Studying the ecological requirements and quantitative properties of Crataegus azarolus L. natural stands in west Azerbaijan province

Crataegus as a woody multipurpose species based on fruit production is very important for local residents in the Northern Zagros forests located at the south of West Azerbaijan province. This study aimed at determining the quantitative characteristics, soil and physiographic properties in the Crataegus spp. stands. In current study, eight Crataegus habitats were selected and 3-5 0.1 ha circular sample plots, totally 33 sample plots, were established in each habitat by random systematic method. General characteristics of sampling plot and dendrological properties including diameter at breast height, origin of trees, large and small diameters of canopy were measured. Ten soil samples were taken within studied habitats. The results showed that pH, organic carbon content, total nitrogen and clay are the most effective soil factors on the distribution of Crataegus species. In addition, results imply that Crataegus azarolus and a few pyrus appear with increasing the soil pH and clay and southfacing slopes. Other Crataegus species associated with such species as Malus, Quercus, Salix, Fraxinus, and ulmus are observed with improving the soil fertility, increasing the organic carbon and total nitrogen and north-facing slopes. The maximum and minimum diameter at breast height of Crataegus species individuals were observed in Galatian site (17.42 cm) and in Darre Shohada (6.61 cm), respectively and also the maximum and minimum of average canopy area were observed in Mirabad 2 (24.3 m2 ) and Darre Shohada site (4.49 m2 ), respectively. It is recommended that Crataegus azarolus would be planted in the western and southern aspects and low soil fertility and other species of this genus would be planted in northern aspects with higher soil fertility.