Rôle du dromadaire dans la régénération et la prolifération du couvert floristique des parcours du Sahara septentrional algérien

Abstract

The Saharan milieu contains floristic acclimatized resources, surviving with adaptations forms, and are, essentially, valued by the camel, only livestock species adapted to this environment and living in extensive mode. The aim of this study is to understand the impact of the camel in the persistence and regeneration of the desert ecosystem and, by identifying, quantifying and by germinating the seeds of the species that can be dispersed by this animal defecation. In this sense, we have made the samples fecal collection of this animal through six different types of rangelands Saharan camels and analyze their contents in seeds for submission to the germination tests (in the laboratory) compared with seeds directly collected from mothers species in pasture. So as to study and quantify its role in the seeds dispersal and germination after passing in his digestive tract, in addition, a portion of the collected feces was cultivated in pots at greenhouse, in order to know the effect of gut passage on the germination and seedling growth. The floristic study allowed to identify 31 of 39 species from faeces, divided into 15 perennial and 16 ephemeral belonging to 18 botanical families, which was in good condition. Although the analysis of the seeds quantity dispersed by the dromedary and their temporal distribution shows that the summer is the most represented season because it coincides with the general maturation of seeds produced in large numbers. The examination of morphological seeds traits shows that the majority of species dispersed by dromedary with small seeds, a very light weight, brown and yellow color, and usually spherical shape. What appears a very effective mechanism of species adaptation in dry lands. The germination study indicates that 22 species have retained their ability to germinate after passing through digestive tract, owned 9 botanical families, 50% of which are ephemeral against 32% perennials and 18% undetermined. Indeed, we report that the camel has the potential and the dispersion capacity of 4 highly appreciated species, improving and stimulating 3 of the Fabaceae family (Argyrolobium uniflorum, Astragalus cruciatus and Astragalus ghysensis) and only one of the Cistaceae family’s (Helianthemum lippii). The dromedary, share of their food behavior and dispersion seeds over long distances, remains unique ecological species of the vast Saharan environments.