Diversity and floristic analysis of Pistacia lentiscus L (Anacardiaceae) groups in Tiaret region (West Algeria)

This study aimed essentially at the knowledge and analysis of associated Pistacia lentiscus L groups in the Tiaret region. By an analytical and statistical approach of the floristic inventories made in this area, three stations (Saffalou, Plateau and Guertoufa) were selected during the optimal vegetation seasons March-June between 2015-2018. A total of 166 species was identified; these species grouped into 131 genera and 43 families highly dominated by Angiosperms (98.2%). The most represented families were Asteraceae, Poaceae, Fabaceae, Cistaceae, Lamiaceae and Brassicaceae with percentages (15.1%, 10.8%, 9%, 6%, 5.4% and 4.8%), respectively. The biological spectrum of the flora was dominated by Therophytes (51.2%), whereas Mediterranean species group was well presented (54, 8%) compared to the other groups. Ecological indexes calculation showed that, Shannon index revealed a high diversity (H = 4.6), Pielou Equitability (J = 0.9) indicated a regularity in species distribution whereas Simpson Index (1- D = 0.98) reflected a low diversity of stands. Meanwhile, the overall perturbation index (PI = 63%) reflected the openness of the environment. Moreover, Jaccard (S) similarity coefficient remained less than 50% in all the compositions between the stations, reflecting a heterogeneity in the floristic composition of these stations. The Agglomerative Hierarchical Classification (AHC), revealed a division of species into two main groups 91.56% and 8.43%. Subsequently, Factorial Analysis of Correspondence (FAC) reflects an opening of the environments in the studied groups and installation of species with short life cycle that adapt to local arid conditions. The results obtained provide a diagnosis of the condition of the plant cover in the face of ecological factors, and can be used by foresters to improve the management, protection and restoration of these natural areas