Forests (the second section)
The forest vegetation of Finland can be divided into three groups mainly by the undergrowth:
1) Dry forests (in Finnish: kuivat kangasmetsät): Scots pine (Pinus silvetris) dominated, dominating dwarf shrubs being heather (Calluna vulgaris) or lingonberry (Vaccinium vitis-idaea) and ground species which are reindeer lichens (Cladonia spp.) and/or red-stemmed feather moss (Pleurozium schreberi). These forests are oligotrophic (poor in nutrients).
2) Moist forests (in Finnish: tuoreet kangasmetsät): spruce- (Picea abies) dominated, bilberry (Vaccinium myrtillus) and feather mosses (Hylocomium splenens) dominating in the undergrowth. Mesotrophic.
3) Herb-rich forests (in Finnish: lehdot): usually dominated by spruce or birch, herbaceous species and certain mosses dominating in the undergrowth.Eutrophic (rich in nutrients).
More details of nothern forests:
Barren heaths (CIT-group = a group of Cladina type) abound in reindeer moss (Cladina spp.) and other lichen. However, there is only a small amount of other kind of undervegetation (twigs, perhaps). The dominant height of pine is approximately 10 m. Along with lichen, also red-stemmed feather moss (Pleurozium schreberi) grows in dry heaths (CT-group = a group of Calluna type). The brush is low but quite abundant, the main twig is often heather (Calluna vulgaris) (or lingonberry, Vaccinium vitis idaea). The dominant height of pine is approximately 15 m.
Along with pine, rather dry heaths (VT-group = a group of Vaccinium vitis idaea type) grow also spruce, silver birch and juniper. The brush is abundant; the main species is lingonberry (Vaccinium vitis idaea). In addition, there grows some hay and grass that tolerate dryness. And feather moss (Hylocomium splendens). However, there is rather little of lichen. Heath humus layer is quite thick.
The dominant tree in fresh heaths (MT-group = a group of Vaccinium myrtillus type) is spruce (dominant height approximately 23 m), but there grows also pine. The brush has great amounts of blueberries (Vaccinium mystillus). Fresh heaths grow hay and grass, and the red-stemmed feather moss cover (Pleurozium, Hylocomium) is solid, but there is very little lichen. A thick heath humus layer.
In grove-like heaths (OMT-group = a group of Oxalis-Myrtillus type), the dominant height of spruce is even 25 m. Leaf trees (e.g. rowan, goat willow, alder) as well as bushes (particularly in the southern Finland) are common. The brush (lingonberry and blueberry) is thick, but thinner in the southern Finland. There is plenty of hay and grass (e.g. wood sorrel, Oxalis acetocella). Along with red-stemmed feather moss, there grows also e.g. Rhytidiadelphus triquetrus. Grove-like heaths are lacking in lichen. The lowest layer of humus is covered with soil.
Distribution of cuckoo bread (Oxalis acetocella) in Fennoscandia. This plant is rather common in the southern herb
rich-forests. However on the coast of Norway cuckoo bread 'climbs' until the north of Lofoten Islands.
Some occurrences arein Kola penincula, too. The southern nature features of the coast of Norway
extend more north than in Finland because of maritime climate. The big picture of cuckoo bread is situated here!
In groves group of Oxalis-Maianthemum type; there are also other types of groves!), grow also some brodleaved trees (very little, though). There are bushes in abundance (e.g. bird cherry, honeysuckle, currants). Herbage is luxuriant, various species. Big-leafed and thin-leafed plant species of groves are characteristic. There are barely any twigs, except maybe blueberry. Moss cover is thin, but there are many species of it. Humus layer is soil mixed with mineral soil.
(Above): Reindeer lichens are abundant in dry Scots pine forests (like this, Calluna-Cladina Type -forest).
There are several different species of reindeer lichens (even in this picture there are at least two).
The reindeer often eats all the lichen from the trees in northern Finland during winter.
In old spruces and pines they are so high that the reindeer cant reach them.
This picture is from Hailuoto -island, where are no reindeers,
but local people are gathering lichens to export (for decoration).
Fire has always been important ecological factor, especially in dry coniferous forests. The forests fires have influenced for example on the succession and tree species relation of forests (see forest fires).
(Above): Crowberry (Empetrum hermaphroditum) is very common in the forest and alpine belts of North Finland.
The flowers are hermaphrodite (you can see the old stamens near the berries). The yield of this crowberry
is better than that (Empetrum nigrum) living in south.
(Above): Dwarf shrubs are abundant in our forests - lingonberry (Vaccinium vitis-idaea) thrives throughout the country
mainly in dry pine forests, although seedlings rarely survive because of the thick moss layer.
Dwarf shrubs are evergreens and thus quite effective savers of energy resources (the stem of the bilberry (V. myrtillus)
is green although it sheds its leaves in the autumn). It is capable of an early start (partly under snow) with the help of the green parts.
The major part of the dwarf shrub mass is often underground (rootstocks, underground runners), safe from frosts, herbivores
and even from forest fires. If the parts above ground are destroyed, there is still enough reserve energy for re-growth.
(Above): Foresfloor vegetation in a HMT forest, where the most common dwarfshrub
is blueberry (V. myrtillus)and the important herb is cow-wheat (Melampyrum pratense).
(Above): Quite a rainforest - at least a dense jungle seen by ant's eyes! This is typical forestfloor
of fresh heath (HMT) with the dwarfshrubs (Vaccinium vitis-idaea, V. myrtillus and V. uliginosum)
and mosses (here Ptilium crista-castrensis, but frequently e.g. Hylocomium splendens).
(Above, left): There are very few herb-rich eutrophic forests in Northern Finland, less than 1% of the forest area.
Most of them are in the calcareous soils in so-called district rich in grass-herb forest (see grass-herb forests).
In the eutrophic forest of the picture (Kainuu, Paljakka) the dominating tree species is spruce,
like often in other Finnish eutrophic forests, too. The typical species in the field layer of this forest are for example
ostrich-fern (Matteuccia struthiopteris) and wood cranesbill (Geranium sylvaticum, it is flowering next to the birch).
Wood-sorrel (Oxalis acetosella) and wood stitchwort (Stellaria nemorum) - both are in the left corner in the picture - are
rare in the Northern Finland.
(Above, right): In northern Finland there are often eutrophic forests near rivers. These forests get every spring
nutrients from the spring floods and thats why they are often fertile. The flood and the flood silt prevent also
the growth of mosses and dwarf shrubs. Deciduous trees, wood cranesbills (Geranium sylvaticum),
globe flower (Trollius europaeus) and clump speed well (Veronica longifolia) are characteristic species for these forests.
Earlier these flood forests have been cleared to flood meadows to get feed for stock.
Some common plant species in the forests of norhtern Finland: crowberry (Empetrum hermahroditum), wavy hair-grass (Deschampsia flexuosa), cranesbill (Geranium silvaticum), oak fern (Gymnocarpium dryopteris), as well as herbaceus cornel (Cornus suecica). Blueberry (Vaccinium myrtillus) thrives as well in dry heaths, likewise whortleberry (Vaccinium uliginosum) and marsh ledum (Ledum palustre). In addition some mosses, e.g. Dicranum fuscescens, many lichens, e.g. Cladonia alpestris and Neproma arcticum.
Species, which are not common in the north: may lily (Maianthemum bifolium), stone bramble (Rubus saxatilis), forest smallreed (Calamagrostis arundinacea), wood-sorrel (Oxalis acetocella), lily of the valley (Convallaria majalis), raspberry (Rubus idaeus), strawberry (Fragaria vesca) and male fern (Dryopteris filix-mas).
Spruce (Picea abies) and mountain birch (Betula pubescens var. pumila) drive in the northern forestline.
Certainly the spruce is here in Saariselkä mountain area very close to the northernmost site of spruce.
Pine (Pinus sylvestris) is most northerly existing conifer tree in Finnish Lapland.
Here it grows alone in fjeld area of Saariselkä (Finnish Lapland). Pine suffers there
both frosts, storms and snowweight (in Finnish: tykky)...
The snow cover protects the organisms from frost and drought; the plants are also protected from the herbivores. Under a snow cover of 50 centimetres it is rarely colder than -5°C. But under the snow it is dark, so photosynthesis is not possible. When the Lapland snow finally melts in spring, the long northern day and usually also the thermal summer have already begun... (see the effective temperature sum!). The actual growing season is short!
The trees on the timberline live to the extremities tolerance: the growing season is short, growth and reproduction is difficult, desiccation is a threat and in winter the crown snow load (tykky) breaks trees and branches. In the picture the wind-made figures on the snow are also visible. See also: snow on trees in Iso Syöte!