Report - ICP Forests

4. National Survey Reports in 2009 103
4.7 Czech Republic
In 2009 no important change in the development of defoliation for coniferous tree species in
older age categories (stands 60 years old and older) was observed when compared with the
preceding year. Only a slight improvement of particular species was recorded in this category
for Picea abies and Larix decidua which was manifested by decreasing defoliation of trees in
class 2 and an increase in class 1. This trend was reverse for Pinus sylvestris, and no change
occurred for Abies alba.
Distinct improvement showed the younger age categories of coniferous tree species (stands up
to 59 years) where the share of trees showing no defoliation (class 0) increased from 35.0% in
2008 to 41.3% in 2009. This decrease in defoliation applied to spruce, larch and fir (Picea abies,
Larix decidua, Abies alba), whereas when compared to the preceding year, slight increase in
defoliation appeared in the younger pine stands (Pinus sylvestris).
Younger conifers (up to 59 years) were of lower defoliation within the long-term period than
stands with younger broadleaves. In contrast, for older stands (60 years old and older),
defoliation of conifers was distinctly higher than in stands of broadleaves. Important increase in
defoliation was observed in broad-leaved stands (60 years old and older), the share of
broadleaves in class 2 increased from 32.4% in 2008 to 41.0% in 2009. This increase in
defoliation was mainly observed in oak stands (Quercus spp.), whereas the change in other
deciduous tree species was negligible. On the contrary, important improvement occurred in the
younger broadleaves (stands up to 59 years); where the percentage in defoliation class 2 dropped
from 30.1% in 2008 to 14.6% in 2009. This positive change was found in most of the
investigated deciduous tree species of this younger age category, but most distinctly for oak
(Quercus spp.) where the percentage of trees in class 2 decreased from 47.6% in 2008 to 12.0%
in 2009, and at the same time the share of trees in classes 0 and 1 increased to 7.7% and 30.0%,
respectively.
During November, at the end of the vegetation period some forest stands in most forest areas
were mechanically damaged by wet snow. In several forest areas, mainly in spruce stands,
higher occurrence of cambiophagous insects was recorded during the vegetation period. In 2009,
average month temperatures were mostly above average in comparison with the long-term
standard (mainly in April), and the level of average precipitation was mostly above average
mainly in the first half of the year.
In 2009 no important change was recorded for the main pollutants (particulate matters, SO 2,
NO x , CO, VOC, NH 3 ), total emission of most of these substances, despite a certain fluctuation,
has been slightly decreasing for a long time.
4.8 Denmark
The Danish forest condition monitoring in 2009 was carried out in the National Forest Inventory
(NFI) and on the remaining Level I and II plots. Monitoring showed that most tree species had
satisfactory health status. Exceptions were Fraxinus excelsior where the problem with extensive
dieback of shoots has continued. Average defoliation was 42% for all monitored ash trees;
however, this result was strongly influenced by one monitoring plot, where the trees were dying.
But even without those trees, average defoliation was 27%, which is higher than ever recorded
before the appearance of ash dieback.