Study of tree quantitative and qualitative characteristics and soil fertility in pure and ‎mixed stands of beech and hornbeam

This research investigated some physical and chemical characteristics of soil as well as quantitative and qualitative characteristics of trees in three stands of pure beech, pure hornbeam and beech-hornbeam mixture. In each stand, 25 plots of 400 m2 were selected by systematic-random method. In each plot, quantitative and qualitative characteristics were recorded. Also, litter and soil samples (up to 10 cm depth) were collected from each stand. According to the results, maximum DBH (54.47 cm), total height (22.31 m), basal area per hectare (82.03 m2) and volume per hectare (991.43 m3) were observed in pure beech while having the lowest number per hectare (314 tree per hectare). The highest C and C/N ratio of litter in pure beech were 33.16% and 13.52, respectively. Also, the highest quantity of N in litter was determined in two species of pure hornbeam (3.22%) and mixed beech-hornbeam (3.06%). In terms of soil characteristics, pure hornbeam stand showed the highest amounts of soil reaction (7.09), N (0.33%) and soil N sequestration (5.49 tons per hectare) compared to the other stands. However, the highest amounts of C (2.63%), C/N ratio (10.27) and soil C sequestration (77.16 t / ha) were observed in pure beech. The results showed that pure beech stand in terms of quantitative and qualitative characteristics and pure hornbeam stand in terms of soil fertility are in a more favorable condition.