Comparative investigation of Oriental Plane and White Poplar plantations near Zayanderud dam, Isfahan

This research was conducted to measure quantitative and qualitative characteristics of trees and to determine amount of annual increment for poplar and plane, specially their volume and wood production beside Zayanderud dam. Two plantation areas with 3×3 meters spacing were selected for sampling after field survey. A 30-years-old poplar and a 30-years-old plane stand. In each stand, five tree lines were selected randomly for measurement. In each line all trees were measured for total and trunk height, diameter at breast height and crown diameter. Tree annual increment was computed for various traits knowing stand age. Independent samples t-test was applied in order to determine differences and compare the means. Results showed that poplar stand had more DBH (33.8 cm), basal area (1184.1 cm2), volume (2.19 m3) and total height (38.25 m) than plane stand. Also the most height growth (1.27 m.year-1), diameter growth (1.12 cm.year-1) and volume growth (0.073 m3.year-1) accrued in poplar stand. Crown area in poplar trees (9.5 m2) was more but had no significant difference with plane trees whereas trunk height of plane trees (15.7 m) was significantly more than poplar trees. The finding suggested that poplar has more growth and wood production than plane and is more suitable for current conditions. As stability index was not suitable for studied plantations (more than 100) it seems that silvicultural operations specially thinning are inevitable and are recommended to increase wind resistance.