Öz The vast part of the Bolu Mountains is under the influences of Oceanic climâte. The study area is situated in the westem secteur of the Euxinian region. On the supramediterranean zone of the area the decidious formations of Quercus hartuis- sifina X Q.petraea and Carpinus betulus occur while those of Pinus nigra subsp. pallasiana and Pinus brutia are very local.