Risultati di prove di diradamento in rimboschimenti di pino laricio

Results of thinning trials for artificial stands of calabrian pine. The results of thinning trials carried out in plantations (aged 45) of Pinus nigra laricio Calabrica, at an intermediate stand development between the adolescent and the high forest, are here reported 10 years later the second thinning and after the third one. Within system of selective thinnings related to the differed number (800, 600 and 400) and to social position of selected trees in the main crops, the following theses are being compared: light thinning, intermediate thinning, heavy thinning and control. The second thinning effected positively the standing crop as compared with control plot: reducing mortality; increasing the annual diameter increments; differentiating the trees distribution for higher diameter classes; favouring the physical stability, the increments of basal area and stem volume, the renaturalization with autochthonous heavy seed broadleaves (chestnut, beech, turkey oak). Following the third thinning trees, the selected trees belong to the large-sized and high commercial value categories.