Press
Release ECE/TIM/99/4
Geneva, 30 December 1999
CATASTROPHIC STORMS HIT
EUROPE’S FORESTS:
DANGERS OF AFTERSHOCKS!
Tempestuous winds
ravaged forests in Europe on 26 December and again on 28 December 1999 leaving a
morbid trail of fallen and broken trees. "The tempests will have disastrous effects
not only on forest but also on the timber markets as well as on wildlife" says Edward
Pepke, Forest Officer at the United Nations Economic Commission for Europe (UN/ECE),
"but aftershocks may even be more disastrous. In particular there is a risk of insect
infestation which may further harm forests."
The windthrow was accentuated by the
preceding weeks of heavy rainfall and unseasonably warm temperatures. Soils in many
mid-European forests as well as urban and cultivated areas were unfrozen and waterlogged
rendering the root systems inefficient against the high winds. Deep-rooted pines and
hardwood species were often broken while shallow-rooted species like fir and spruce were
more frequently uprooted. However many trees found little resistance in the muddy soils
and succumbed to the two successive storms.
At this time soon after the storms, it is
impossible to accurately assess the magnitude of the damage. However early reports
indicate record levels of damages. In Switzerland, for example, the Office fédéral de
l’environnement, des forêts et du paysage has estimated that approximately 8.4
million cubic metres (m3) of timber has been downed. This is twice that felled by the
disastrous storms in 1990 (4.3 million m3).
Estimates for damages in other countries
have not yet been received because of inaccessibility of mountain forests due to road
closures by fallen trunks, branches and deep snow, combined with the end-of-year holiday
period. It is known that in addition to Switzerland forests in France, Germany and Belgium
sustained considerable damage.
Unfortunately many mountain forests, which
were destroyed, were planted and managed specifically for avalanche control. These forests
on steep slopes and thin soils will take decades to re-establish. Already avalanches have
occurred from the heavy snows at altitude and the loss of these protective forests could
aggravate the hazardous situation.
All forests have a protective watershed
protection function too. However the ability of mountain forests to absorb and regulate
water flow can be disrupted by the windblow, potentially leading to rapid water runoff.
Wildlife habitat has been ravaged in
certain areas and wildlife biologists will be assessing the impacts and damages to
populations of birds and animals. Current forest management practices prescribe leaving
some quantities of dead trees in harvested sites. These trees are nesting sites for birds
and animals as well as important sources of biodiversity. However the vast quantities of
dead and dying trees could have negative consequences.
Following the 1990 windblow there were
incidents of insect infestation on the dead and dying timber. Worm holes and associated
stain from fungal and bacterial attack can render structural- and furniture-grade wood
useless. Not only are the fallen trees at risk, but also the adjacent trees which can be
hosts for the parasites too. Therefore many dead trees must be removed to avoid a breeding
ground for unwanted infestations.
Clean-up of windthrown timber depends on
access to the forest stands. Therefore massive sanitation cuttings will commence as soon
as forest soils support heavy equipment. Clean-up operations are not easy and safety of
forest workers is a prime consideration due to the danger of broken and leaning trees and
spring poles, i.e. trapped trees which whip upwards when released.
The 8.4 million m3 which were felled in
Switzerland by the storms in 2 days are equivalent to 2 years’ of normal harvest. The
forest products markets have barely reached an equilibrium between supply and demand. Now
the surplus roundwood on an already fragile market could destabilize Europe’s timber
markets.
The ramifications of the 1990 storms
lasted 2 to 3 years. In 1991 and 1992 following the last storms, Germany stocked logs in
forests to reduce the immediate effects of an oversupply. Nevertheless prices of roundwood
plummeted and forest managers faced difficulties in paying for their management
operations. Governments will be called upon to assist in financing the resulting forest
operations.
Wood from wind-felled trees can be of
lower quality and subject to lower value uses. Rather than sound structural or furniture
wood, some of the windthrown timber will be of value for agglomerated particle board and
fibreboard, pulpwood or for energy production. The surplus of available virgin fibre could
have a negative effect on the recycled fibre market.
Meanwhile the public which depends on
forests for recreation will be faced with a changed landscape. Immediately access roads to
ski stations and crosscountry ski trails and alpine ski slopes were blocked. In the spring
and summer hikers, mountain bike riders and others who seek recreational opportunities in
European forests will be faced with obstacles and sometimes dangers from leaning and dying
trees. Many of the public will already be shocked at the damage to their urban trees and
forests and will be disappointed to find the countryside has been similarly affected.
"While it is too early to assess the
extent of the damage to Europe’s forests by the storms at Christmastime, the
precedent from the 1990 storms indicates that years will be necessary to bring forests and
markets back to a stable situation. However the destruction of century old forests will
take an equal time to return to their former state," concludes Edward Pepke.
For further information please
contact:
Information Unit
United Nations Economic Commission
for Europe (UN/ECE)
Palais des Nations, Room 356
CH - 1211 Geneva 10, Switzerland
Tel: +41 (22) 917 44 44
Fax: +41 (22) 917 05 05
E-mail: [email protected]
Website: http://www.unece.org