Effect of Crown Gap Size on Forest Natural Regeneration Establishment and Survival (Case Study: Parcel No 18, Forestry Plan Jamand Series)

Understory treatment and reaction are due to crown opening, which light condition to be change intensity after gap forming.
In this research parcel No 18 of forestry plan jamand series was selected. By dealt with a 100 percent survey and an entire field on all natural gaps in it, was surveyed about the effect of these gaps on forest natural regeneration. The trees in the margin of the gaps surveyed according to kinds of tree species. In this research gap size was studied in 4 classifications: 50-200, 200-400, 400-600 & 600-800 square meter and analysis was done on them.
Findig: According to the conclusion, averages of large and small diagonals of the gaps in its various types have significant difference at 5% level. With the increasing in the gap size diagonals of the gaps increases, too. The most of the seedling mortality were seen in the microplot which measured in the 4th class (6-8 are) and it has significant difference at 5% level. Most of the Carpinus betulus L. trees were seen in the margin of the gaps lesser than 2 are and with increasing the gap surface Carpinus betulus L. tree decreases. Regeneration establishment and its variety didn’t have significant difference at 5% level in the surveyed groups.
Generally in this research with increasing in the gap surface, light and temperature stress increases, too, and it causes seedling mortality.