[01] Mansooreh Aghasizade, Department of Forestry, Faculty of Natural Resources, University of Guilan, Rasht, Iran. [02] Kambiz Taheri Abkenar, Department of Forestry, Faculty of Natural Resources, University of Guilan, Rasht, Iran. [03] Seyed Mahmood Monemian, Department of Forestry, Faculty of Forestry and Forest Ecology, University of Göttingen, Göttingen, Germany. [04] Seyede Maryam Taherzadeh Mousavian, Department of Forestry, Faculty of Natural Resources, University of Guilan, Rasht, Iran.

Natural resurgence is one of the most priorities of the forest management. In this study, in order to investigate regeneration success and determine the best gap area, the quantitative characteristics of the regeneration groups were evaluated at different gap area classes. Because of the dense natural forests, Quercus castaneifolia in northern Khorasan province of Iran, determination of the best gap area for the better resurgence was aimed 30 gaps were selected in three different areas. Some selected Parameters such as steep, direction, height and shape of the gap and percent of the canopy cover and the disturbing vegetation were determined. Quantitative characteristics such as light, resurgence, diameter at breast height and collar diameter of oak seedling (Quercus castaneifolia) with height over 1.30 m were measured in the different size gaps. The shape of the gaps was mostly oval-like and the regeneration in the gaps of 5 up to 8 R was better rather than the others. Percent of forest canopy cover decreased while the surface of the gap increased. Moreover, the percent of the disturbing vegetation cover, diameter at breast height (DBH) and collar diameter (CD) significantly correlated with the increase of gap area. It is concluded that the gaps should not be made in the area with 8 R or more unless the disturbing grass cover be removed.

Iran, Gap area, Natural Forest, North Khorasan, Quercus castaneifolia, Regeneration

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