Increment borer

An increment borer is a special drill, which is mainly used in forestry and was developed in the 19th century by the forest scientists and economists Max Preßler.

Description

The hollow drill ( drill bit displacement ) is rotated with a T -shaped handle by hand into logs to extract core samples (usually 5 mm in diameter). In this way, the growth of wood, so followed the annual growth of the tree and the age of the tree can be determined. In addition, statements about the health of the tree ( rot) can be taken as well as the wood strength (breaking strength and bending strength of the drill core ) and simple sensory properties (odor ) are checked with a Fractometer. The drill hole is sealed with resin.

Utilization and Effects

The use of growth drills in forestry is controversial. Per hole produces a hole with an average of about 10 mm diameter. Through this channel, bacteria and fungi can penetrate into the trunk. In addition, the wood tissue is injured by the drill, vessels are pinched or cut. This triggered wound reactions can damage the wood over a large area. Around the borehole, it may cause discoloration. Another disadvantage of the increment borer is that irregular wood damage are poorly recognized, if not more holes are made. Because of these effects on tree growth in the use of drills is gradually decreasing, today they are used mainly for obviously diseased trees, about the identification of the pathogen used.