Effect of index species of Artemisia sieberi on associated plant of Stipa barbata (Case study: Anjedan rangeland, Arak)

The aim of this research was to investigate the effect of index specie of Artemisia sieberi on associate plant of Stipa barbata from different aspects. The study was carried out in Anjedan rangeland located in Markazi province. After delimitation of study area، to consider their density and correlation، totally 30 A. sieberi individuals were determined randomly and individuals of index and associated plants (A. Sieberi and St. barbata) for each 30 points in 50 cm distance were counted. Presence of index and associated plants were recorded along four transects of 50m length based on randomized – systematic method. At starting and end points of each transect، soil samples were taken from adjacent control area to compare soil properties in control area and index species habitat soils to find out the effects of index species on soil properties. Soil samples were analyzed in laboratory to determine texture، pH، Ec، OM، lime، Na، K، P and N. Data were analyzed and comparisons were made using SPSS software. Results showed that density changes of A. sieberi and S. barbata were similar along the transects. Correlation studies using Chi - square indicated that there was a huge positive correlation between A. sieberi and S. barbata. Soil characteristics comparison in two areas revealed that only lime content was significantly different which was higher in A. sieberi habitat soil. Totally، it was found that A. sieberi has positive effect on presence of S. barbata.