Abstract
The resistance force was measured as hung-up trees were passed through the crowns of remaining trees in a Chamaecyparis obtusa stand. The average resistance force was 1.0 kN. A large force was needed to remove manually a tree hung up between two standing trees in an overcrowded thinning stand. The size of a hung-up tree did not have an effect on the resistance force, while leaning angle at which the tree was hung-up influenced the resistance force strongly. The distance between the remaining trees affected the resistance force, which increased exponentially as the distance between the remaining trees decreased.
