Impact of Over–Grazing on Plant Diversity and Phyto–Geographical of the Steppe Ecosystems of Southern Oran (Western Algeria)

HASNAOUI Okkacha; BORSALI Amine Habib et; BENARADJ Abdelkrim

Volume : IV, Issue : X, October - 2014

Impact of Over–Grazing on Plant Diversity and Phyto–Geographical of the Steppe Ecosystems of Southern Oran (Western Algeria)

Hasnaoui Okkacha, Borsali Amine Habib Et, Benaradj Abdelkrim

Abstract :

Ecosystems of southern Oran (Western Algeria) are currently exposed to climatic and anthropogenic impact unprecedented. This study proposes an inventory of plant species in three steppe formations at Stipa tenacissima impacted differently. The method used is based on the abundance dominance. The taxa identified are classified on systematic and biogeographical. The floristic inventory indicates a regressive dynamic training Stipa moving from one site to another. 39 plant species have been recorded in the site Stipa in good condition, against 26 for the site moderately degraded and 16 species only for the degraded site. Endemic species (Muricaria prostata; Astragalus armatus; Erucastrum leucanthum); Saharan taxa (Bassia muricata, Centaurea pungens) and Saharo&amp;ndash;Sindiens (Senecio flavus Erucaria uncata) have disappeared from the degraded site. We are witnessing a change in the steppe physiognomy in which toxic and / or thorny species are growing (Paronychia argentea; Peganum harmala; Eruca vesicaria) at the expense of palatable species.