Structure of Oak (Quercus macranthera) Forest Stands in the Golestan Province

Study of forest structure is one of the basic requirements to achieve the objectives of close to nature silvicultural treatments. The study of forest structure in northern parts of the country is a new and important approach, besides more attention should be paid on the necessity of the structure of local oak forests, due to the harsh environment and its sensitivity. For the purpose of this research, three representative sites were carefully selected after a concise field and map recognition at the Golestan province mountainous forests (Derazno, Shirinabad, and Loveh). At each site, 4 sample plots with one hectare area (100×100 m) were established according to a random systematic design. In addition, at four parts of each sample plot a subplot (15×15 m) were determined for regeneration study. At each main plot, a 20×50 m plot was also established for further study of vertical and horizontal profile. The statistical packages used for all analyses were SPSS-and SVS. Results showed that, Quercus macranthera is the dominant species at site one (Derazno, Kordkoy) and site two (Shirinabad-Aliabad). Maximum crown canopy was 61% of the total (76.5% and 23.5% for Quercus macranthera and other species, respectively). At Derazno site, a more favorable condition compared to the other sites were observed. Stand mean diameter and height were 80 cm and 14.5 m, respectively. Stands diameter distributions showed an uneven-aged shape. The main issue was the fact that the regeneration density was not enough; except for site one at Derazno. The comparison of mean diameter, height, tree standing volume and basal area by using of ANOVA, and F test, suggest a significant difference, at 1% confidebce level for various sites.