Restoration techniques for degraded steppe courses: diachronic study in the Laghouat region (southern Algeria)

Abstract

Abstract Desertification of Steppe courses has become a major issue for Algeria because of huge loss of areas that have reached an irreversible stage of degradation. Therefore, soil and plant characteristics has been changed over the years causing the loss of ecosystem functions. In this context, the managers of Algerian state have acted to remedy the consequences of these ecological troubles, due to inappropriate human practices and accentuated by the harshness of the climate. In this diachronic study in the Laghouat region, 540 floristic samples and 180 soil samples were carried out to test some techniques for restoring degraded courses. It is about a combination of the grazing exclosure and some practical developments of soil (tillage) that are subdivided into mechanical methods (decompacting) and biological ones (adding: manure and mulch; watering; sowing of steppe species). The results have shown that these practices have several effects on floristic and soil parameters in short period (2 years). In fact, by these practices, a stimulation of plant species development has been observed. This has been detected by the increase in diversity index, plant cover and litter as well as the soil organic matter rate for all plots. On the other hand, the decrease in the bare ground surface. This increase is much greater in plots where decompacting with manure in first order and decompacting with sowing techniques have been applied. The technique of decompacting with mulching had a particular effect in the amount of litter with the technique of decompacting with sowing. The decompacting with watering has influenced phosphorus by promoting its availability. Decompacting all alone, which was the least effective, has increased the rate of coarse elements. According to these results, the soil-vegetation balance has been reinstalled by improving soil fertility and structure.