Report - ICP Forests

4. National Survey Reports in 2009 105
4.10 Finland
In Finland the integration between ICP Level I and NFI has been accomplished in 2009 by
moving the extensive level (level I) ICP plots to the present NFI network, i.e. to the permanent
plots established during the 9 th NFI in 1996-2003. The sampling design of the NFI (NFI 11) is a
systematic cluster sampling. The distance between clusters, the shape of a cluster, the number of
field plots in a cluster and the distance between plots within a cluster vary in different parts of
the country according to spatial variation of forests and density of road network. Principally,
every fourth cluster is marked as a permanent cluster. The same permanent plots will be
assessed in five- year intervals. All tallied dominant and co-dominant Norway spruce, Scots pine
and birch trees are assessed, and results from 6 pre-selected permanent plots from each cluster
are reported to the ICP and to the EU.
Please note that because Finland is using a completely new plot design from 2009 onwards, the
results from 2009 are not directly comparable with the results from previous years.
The 2009 forest condition survey was conducted on 886 permanent sample plots. Of the 7182
trees assessed in 2009, 56.4% of the conifers and 67.2% of the broadleaves were not suffering
from defoliation (leaf or needle loss 0-10%). The proportion of slightly defoliated (11- 25%)
conifers was 33.6%, and that of moderately defoliated (over 26%) 9.9%. For broadleaves the
corresponding proportions were 28.1% and 4.7%, respectively. In general, the average treespecific
degree of defoliation was 11.9% in Scots pine, 18.3% in Norway spruce, and 13.4% in
broadleaves (mainly Betula spp.).
The proportion of discoloured Scots pine trees (discolouration > 10%) was 1.2%, the
corresponding proportion for Norway spruce was 7.3% and for broadleaves 2.4%. Most of the
discoloured spruces or pines belonged to the discolouration class 10 to 25%, and moderate or
severe discolouration was rare. The most frequent discolouration symptoms on Scots pine was
browning of needles of all ages. In Norway spruce the most common symptoms was yellowing
and yellow tips and the youngest needles.
Abiotic and biotic damage was also assessed in connection with the large-scale monitoring of
forest condition. 33.1% of the Scots pines, 34.5% of the Norway spruces and 25.2% of the
broadleaves were reported to have visible/ symptoms attributed to abiotic or biotic damaging
agents. Gremmeniella abietina (7.4 %), Neodiprion sertifer (4.9%) and Tomicus spp. (3.5 %)
were the most abundant biotic damaging agents in pine, and Chrysomyxa ledi (11.2 %) and
Heterobasidion sp. (2.1%) in spruce. In broadleaves, undetermined defoliating insects (3.6% of
the trees) were the most common group of biotic/ abiotic causes.
According to the observations of the Forest Damage Information Service, Neodiprion sertifer
had vast mass outbreaks in pine forests, mainly in southern Ostrobothia and in mid-Finland.
Sporadic damage was also found in the southern parts of the country. The damaged area was
estimated to be over 350 000 hectares.