The Norwegian forest research institute "Norske Skogforsk" has realized a project for registering the scope of forest damage by means of laser beams from aircraft. The experiment was carried out in connection with the extensive attacks by European saw flies in the province Hedmark last summer.
The principle of this method for charting forest damage is that a great deal of the laser beams can penetrate thin forest and are reflected from the ground. And inversely; in fresh, healthy and dense forests with a lot of needles and leaves most of the laser beams are reflected from the tree tops.
The conclusion of the project is that such laser scanning is very well adapted for measuring the so called leaf area index, which in turn can be exploited for charting and quantification of forest damage.
Because of the high costs of using aircraft commercial exploitation of this registration method can be competitive only in respect of big damages areas, i.e. more than 3 000 hectares.