Assessment of Quantitative and Qualitative Characteristics of Golestan Province Forests in an 11-Year Period (Iran)

The impacts caused by natural factors and human interventions during specific sampling periods have substantial influence on nature and the selected management method. the present research was carried out in golestan province forests, iran over an 11- year period and the obtained data was analyzed based on systematic random sampling method with fixed sample plots (0.1 ha). the data including species, dbh, height, qualitative degree in the first six-meter of the stem, percentage of canopy, and regeneration status in sample plots were measured and recorded for sampled trees. the results showed that the sample plots in golestan province forests increased from 1018 at the beginning of the studied period (1996) to 1114, at the end (2007). the inventory performed in 2007 showed that considering the percentage of canopy, the areal percentage of these forests increased in 0-30% and >80% canopy classes compared to those in 1996; however, there was a considerable reduction in the percentage of canopy in the given forests in 30-50% and 50-80% classes. comparing the productive and non-productive forests indicated that the area of protection and conservation forests increased in 2007 compared to that of the year 1996. the results also revealed that the number and volume per hectare of trees in golestan province forests were dramatically reduced to 53.6n.ha and 1104.9m^3ha^-1 respectively. this reduction was more remarkable for the main species of the studied forests including horn beam, chestnut-leaved oak, beech, and velvet maple. the highest reductions of number of tree species were observed in 20, 25, 30, 35, and 40cm diameter classes, while the variations of volume (vs. number) in diameter classes exhibited more fluctuations. comparing the status of dead wood in the studied forests revealed that the highest number of dead wood (58.5%) and volume/ha (66%) occurred in horn beam compared to other species. the research also indicated that the highest abundance of regeneration pertained to seedling and sapling vegetation stages.