Neolithic land use and forest dynamics on the Swiss Plateau (southwestern Central Europe)

The successional patterns and vegetational processes associated with the Neolithization period remain poorly understood, particularly at high temporal resolution. To address this knowledge gap, decadal-scale, well-dated palaeoecological studies are essential to illuminate this prehistoric tipping point, when economy shifted from collection to production and pristine landscapes were increasingly shaped by human activity.

We analyzed lake sediments from four small lowland lakes on the Swiss Plateau (southwestern Central Europe): Moossee (521 m a.s.l.), Burgäschisee (465 m a.s.l.), Lützelsee (500 m a.s.l.), and Hüttwilersee (435 m a.s.l.). Two of these lakes (Moossee and Burgäschisee) contain annually laminated (varved) sediments, enabling a precise chronological framework. High-resolution palaeoecological analyses, including pollen and microscopic charcoal, were supported by extensive radiocarbon dating. This approach allowed us to investigate the timing and spatial extent of land use phases and plant successional patterns, revealing complex interactions between human activities and climate at an unprecedented temporal resolution.

For millennia, mixed forests dominated by Fagus sylvatica characterized the southwestern Central European lowland vegetation. Our findings indicate that between 6500 and 4200 cal yr BP (4550‒2250 cal yr BCE), three major synchronous forest disruptions occurred. These disruptions coincided with increased fire and agricultural activities around 6400‒6000 cal yr BP (4450‒4050 cal yr BCE), 5800‒5600 cal yr BP (3850‒3650 cal yr BCE), and 5100‒4850 cal yr BP (3150‒2900 cal yr BCE). Land use phases created open areas, typically enhancing plant diversity, and often aligned with the presence of local lake shore settlements. Each phase lasted several decades to centuries. Subsequently, arboreal vegetation recovered, with early successional species such as Corylus avellana and Betula giving way within 100–150 years to late successional mixed beech forests. Abies alba was co-dominant near the Jura and Napf Mountains (Moossee, Burgäschisee) and close to the pre-Alps (Lützelsee) but remained rare in the Lake Constance region (Hüttwilersee).

The palaeoclimatic context suggests that early agrarian societies were highly sensitive to climatic fluctuations. Climate-driven expansions or contractions in agricultural activities, mainly caused by production success or failure, respectively, likely contributed to large-scale, spatially synchronous successional patterns during this transformative period.