NATURAL REGENERATION OF Juniperus excelsa IN RELATION TO STAND CHARACTERISTICS IN NORTHWEST OF IRAN

The Juniper excelsa stands are distributed in large areas of Iran and have ecological importance. Restricted natural regeneration of J. excelsa is one of the problems in these stands. In this research natural regeneration of J. excelsa in relation to stand characteristics (tree density, canopy cover and tree species diversity) were investigated in the northwest of Iran. A total of 28 woody species belonging to 14 families were recorded from the study area. The total density of trees was 74.8 stem ha-1. The density of J. excelsa was 32.7 stem ha-1, which comprise 43.7% of the total tree density. The J. excelsa had the highest value of basal area (0.37 m2ha-1, 33%) and species importance value (85.1). The total regeneration density was 60.5 stem ha-1, and the J. excelsa had 11.3 stem ha-1 (18.7%). Species diversity of stand trees (Shannon – Wiener index) were divided into three classes: low (H' < 0.5), medium (0.5 < H' < 1) and high (H' > 1). The means of juniper regeneration densities in the low, medium and high tree species diversity classes were obtained 3.7, 8.1 and 20.4 stem ha-1, respectively. The results indicated that regeneration density of J. excelsa was increased by increasing stand trees density, stand canopy cover and stand trees species diversity (P = 0.01). The forest management objectives should be to increase density and species diversity of trees in these stands.