Structure of natural Juniperus excelsa stands in Northwest of Iran

Abstract

Tavankar F. 2015.Structure of natural Juniperus excelsa stands in Northwest of Iran. Biodiversitas 16: 161-167. Juniperus
excelsa M. Bieb. stands are important forest ecosystems in mountain areas of Iran. In this research the structure of J. excelsa stands was
studied at altitudes of 1,400 to 1,900 m in northwest of Iran. The results showed that the mean densities of trees and seedling (trees with
height up to 1.3 m) were 99.8 ± 32.0 and 70.5 ± 18.3 stem ha-1, respectively. The juniper trees comprise 52.8% of the total tree density,
while the juniper seedlings comprise 19.3% of total seedling density. The mean of basal area in this stand was 3.12 ± 0.3 m2 ha-1 and the
mean of canopy cover was 42.7 ± 17.9 percent. The mean of trees height was obtained 2.75 ± 1.1 m. The total of 28 woody species
belonging to 14 families was recorded from the study area. The juniper trees had the maximum value of species importance value
(SIV=87.3). Amygdalus lyciodes and Pistacia atlantica were two tree species that have high SIV values, 34.1 and 27.0, respectively.The
distribution of trees density in different tree diameters resemble to a reverse J-shaped indicating uneven-aged structure. The results
indicated juniper seedlings were increased by increasing stand crown cover (P< 0.01). Moreover extreme environmental conditions,
grazing and timber harvesting for firewood are two important socioeconomic problems in these forests. These valuable stands needs to
urgently conservation strategies.