عنوان مقاله [English]
This research was performed to determine the facilitation effect of some species in a degraded rangeland on establishment and primary growth of two important forage spices: Agropyron desertorum (Fisch.) Schultes and Secale montanum Guss. Acantholimon festucaceum (Jaub & Spach) Boiss, Eryngium bungei Boiss, Noaea mucronata (Forsk.) Aschers. and Peganum harmala L. were studied as Secale montanum nurse plants and Acanthophyllum bracteatum Boiss., Astragalus arbusculinus Bornm. & Gauba, Ephorbia orientalis L. and Noaea mucronata (Forsk.) Aschers. were investigated as Agropyron desertorum nurse plants. Seed sowing of the two forage species was carried out in the middle of autumn in the understory of nurse plants and the space between the plants. The soil moisture was measured at two depths of 0-10 and 15-25 cm. After analysis of variance, mean comparisons were made by Duncan's method. According to the results, due to the facilitation effects of Acantholimon festucaceum, Eryngium bungei, Noaea mucronata, and Peganum harmala, the primary growth (height) of Secale montanum seedlings was calculated to be 3.4, 2.6, 3.9 and 2.2 times higher than the open space treatment, respectively. All species had similar positive effect on the primary growth (height) of Agropyron desertorum; however, Noaea mucronata, with the most positive effect, could increase the establishment rate to 62 %. Considering the importance of facilitation effect of deformed populations of Noaea mucronata in increasing the primary establishment of Agropyron desertorumandprimary growth of Secale montanum, the use of Noaea mucronata nurse role in autumn rangeland improvement is recommended to the natural resources offices.