Tree species composition (4.1)
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| Figure 4.1a. Tree species dominance on forest land, 2009.
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| Figure 4.1b. Pure and mixed forest stands on forest land, 2009.
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| Mixed stands are preferred especially in more productive sites
where the natural characteristics of a site provides favourable
conditions for growth. The share of broadleaves is often 10-30%
of the volume of the stock. |
The number of indigenous tree species in Finland is small: four
conifers and 27 broadleaved species of trees, bushes or small
trees. Some of the broadleaves have a very narrow area of distribution.
Many sites are dominated naturally by just one species,
such as pine in upland forests. Mixed stands and predominance
of broad-leaves are common in fresh mineral soil sites
and upland forests with grass-herb vegetation. The most common
species growing in mixed stands is downy birch.
Pine predominates on 67% of forest land, spruce on 22% and
broadleaves on 11%. Broadleaves, which are important to forest
biodiversity and the soil and grow mostly in mixed stands,
account for 20% of the total volume of growing stock, which
is clearly more than the total area of predominantly deciduous
stands.
Tree species composition changes slowly. Since the beginning of
the 1950s, the share of pine dominated stands has increased as
a result of regeneration with pine. The most significant change is
the reduction of the area of predominantly deciduous stands by
a half in southern Finland. The species composition has changedless in terms of growing stock volume than in terms of species
predominance.
Pure stands17 account for 55% of all forest land, stands with
some mixing18 account for 31% 19, and actual mixed stands account
for 13%.
Conifers (4)
- Scots pine (Pinus sylvestris)
- Norway spruce (Picea abies)
- Common juniper (Juniperus communis)
- European yew (Taxus baccata)
Broadleaves (27)
- Silver birch (Betula pendula)
- Downy birch (Betula pubescens)
- Common alder (Alnus glutinosa)
- Speckled alder (Alnus incana)
- Aspen (Populus tremula)
- European rowan (Sorbus aucuparia)
- Oakleaf mountain ash (Sorbus hybrida)
- Swedish mountain ash (Sorbus intermedia)
- Swedish rowan (Sorbus teodori)
- Bird cherry (Prunus padus)
- Littleleaf linden (Tilia cordata)
- Norway maple (Acer platanoides)
- Common oak (Quercus robur)
- European ash (Fraxinus excelsior)
- Wych elm (Ulmus glabra)
- European white elm (Ulmus laevis)
- Crab apple (Malus sylvestris)
- Buckthorn (Rhamnus catharticus)
- Glossy buckthorn (Rhamnus frangula)
- Hawthorn (Crataegus monogyna)
- Hawthorn (Crataegus rhipidophylla)
- Goat willow (Salix caprea)
- Bay-leaf willow (Salix pentandra)
- Black maul (Salix triandra)
- Dark-leaved willow (Salix myrsinifolia)
- Boreal willow (Salix borealis)
- Pyrolavide (Salix pyrolifolia)
Source: Hämet-Ahti, L. et al. 1992. Suomen puuja
pensaskasvio (Woody Flora of Finland). Finnish
Dendrological Society.
Links
17 Pure stand: the proportional share of the dominant species of the volume
(in seedling stands, the proportional share of the number of viable seedlings)
is over 95%.
18 Stand with some mixing: the proportional share of the dominant species of
the volume (in seedling stands, the proportional share of the number of viable
seedlings) is between 75–95%.
19 Mixed stand: the proportional share of the
dominant species of the volume (in seedling stands, the proportional share of
the number of viable seedlings) is below 75%. |
