The bark beetle complicates the lives of foresters all over the country, and in recent years its ravaging effect has intensified. Millions of cubic meters of wood fall victim to it every year, and expert prognoses for the future are not exactly favourable. That’s why experts from the Drones Section of the SIT Information Technology Administration of the City of Pilsen have become involved in the fight against bark beetles. Unmanned aircraft can help foresters in the early detection of this persistent pest.
Thanks to drones, experts are able to create a so-called orthophotomap of a large area covering tens of hectares of forest. With the help of a drone, they take photographs which help to spot dry tops of trees indicating bark beetle circles, which are a typical sign that a forest has been infested by the bark beetle. This gives foresters an opportunity to see a large part of the forest in a short time, allowing them to save time and gain a valuable advantage over the bark beetle. From the photos, they can pick out suspicious trees in the area and then inspect them visually, as it is easy to determine the exact GPS coordinates of any place in the image. This method can be used in the detection of the double-spined bark beetle and the small spruce bark beetle.
For perhaps the most significant pest, the European spruce bark beetle, the colleagues have chosen a different method. This is due to the fact that after the forest is infested by the European spruce bark beetle, the tree does not dry out immediately from the top, but first loses its bark. This process is not visible from the classic photographs taken by drones. When the treetops dry out, trees are already in an advanced state of infestation and it is probable that the bark beetle has already spread to surrounding areas. For this reason, it is necessary to scan a selected area using a multispectral camera carried by a WingtraOne drone. This camera captures vegetation in spectra that are invisible to the human eye. The aim is to verify the hypothesis that we can detect tree infestation that is invisible to the naked eye with the help of data from the multispectral camera. In this way, affected trees could be identified at a time when this species of bark beetle has not yet left them, thus preventing their further spread. Moreover, the drone experts are developing their own application for data analysis to evaluate the data efficiently.
