نوع مقاله : مقاله پژوهشی
1 استادیار گروه جنگلداری، واحد خلخال، دانشگاه آزاد اسلامی، خلخال
2 دانشیار گروه جنگلداری، دانشکدۀ منابع طبیعی، دانشگاه گیلان، صومعهسرا
3 استاد گروه جنگلداری، دانشکدۀ منابع طبیعی، دانشگاه گیلان، صومعهسرا
عنوان مقاله [English]
Single tree selection method needs to an accurate estimation of logging damage to residual stand for ecological and sustainable forest management. In this research accuracy and required time for estimation of frequency of damaged trees due to logging operation were assessed through plot and line samplings in a harvest unit of 30 ha area in Asalem Nav forest, northern Iran. In both samplings with same sampling intensity (10% of total area in plot sampling and equal total line lengths in line sampling) five samples size (plot and line sample numbers) were applied with different grid dimensions of systematic sampling method. The results showed that the sample size had significant effect (P < 0.001) on estimated damage in both samplings. A number of 30 plots of each 0.1 ha area in plot sampling and 50 line samples of each 60 m in length had lowest different (P > 0.618) with actual damage (100% inventory). Adequate grid dimensions were determined 100 m × 100 m with plot areas of each 0.1 ha for plot sampling and 77.5 m × 77.5 m with sample line lengths of each 60 m for line sampling. Required time for line samplings were about 90% lower than plot samplings. These results indicate the line sampling can be used for accurate and rapid estimation of frequency of damaged trees due to selection cutting and ground skidding.