Document Type : Research article
Authors
1
Ph.D. student of Forestry, Forestry Department, Faculty of Natural Resources, Urmia University, Urmia, Iran
2
Corresponding author, Associate Prof., Forestry Department, Faculty of Natural Resources, Urmia University, Urmia, Iran
3
Prof., Forestry Department, Faculty of Natural Resources, Urmia University, Urmia, Iran
4
Assistant Prof., Forestry Department, Faculty of Natural Resources, Urmia University, Urmia, Iran
Abstract
Background and objectives: Greek juniper (Juniperus excelsa M.Beib.), one of the few coniferous species in Iran, is distributed across many mountainous regions and provides essential ecosystem services, including carbon sequestration, soil erosion control, and aesthetic value. However, inadequate appreciation and overexploitation in recent decades have led to the degradation or loss of many valuable Greek juniper sites. This study aims to evaluate the quantitative characteristics of Greek juniper stands in the Doostak Natural Reserve, West Azerbaijan province (northwestern Iran).
Methodology: The Doostak Natural Reserve, located 35 km south of Urmia city, spans approximately 200 hectares. The stand mainly occupies northern and western slopes at elevations between 1575 and 2157 m above sea level, with an average slope of 50%. The Prodan multiple-tree sampling method was used to assess density and distribution, with 54 sample plots selected across different elevation, slope, and aspect classes. Within each plot, quantitative tree variables such as diameter at breast height (DBH), height, crown perpendicular diameters, and regeneration were measured. Regeneration was assessed in 100 m² subplots at plot centers. Data normality was tested using the Kolmogorov-Smirnov test, and variable differences were analyzed via ANOVA, Duncan, and independent t-tests.
Results: Greek juniper accounted for more than 85% of trees and shrubs in the study area. Associated species included Prunus spp., Pistacia atlantica Desf., Acer monspessulanum L., Lonicera spp., and Cotoneaster spp. The maximum recorded height, DBH, and crown area of Greek juniper trees were 8.6 m, 53 cm, and 52 m², respectively. Elevation significantly affected juniper DBH, and mean tree height varied significantly with geographic aspect. More than 66% of junipers originated via coppicing, which was more frequent at lower elevations due to repeated local cutting combined with junipers' high coppicing ability. North-facing slopes, with greater moisture and better-developed soils, provided superior conditions for juniper establishment and growth. The number of standard trees increased with elevation and slope steepness.
Conclusion: Comparison with other studies suggests that physiographic factors influence juniper quantitative traits differently across regions, likely due to interactions with human activity, climate, and geographic position.
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