Abstract
The wind-shaped trees were observed in order to make clear the distribution of bores on the Adriatic coast from Istria Peninsula to Dubrovnik and on the five islands, Krk, Cres, Lošinj, Rab and Pag. The observation was carried out at 380 points. The main species of trees observed were Ostrya, Fraxinus, Quercus in the northern part and Pinus in the south. The results can be summarized as follows : (1) The strongest bora region is located near Senj. The ENE wind flows out from the Vratnik pass. It turns gradually as NE flow on the sea and reaches to Cres and Lošinj islands as NE-NNE flows. (2) The strongest bora reaches as far as 50-60 km from the coast. On the north and south of this region, the bora is strong as far as 20 km from the coast. (3) The strong NE wind appears only in restricted areas south of Zadar. On the contrary, E-SE winds, Jugo, become to prevail. (4) On the slopes of the Dinar Alps facing the Adriatic Sea, the NE winds are strong up to 800 m above sea level and become weak suddenly at a height of 1, 000 m. At the pass topography with a height of 700-800 m, the wind is very strong locally. (5) On the islands, a contrast between the windward slopes and the leeward slopes is extraordinally sharp. At the col situation, the wind is very strong. (6) There is a high correlation between the mean wind velocity (m/s), Ww, in January, and the grade, Gw, of the wind-shaped trees. It is expressed by a linear equation by
Ww=3.231+1.64 Gw
