Some structural features of forest types in Hyrcanian forest (A case study: Palang-Darreh forest, Savadkoh)

It is very important in forest planning to recognize forest types and their classification in similar or different groups, their distribution pattern, mixture, frequency, dominance and abundance at the various area. Therefore, the purpose of current research is to identify, classify and introduce forest types, also determine some structural parameters and, other statistical components on these types. For this study, randomized-systematic sampling was used. After the statistical calculations, eighty sample plots were deployed. To understand the natural regeneration condition, five sub-plots were measured in each plot in four directions and the center of the plot. The seedlings height includes <30, 30-130 and, >130 cm was measured with decimeter precision. In this study, forest types have been classified based on factors such as physiognomy, dominance, species composition, physiographic conditions, and forest type extension. The results showed that 17 tree species belonging to 17 genera and 13 plant families were identified. The mean volume per hectare was equal to 317 silv, which beech, maple and hornbeam species have the highest proportion. The volume per hectare of beech stands includes 440.8 silv. Totally, the number of trees per hectare comprises 485 trees. More than 52% of the total regeneration belongs >130 cm height, 17.62% belongs 30-130 cm height and 30% belongs <30 cm height. Among the species, Diospyros lotus, Box-plants, Ironwood, maple, and beech constitute the majority of regeneration, respectively.