Comparison of Alnus and Acer Growth in Pure and Mixed Plantation stands (Case Study: Neka District -Forest of Mazandaran Province)

This study was investigated the growth of plantation stands of maple (pure and mixed) and alder (pure and mixed) in district 1, section 2 Zalemroud – Neka, Mazandaran, at different levels (2.1, 2, 1.58 and 1.48 ha) at age 19 with planting distance of 2 × 2 m. The study area has been measured using the full inventory method. Diameter of all trees and height (total, average, crown and trunk) of 10 trees in the diameter classes (15, 20, 25, 30 and 35 cm) and a total of 50 trees per stand were measured as control trees. Also, 65 trees in four mentioned stands in diameter class of 5 cm of diameter classes (15, 20, 25, 30 and 35 cm) were selected randomly which were 4-5 trees in each stand and at height of 30 and 1.30 cm from ground wooden disks with thick of 5-10 cm were cut for a accurate growth study (total, current and average) and various growth factors were calculated. The results showed that the basal area of stands were 29.14, 18.5, 21.15 and 24.03 m 2 /ha, respectively and the mean volume of stands were 218.31, 145.9, 209.57 and 198.05 m 3 /ha, respectively. Maximum diameter growth of maple (pure and mixed) were 1.31 and 1.45 cm for ages 7 and 3, respectively and for alder (pure and mixed) were 1.32 and 1.55 cm for ages 3a and 4, respectively