Phytoecology of the Atlas Pistachio (Pistacia Atlantica sub sp. Atlantica) in the Area of Laghouat (Algeria)

The present work aims to study the floristic and ecological formations of Pistacia atlantica in the dayas of the wilaya of Laghouat phytoecological approach. One of the essential characteristics of the vegetation of this area is great plant diversity. The pistachio tree of the Atlas (Pistacia atlantica) is a very hardy xerophilous tree with great amplitude vis-à-vis the climatic factors not affected by the long periods of drought. The floristic inventory carried out has allowed us to identify 45 taxa, divided into 24 families and 40 genera. Systematically, the Asteraceae and Poaceae are the best represented, 20% of the floristic richness. The biological analysis shows the importance and predominance of therophytes on the other forms, this predominance is characteristic of the vegetation of arid regions which are adapted to the Saharan and steppe environment. From the biogeographic analysis, it emerges the predominance of the Mediterranean element. The numerical analysis, by the use of the analysis of the relaxed correspondences (DCA) and the ascending hierarchical classification (CHA), allowed us to individualize two floristic sets as well as the ecological factors which govern their distribution.