Austrian Federal Office and Research Centre for Forests (BFW)- Index Austrian Federal Office and Research Centre for Forests (BFW) | Forest Protection | Entomology
Damages by storms and danger of bark beetle disasters
Krehan H., Tomiczek Ch. German
ONLINE publications: Krehan | Tomiczek List of Publications: Krehan | Tomiczek

 
Damages by storm, Styria



 
Large windthrow, Styria




 Borkenkäfergefahr 
Danger of bark beetles
in windthrow-areas
PDF, 985k Byte  		Between October 2002 and January 2003 wind peaks of more than 150 km/h caused wind throw and wind break in large parts of Austria, though at different levels. According to preliminary surveys of the Provincial Forest Directions (Table) dead wood amounts to around 5 Mio m³ in total, and although clearly exceeding the long term average, it makes only 50 % of the damage from the 1990 storm disaster.

Services of the BFW

The BFW supports forest owners struck by the wind throw disaster in terms of providing information via the internet (Wind Throw Service of the BFW). Salvage-logging comes first as an emergency measure. Therefore, it is important to contact first harvester enterprises . The The Forest Training Centre of Ort/Gmunden offers special training courses for salvage logging.

Upcoming bark beetle disaster?

Normally, a larger amount of dead wood through storm and snow means also an increase in the bark beetle damaged wood but this can be proved only two to four years later. This time it can be observed that the initial population of Ips typographus and Pityogenes chalcographus exceeds by far the "iron stock" which favours a rapid mass outbreak during favourable weather conditions.

What has to be done?

  • " During the first winter the wind throw areas are ideal breeding sites for bark beetles. They can also be used as trap stems. It is very important to bark off or even remove the infested trunks at least before the first beetles start to fly which is normally mid of June. In single cases the application of trunk protectors (insecticides against bark beetles) helps to avoid a worst-case scenario.
  • " Clear up first the stands located at lower elevations exposed to south, followed by east or west exposed locations later on.
  • " Stands which showed already bark beetle trees before the storm damage are also considered to be particularly endangered and should therefore more quickly be harvested.
  • " The trees of the remaining stand which are not thrown show root snaps after the storm event; also these trees are rather suited for trapping beetles? Ongoing inspection by trained staff is necessary.
  • " Slashings (tree tops, twigs and branches) are ideal brood material for Pityogenes chalcographus. Laying out heaps of twigs may reduce the danger. If an infestion with Pityogenes chalcographus is detected, further development of the pest may be hindered by the application of insecticides or burning of the slashings.
  • " Any omission of the present time will take it's toll one day.

    • Service Hotline "Bark Beetle Control":

    01-87838 - 1128 or 1145 or 1133

    Storm damage research abroad

    Switzerland
    During the last decade Switzerland was struck by two European-wide storm disasters: the winter storms "Vivian" in February 1990 and "Lothar" in December 1999. "Vivian" induced intensive research activity at WSL on the development of damaged stands so that 9 years later the generated data could be used for the next storm "Lothar". Some of the published research results may help Austrian forest owners to cope with this problem.
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    30.4.2003 Further information: Hannes Krehan Index BFW | Forest Protection | Search