LES STEPPES ALGÉRIENNES: CAUSES DE DÉSÉQUILIBRE

Abstract

The Algerian steppes, located between isohyets 100 to 400 mm, cover more than 20 million hectares of a low vegetation and rabougrie, subjected to a very accentuated human exploitation. The vocation of the steppes is mainly the extensive breeding of sheep, supplemented by a random cultivation of cereals. Nowadays, the major report is that of a reduction in the surface of these steppes due to a sometimes extreme degradation. The whole is worsened by more or less severe and prolonged periodic drynesses. The permanent population growth and the desire of the improvement of the family income, associated with climatic precariousness, were at the origin of a deep transformation of the natural environment into Algerian steppe. This transformation is observed by the genesis of a certain number of phenomena, indicators of the degradation of the medium. Among more striking, one quotes primarily the deterioration of the quality of the courses with the fall of their productivity, the salinisation and turning into a desert of the grounds and finally, the genetic erosion of the resources and the fall of the biodiversity. With an aim of contributing to a better knowledge of the steppe zones, for a greater awakening of the complexity of rural development and actual position of degradation which knew these fragile areas, he was considered to be at the same time convenient and useful to carry out a development on the deep changes, accelerated during the passed decade, in particular the natural and anthropic causes of imbalance of these ecosystems.