Phenological Factors and Subsistence Strategies in Changing Environments: A Case Study of Late Pre-Pastoral/Late Acacus Sites in the Libyan Sahara during the Early–Mid Holocene

Abstract

This study evaluates the phenological mechanisms and factors that drove changes in spatial organization and economic strategies at Pre-Pastoral/Late Acacus habitation sites occupied by pottery-using hunter-gatherers in the Libyan Desert. These sites provide crucial chronological and economic evidence for understanding paleoclimate dynamics in the region. An integrative methodology was employed, combining palynological analysis with historical, archaeological, and paleoecological approaches. A comparative framework across both temporal and spatial scales was applied to examine the interactive relationship between climatic fluctuations and human adaptive strategies, linking these patterns to ecological, stratigraphic, and typological changes observed in both neighboring and more distant areas within the same chronological context. The results indicate that declining humidity during the Early–Middle Holocene disrupted seasonal vegetation cycles, affecting the availability of natural resources. In response, hunter-gatherer groups adopted a semi-sedentary spatial organization in a strictly mountainous environment, characterized by more complex architectural structures and a specialized subsistence economy. This economy relied on a wide range of plant and animal resources, the production of large sandstone flakes, the use of microlithic toolkits, and various manufactured items such as baskets and bone tools. Pottery was widespread and decorated Dotted Wavy Line pottery, and in some cases, dotted-line patterns. The study concludes that phenological changes were a major driver in reshaping the economic and social structures of Late Acacus communities, shaping human adaptive strategies and resource management in an increasingly arid desert environment.