EFFECT OF THINNING AND GRAZING ON TREE DEVELOPMENT AND THE VISUAL ASPECT OF AN OAK FOREST ON THE GOLAN HEIGHTS

An attempt to create an open woodland was made in Israel by opening la rge tracks of maquis thickets by hand, cutting out lower shrubs, and t hinning, coppicing, and pruning desirable trees. Three treatments were compared: moderate, heavy, and control with no thinning. The effects of the treatments on the visual transparency of the forest were measur ed by a transparency index defined as the maximum distance from which a vertical post 1.8 meters high could be fully observed. In general, t hinning caused a 38.0% increase in the diameter of all the trunks over a seven-year period for heavy thinning, compared with 26.4% and 12.8% in the moderate and control treatments, respectively. The difference between heavy and moderate thinning was not always significant. A comb ination of thinning and grazing successfully created an open woodland, without additional input of resources. The ''transparency index'' use d in this study can be used as a quantitative measurement index for ac cessibility and aesthetics.