Characterizing the fixation of dunes in the region of Djelfa in Algeria

Abstract

Many experiments have shown that the improvement of plant cover is possible through some operations of human intervention. In our study area, after the introduction of anti-erosion fences, spontaneous vegetation has installed inside the grid, over the years, plant diversity has improved with 74 species in 2009 (22 families and 61 genus), demonstrating a significant reduction of troubles in the middle caused especially by the erosive action of winds and other microclimate factors.
Indeed, in non-fixed dunes (mechanical and biological fixation) vegetation is particularly present in the lower slopes of the dunes shelter where humidity is relatively high and the soil fertility. But in fixed environments, vegetation climbs to the tops of dunes serving to improve both the Microclimate by creating a gentle atmosphere under the effect of shade and transpiration, and the Floor by increasing its humidity of and improving its fertility through the provision of litter.
In all the fixed dunes and under the roots of planted species; a surface layer of soil ,reduced sometimes in a few centimeters is formed by fine particles of clays, silts, acting as a shield which reduces evaporation and therefore allows a relatively large water retention preserved for a long period of year. This layer is called "Self-mulching" is a colloidal material which sticks the sand after a biological dune fixation.