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Deadwood (4.5)
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| Deadwood left in the forest after a felling helps the survival of certain species on the site across tree generations. |
Certain forest organisms rely on dead or decaying wood for
their survival. Many of these species are threatened. According
to the latest report on threatened species, published in 2010,
the reduction in decaying wood is the main factor threatening
the survival of 164 species, representing 11% of all threatened
species.
According to NFI 10 (2004–2008), the average volume of dead
and decaying wood with thickness exceeding 10 cm in forests
(commercial forests and nature conservation areas) is 3.3 cubic
metres per hectare in southern Finland and 9.0 cubic metres per
hectare in northern Finland. Compared to the previous inventory
(NFI 9, 1996–2003), the amount of decaying wood has increased
in southern Finland and decreased in northern Finland. Oldgrowth
forests in natural state may have 60–120 cubic metres
of dead and decaying wood per hectare, but the amount varies
a great deal depending on the fertility of the site, the development
state of the forest and natural disturbances.
The amount of deadwood in forests will increase as retention
trees are left standing in regeneration sites to maintain biodiversity
and the amount of decayed wood in the forest. In 1995–
2010, the average total volume of green trees left standing in
regeneration fellings in private forests and the forests of the forest
industry companies was 3.1 cubic metres per hectare. The
volume of deadwood in felling sites varied from 1 to 1.4 cubic
metres per hectare. An average of 11 green retention trees were
left standing in each felling site.
Table 4.5. Volume of deadwood in forest and low productive forest, 2008.
Regional districts of the Finnish Forestry Centre
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Dead trees |
Standing m³/ha |
On the ground m³/ha |
Total m³/ha |
Conifers |
Broadleaved |
Total |
Conifers |
Broadleaved |
Total |
Conifers |
Broadleaved |
Total |
Whole country |
1,3 |
0,3 |
1,7 |
3,5 |
0,6 |
4,2 |
4,8 |
0,9 |
5,9 |
Southern Finland |
0,9 |
0,3 |
1,2 |
1,6 |
0,4 |
2,1 |
2,5 |
0,7 |
3,3 |
Northern Finland |
1,8 |
0,4 |
2,2 |
5,9 |
0,7 |
6,8 |
7,7 |
1,1 |
9,0 |
Source: Finnish Forest Research Institute, National Forest Inventory
Under forest certification criteria, at least 5–10 dead or live retention
trees with a breast height diameter of over 10 centimetres
must be left standing in certified regeneration sites. Also individual
fallen trees are nowadays often left in the forest. Broadleaves
of slight economic value are left uncut in all fellings.
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