Relationship of Growth components of Bladder Senna (Colutea persica Boiss.) with soil and physiographic factors in Kandiragh forest reserved of Khalkhal- Ardabil province

Colutea persica is one of important and valuable species in Kandiragh forest reserve of Khalkhal. This study aimed to determine the relationship between Growth properties of Bladder Senna with soil and physiographic factors in Kandiragh forest reserve. in three land forms (ridge, valley and slope) and in four aspects (north, south, east and west) from lower to higher distribution areas sample plots, each 500 m2, were selected. Overall, 32 sample plots were used for measuring Growth characteristics; soil characteristics were studied in 12 sample plots including soil texture (clay, silt and sand), pH, Ec, N%, OC% and Caco3%. The results showed that the distribution range of Bladder Senna varies from 1350 to 1980 m.a.s.l. In general, slopes and ridge forms with south and east-facing slopes are suitable sites for this species. The highest figures of Bladder Senna individuals including height (1.75m), crown diameter (1. 81 m) and regeneration (169.N/h) on valley form and the highest number of shoot (13/11) on slope form were measured. Soil of Bladder Senna habitats is deep to semi- shallow with pH (7.4 to 8.1), Ec (0.21 to 0.39 ds/m) and with soil texture of loam to loam- sand. The PCA analysis showed that the physical properties of soil (sand, clay and silt) and Ec have an important impact on the presence of this species. So that, the presence of Bladder Senna in the southern and eastern slopes has more correlation with silt percentage.