Applicability of CSR strategy schemes at the local intraspecific level: a case study from the Beni Bousera region (Northern Morocco)

Plant species in Mediterranean ecosystems are expected to respond differently to potent environmental filters, such as climate aridity and harshness of the soil, through different functional strategies. However, intraspecific variability on a local scale has not received sufficient attention in the study of CSR strategies. In this study, we compared the leaf features and CSR strategy of seven common woody species located on ultramafic and neighboring non-ultramafic soils in the Beni Bousera region of northern Morocco. Firstly, a physico-chemical analysis of soil composition was carried out to assess the differences between the two sites. Secondly, fresh weight, dry weight and leaf area were measured, and CSR strategies were calculated for 10 individuals per species to assess intraspecific variability. The results highlighted significant differentiations between the two soil types, attributed mainly to a moderate serpentine effect expressed as Ca:Mg < 1 in the ultramafic site, as well as differences in soil texture. In response to these adverse conditions, we found substantial intraspecific variability in leaf traits, accompanied by changes in CSR strategies for some species. At site U, Quercus coccifera adopted an S strategy, while Cistus salviifolius behaved as an S/SC species. Lavandula stoechas and Teucrium fruticans showed significant inter-individual variability, while Cistus atriplicifolius, Phillyrea latifolia and Erica arborea adopted the same strategy at both sites. Our research contributes to the enrichment of CSR databases and underlines the applicability of the CSR strategy scheme at the local intraspecific level.