Assessing the Implications of Planting Haloxylon aphyllum on the Vegetation and Soil Properties of Stabilized Sandy Desert (Samad Abad, Sarakhs)

Planting Haloxylon aphyllum under oil mulches has frequently been used for stabilizing mobile sands in Iran for during the last three decades. This study is carried out in stabilized sandy desert of Samad Abad-e-Sarakhs to evaluate the implications of planting Haloxylon aphyllum on the vegetation and soil attributes. Sampling was carried out random-systematically in the representative areas of the treatment and control plots. In each treatment and control area nine transects of 50 m were placed and data including the density and the canopy cover of the two dominant species of the field (viz. Astragalus squarrosus & Convolvulus hamadae) as well as the total canopy cover of the understory plants were recorded. In addition, in each area 220 plants of the two species were selected and examined for their total and living aerial foliage volumes. What’s more, four soil profiles were used in each area and sampling was made at the depths of 0-20 cm and 20-80 cm to be further analyzed for the organic matter content. Data analysis was performed using the independent t-test. Results indicated that planting Haloxylon aphyllum has reduced the total canopy cover beside the canopy cover and densities of the two dominant species. The implications also include the reduction of the total volume of Astragalus squarrosus, yet there was no such reduction for Convolvulus hamadae. As a result there was significantly reduction of organic matter content at the surface depth and accumulation of it in the deeper depth.