DESCRIPTION OF THE SPATIAL DISTRIBUTION OF STEPPE VEGETATION ON THE AEOLIAN SAND DEPOSITS

Ploughing and overgrazing increase the risk of land degradation in arid zones, while silting and wind erosion are the consequences, some plants disappear and others persist and adapt. Fixing moving sediments in risk areas. To this aim, we focused on identifying steppe plants that can grow in a silted environment and to determine their distribution rate on the sand dunes. We carried out these vegetation inventories in the Mokrane region (Laghouat) in March 2019, using the floristic transect method. The height of Aeolian deposits was measured under all points every 20 cm along the tape of the floristic transect in the study area after slope correction by the topographic levelling method. We have identified 11 plant species. The heights of the fixed Aeolian deposits by the plants ranged from 28 cm to 63 cm, which is lower than those of the non-fixed deposits, ranged from 36 cm to 97 cm. For the three perennials (Aristida pungens, Retama raetam, Astragalus armatus), the elevations of the underlying Aeolian deposits were not statistically different; noting that Aristida pungens had the lowest values up to 29 cm. Aeolian deposits in the study area formed a microdunes that did not exceed 1 m. The height of the sediments accumulated under the canopy provided information on the role of perennial species in sand fixation and the order of plant establishment on the trapped sediments.

Automated summary

Ploughing and overgrazing in arid zones can lead to land degradation, with silting and wind erosion as consequences. Some plants disappear while others adapt. This study aimed to identify steppe plants that can grow in silted environments and determine their distribution on sand dunes. Vegetation inventories were conducted using the floristic transect method in the Mokrane region in March 2019. Results showed that certain perennial plants were able to fix moving sediments, resulting in lower heights of Aeolian deposits compared to non-fixed deposits. The study also revealed the role of perennial species in sand fixation and the order of plant establishment on trapped sediments.