowan), left.
Boggy forest with Alnus glutinosa (black alder, dark trunks), Betula pubescens (downy birch, white trunks), Picea abies (Norway spruce, foliage on the right) and Pinus sylvestris (Scots pine, red trunks, background) at 165 m.
Alnus incana (grey alder), foreground. Also Pinus sylvestris (Scots pine), left, and Picea abies (Norway spruce), right.
Betula pubescens (downy birch) in Picea abies (Norway spruce) forest at 165 m.
Betula pendula (silver birch) in Picea abies (Norway spruce) forest.
Stand of Betula pendula (silver birch, 2., 4. and 5. trunk from left) and Populus tremula (common aspen, the other grey trunks) at Kotajärvi. Also Picea abies (Norway spruce, background) and shrub-like Juniperus communis (common juniper). Elev. 165 m.
Salix caprea (goat willow) in Picea abies (Norway spruce) forest.
Creek called Kotapuro at 164 m. Picea abies (Norway spruce) forest. Also white Betula pubescens (downy birch), and shrub-like Sorbus aucuparia (European rowan, centre) and Frangula alnus (alder buckthorn, right).
Bog called Kotaneva at 165 m. In the background, the even-aged Pinus sylvestris (Scots pine) forest of the image 5.
All the tree species of the park.