Ecological assessment of wetland suitability for early cultivation in the Dutch lowlands

Environmental suitability for cultivation is central to understanding the pace and character of the Mesolithic–Neolithic transition in the Dutch lowlands. Although cultivation at Swifterbant sites is well documented, it remains unclear how widespread suitable conditions were beyond settlement locations, when they emerged, and how long they persisted. This limits assessment of the extent to which wetland ecology may have constrained or enabled the expansion of cultivation within the wider landscape. This study evaluates cultivation suitability using plant macroremains, pollen, phytoliths and charred herbaceous plant tissues from five cores spanning levee, channel and floodbasin contexts within a submerged Middle Holocene channel–levee system of the palaeo-Vecht in the IJsselmeer region. Channel and floodbasin environments remained waterlogged and dominated by aquatic and marsh vegetation, whereas levees followed contrasting ecological trajectories. Despite being separated by only c. 2 km, the seaward levees remained hydrologically dynamic, while the landward levee entered a prolonged phase of reduced sediment accumulation, surface exposure and pedogenic development after c. 4800 BCE. This interval provided the clearest conditions suitable for cultivation and coincides with increased burning, non-diagnostic cereal-type phytoliths and charred tissues, and independently identified evidence for tillage. The results indicate that cultivation opportunities were spatially restricted and tied to prolonged surface stability and suitable hydrological conditions. Yet, the persistence of favourable conditions on the landward levee shows that wetland constraints were not absolute. This landscape heterogeneity could therefore have limited the spatial extent and continuity of cultivation while allowing farming to be incorporated selectively alongside wetland-resource use.