A travers l'analyse de matériel macrobotanique (charbon et graines / fruits) issus de trois sites majeurs du Later Stone Age (LSA) d'Afrique australe, cette étude s'intéresse à reconstituer les conditions environnementales durant l'Holocène dans la région, en particulier au cours des deux à trois derniers millénaires. L'étude de ce matériel, accompagné de la constitution d'une collection moderne de références de la végétation du bassin Kgalagadi, vise à mieux cerner l'impact quel'environnement a pu avoir sur les sociétés humaines (subsistance, peuplements, etc.) à une période-clé du (LSA), qui marque l'émergence des pratiques pastorales dans la région. L'étude des environnements est ici primordiale pour interpréter les conditions qui ont pu favoriser l'arrivée de ces premiers éleveurs et leurs lieux d'installation. En complément, une approche ethnographique a été menée, en travaillant avec les communautés locales dans la région de l'Erongo en Namibie, qui peuvent aider à comprendre et reconstituer les pratiques passées d'utilisation de la végétation. / Through macrobotanical (wood charcoal and seeds / fruit) analysis from three major Later Stone Age (LSA) sites located in the Kgalagadi Basin in southern Africa, this study is interested in reconstructing the environmental conditions during the Holocene in the region, in particular in the last two to three millennia. Initially this work couples archaeological macrobotanical analysis with the construction of modern reference material in an effort to trace the environmental / vegetal evolution as well as to comprehend socio-ecological and socio-environmental dynamics in Southern Africa during the late Holocene. The scope of this study covers the period spanning the last 3000-2000 years, with the main objective of understanding what relationships humans had with their environment at a time linked with the arrival or the appearance of the first herding practices in that part of Africa. These herding practices are believed to be accompanied by significant human movement from eastern or central Africa southwards. Favourable environmental conditions may have influenced their routes as well as settlement choices, and these are aspects that this archaeobotanical study aims to address. This study also employed an ethnographic approach, working with local communities in the Erongo region of Namibia, so as to make inferences to past vegetation utilisation practices while at the same time discerning and reconstituting past human activities.