Plant associations in Baharbon district of Kheyroud Forest and its relationship to land forms

The aim of this research was to study the plant associations in Baharbon district of Kheyroud Forest (north of Iran) and their relationship to physiographical factors. Determination of plant associations and sub associations were done, using Braun - Blanquet School. For this purpose, 51 releves consisting of 100 m2 area, were located at different sites. The phytosociological data was analyzed by the Factorial Correspondences (AFC) and Classification Ascendant Hierarchique (CAH) methods, using the Anaphyto software. Nine associations consisting of Querco macrantherae-Carpinetum orientalis, Fraxino excelsioris-Aceretum velutini, Parrotio persicae-Quercetum castaneifoliae, Parrotio persicae-Carpinetum betuli, Pterocaryo fraxinifoliae-Alnetum subcordatae, Aceri velutini - Fagetum orientalis, Carpino betuli-Fagetum orientalis, Rusco hyrcani-Fagetum orientalis and Fagetum orientalis were distinguished in this forest. Then relationships between the associations and the landform features were investigated, applying the DCA method and CANOCO 4.5 software. The results showed that although there were significant relationships between the associations and the altitude and the geographical aspects; but there was not significant relationship with the slope gradient.