Fencing land impacts on plant biodiversity and argan trees dynamic in the Ida-Ou-Tanane (central western of Morocco)

Abstract

The argan trees are subject to strong anthropgenic pressure that prevents its natural regeneration. This study aims to evaluate the effect of lands fencing on the redynamization of the argan trees through analyzing and comparing the specific richness in two closer parcels. The first parcel have been fenced since 2004, whereas the second one is an open land. In this study, the floristic diversity indices were investigated and compared based on field inventory from both parcels. The results obtained show the beneficial effect of the fence on the dynamics of the vegetation. The plant specific richness is higher for the fenced parcel than unfenced parcel (37 and 21 species, respectively). For the fenced parcel, the maximum diversity index is about 3.61, while it is about 3.04 for the unfenced parcel. The Shannon-Weaver index (H’) and the evenness (E) are also higher for the fenced parcel where the cover rate is 57% compared to 32% for the unfenced parcel. The average of the computed argan trees, in the fenced parcel, is 116 trees/ha of size ranging between 2 to 5 m. For the unfenced parcel, the average is 83 trees/ha of size of 4 m. Additionally, inside the fenced parcel, the natural regeneration by seedling is well marked, where considerable number of argan trees towere identified during field survey. These results highlight the importance to use fencing in the generation of the endemic plants.