Diversity and functional traits of spontaneous plant species in Algerian rangelands rehabilitated with prickly pear (Opuntia ficus-indica L.) plantations

The prickly pear (Opuntia ficus-indica L Miller) is a xerophytic cactus species widely cultivated in arid and semiarid regions worldwide and used in rehabilitation programs of rangelands in Algeria since 1990. This study analyzed the diversity and functional traits of plant species established in prickly pear plantations growing under arid and semiarid climates. A 3-year plant assessment (2008-2010) was carried out using ecological descriptors (abundance, species richness, diversity indices, disturbance index, and Jaccard index) and plant functional traits (life forms, chorological types, dispersal types, Grime's, Noy-Meir's strategies, and morphological types). The results revealed 36 and 31 species in arid and semiarid rangelands, respectively, with remarkable dominance of therophytic (43.2%) and hemicryptophytic plants (41.1%) growing in the semiarid climatic zone. The Shannon and diversity index showed low values (0.93-1.84 in surveyed rangelands) with a maximum of 2.74 in 2009. The disturbance index ranged between 51% and 55% and the dispersion scheme of diaspores was dominated by anemochorous plants. The chorological analysis indicated that the study plants were oriented towards a Mediterranean pattern in the broad sense. The predominant adaptive strategies of Grime were ruderal-stress-tolerant (RS), competitive-stress-tolerant ((S) and competitive-ruderals (CR), which were attached to the two strategies of Noy-Meir (aridopassives and aridoactives).