Study on floristic composition, chorology and ecological structure of Gisoum forest reserve, Talesh, Iran

This study was carried out on vegetation of Gisoum forest reserve with 171 hectares Area located in 14 km to Resvanshar city, Guilan province, to examine the structure and composition of the forest vegetation. The first topographic map of the area with the scale of 1:10000 was prepared and the study area was delimited. Transect- quadrate method of sampling was used to record the floristic and phytosociological data necessary for the analysis in about 44 uadrates of 400 m2. Some vegetation parameters viz. density and diameter at breast height (DBH) for trees (over story vegetation) as well as cover-abundance for under story vegetation were recorded, respectively. Life form spectrum of Raunkiaer, the dominant vegetation type of the area based on importance value and vegetation structure based on frequency classes, also their chorology caring a central importance in vegetation description and analysis were determined. The study of floristic list showed that 76 species belonged to 66 genera and 45 families that Asteraceae and Rosaceae with 5 species were the most families that have the highest number of species. Investigation on geographical distribution of plants species indicated that 44 % belonged to Europe – Siberian zone. plant life forms by Raunkiaer method showed that phanerophytes with 35.5 % and hemicryptophytes with 27.6 % were the most frequent life forms. Dominant vegetation type based on importance value index was Buxus-Parrotia. Also the evaluating of vegetation structure based on frequency class revealed that abundance-distribution was irregular in under story and regular in upper story vegetation.