Contribution à l’étude de l’adaptation des plantes aux environnements arides : caractérisation des traits fonctionnels de Pergularia tomentosa L. dans la région de Ghardaïa.

Abstract

Algeria is highly exposed to the effects of climate change, particularly the increase and prolongation of drought periods, which further weaken arid and semi-arid ecosystems. In this context, the present study aims to analyze certain morphological and functional traits of Pergularia tomentosa collected from the Oued Metlili region (Ghardaïa). Ten leaves were sampled from each individual, for a total of 240 leaves, which were then measured and statistically analyzed. The traits studied were length, width, leaf area, thickness, specific leaf area (SLA), and leaf dry matter content (LDMC).. Statistical analyses included the Shapiro-Wilk test, Kruskal-Wallis test, and Spearman's correlation. The results show that P. tomentosa exhibits a dual drought-adaptation strategy: leaves with increased rigidity that reduce water loss, and marked inter-individual variability. The analysis identifies three independent functional axes—size, water/dry matter content, and leaf shape—as well as a fourth axis related to thickness. It also highlights a trade off between exposed leaf area and structural rigidity, where greater rigidity is associated with reduced relative area. This mechanism contributes to the species’ survival in arid environments.