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How forest growth shaped Iberomaurusian lifeways in northeastern Morocco
The Iberomaurusian, a prehistoric archaeological culture that flourished in North Africa between 25,000 and 10,000 years ago, underwent significant lifestyle changes during the Greenland Interstadial 1 climate phase, which favored the expansion of forest cover. In a groundbreaking study based on excavations at Morocco's Taforalt and Rhafas sites, a team of Moroccan and international researchers reconstructed these environmental and cultural shifts.
Their initial findings reveal a close connection between forest expansion and altered land-use behaviors, profoundly impacting diet. Published on Thursday, June 12, 2025, the study, conducted by researchers from American, French, German, and British universities alongside Morocco's National Institute of Archaeology and Heritage Sciences (INSAP), notably identifies early exploitation of storable plant foods like oak and pine at Taforalt, coinciding with intensified site occupation.
Amidst abundant local nut-bearing trees and a regional rise in human population density, social organization in the region likely became more complex, according to the research titled « Expansion of forest cover and coeval shifts in Later Stone Age land-use at Taforalt and Rhafas Caves, Morocco, as inferred from carbon isotopes in ungulate tooth enamel».
This period, known as the Late Stone Age, featured distinctive stone tools, organic materials, and symbolic artifacts, but more importantly, it marked significant shifts in land use compared to earlier phases. There was a clear reorganization of resource exploitation and group mobility, reshaping usage patterns at sites such as Taforalt, Ifri el Baroud, and Ifri n'Ammar.
The Late Stone Age also saw increased accumulation of anthropogenic sediments dominated by ash, reflecting higher occupation intensity and greater use of fire. Additionally, more cemeteries emerged, such as those at Taforalt and Afalou in Algeria, with at least 90 and 58 individuals buried, respectively.
At Taforalt, evidence points to a growing reliance on plants in the human diet, supported by ground stone tools, abundant macrobotanical remains, stable isotope analysis of human teeth, and increased dental caries. Expanded diets in northeastern Morocco are also indicated by significant land snail remains found alongside ash layers at Ifri el Baroud, Ifri n'Ammar, and Taforalt.
Samples from Barbary sheep and gazelles at Taforalt and Rhafas show a 1.5 to 2‰ decrease during the Greenland Interstadial 1. However, equids and alcelaphines, which prefer open grassy areas, did not show such changes, suggesting that wooded mountain and hill habitats were primarily affected by the GI-1 climate interval locally.
Researchers argue this points to high-altitude forest expansion and canopy filling near Taforalt and Rhafas during this time. While the broader geographic extent remains unclear, similar changes are noted at Ifri el Baroud, 80 km west of Taforalt. These changes coincide with the start of the gray stratigraphic series at Taforalt, reflecting marked shifts in hunter-gatherer land-use behaviors.
These shifts include intensive use of acorns and pine nuts, indirect evidence of plant processing and storage, high artifact and food waste concentrations despite heavy sedimentation, and the emergence of a cemetery at the cave's rear.
Early Signs of Food Transformation and Storage
The researchers interpret these archaeological indicators as evidence of stronger, more permanent ties to the site. Collectively, these features suggest longer stays at Taforalt, with plant food exploitation, especially storable forest resources, as a major activity, accompanied by an expanded diet and increased investment in food processing.
The increased tree productivity during GI-1 likely contributed to the intensive use of the site. Coupled with rising regional human population densities and higher primary productivity, these factors supported stronger human presence not only at Taforalt and Rhafas but across present-day Morocco.
The study also notes preliminary signs that these behavioral patterns emerged during the later, cooler, and drier Heinrich 1 phase, consistent with data from Taforalt's rich archaeological record. Notably, the increased forest productivity during GI-1 coincided with intense acorn consumption, which was processed and likely stored.
These starchy foods are rich in fermentable carbohydrates, which can accelerate enamel demineralization, especially when ground or cooked, explaining the dental evidence in human remains from the period, alongside indications of food drying for storage.
To further clarify landscape evolution and decisive changes in land use by hunter-gatherers during this critical interval, researchers emphasize the need for additional dating and paleoenvironmental analyses. These next steps will enable more precise timing of these developments.
