baumzaehlen - Primeval Forests & Their Trees

©2017copyright christoph hase

Urho Kekkonen National Park, Finland


This is the second largest (2550 km2) national park in Finland. Altitude ranges from 113 metres to 718 metres; annual precipitation is 400–500 mm and average annual temperature at low altitudes approx. -1°C. A large part of the park is above the forest limit but the park also contains extensive Opens internal link in current windowPinus sylvestris (Scots pine) and Opens internal link in current windowBetula pubescens (downy birch) forests and in the southeast Opens internal link in current windowPicea obovata (Siberian spruce) forests. The forests are low and open but the numerous grey dead trees both standing and fallen, gnarly pines and open vistas have their own beauty. Tree species diversity is low and most species are easy to identify. P. obovata has a very narrow crown, as do the northern races of P. sylvestris, though less markedly so than the spruce. The narrow crowns increase the efficiency of light interception at the low sun angles1 and reduce snow loads2. Unlike in many other boreal regions, in Fennoscandia a broadleaf tree, B. pubescens, extends beyond the coniferous species in response to the oceanic climate3. At higher elevations B. pubescens is mainly variety pumila (arctic downy birch), which intergrades to var. pubescens at low elevations. Variety pumila has arisen from the hybridization of var. pubescens and (sub-)shrub Betula nana (dwarf birch) 4. Features inherited from B. nana have made this tree-like birch suited for Lapland’s harsh conditions5. Other regions where Betula reaches forest limit include Asia’s east coast (see Opens internal link in current windowShiretoko National Park), the northern Ural, the Himalayas and the Caucasus (see Opens internal link in current windowLagodekhi Strict Nature Reserve); Alaska’s Opens internal link in current windowAlnus viridis subsp. sinuata (Sitka alder) stands are ecologically homological, too5.

 

The park is a popular hiking destination but so large that solitude is guaranteed in more remote parts. Undergrowth is sparse and off-trail hiking generally very easy; there are also plenty of hiking routes. Not all the forests of the park area are old-growth: there were large-scale fellings up to the 1970s, prior to the establishment of the park6. The park area is also used for the grazing of large herds of reindeer, which has a marked negative impact on the lichen cover of the drier forests. Free camping is allowed in more remote areas. There are also free wilderness huts. In July, mosquitoes can be very annoying.

 

References:

 

1       Kuuluvainen, T. (1992): Tree architectures adapted to efficient light utilization: is there a basis for latitudinal gradients? Oikos 65: 275-284.

2       Petty, J. A. & Worrell, R. (1981): Stability of coniferous tree stems in relation to damage by snow. Forestry 54: 115-128.

3       Sirois, L. (1992): The transition between boreal forest and tundra. – In Shugart, H. H. et al. (eds.) A System Analysis of the Global Boreal Forest. Cambridge.

4       Väre, H. (2001): Mountain birch taxonomy and floristics of mountain birch woodlands. – In Wielgolaski, E (ed.): Nordic Mountain Birch Ecosystems. Man and the biosphere series Vol. 27. UNESCO-Paris and The Parthenon Publishing Group.

5       Juhanoja, S. (1995): Opens external link in new windowMonimuotoinen tunturikoivu. Sorbifolia 26(4).

6       Urho Kekkosen kansallispuiston hoito- ja käyttösuunnitelma (2001). Metsähallitus.

 

Official site:

 

http://www.nationalparks.fi/en/urhokekkonennp

 

Pinus sylvestris (Scots pine) forest.
Betula pubescens var. pumila (arctic downy birch) forest. Also Picea obovata (Siberian spruce), right background.
Pinus sylvestris (Scots pine) forest along Suomujoki (elev. 160 m).
Betula pubescens var. pumila (arctic downy birch) - Pinus sylvestris (Scots pine) woodland. At the small lake (Pikku Luirojärvi, elev. 321 m) Picea obovata (Siberian spruce) stand.
Paratiisikuru (elev. 400 m). On the slope Betula pubescens var. pumila (arctic downy birch) woodland.