Vegetationshistorisk undersökning av en förhistorisk jordmånsprofil begravd under en stensträng i Rösered, Västergötland

Summary: This study deals with local vegetation and land use history contemporary with prehistory clearance cairns and stone walls in the area of Rösered, province of Västergötland, south-western Sweden. Pollen analysis of a humusrich layer buried below a stone wall was carried out. It revealed that: -the layer developed as mull, first in open woodland dominated by birch, later in grassland with some scrubs of birch. -the pollen stratigraphy was dominated by Betula, but that Poaceae, Calluna, Polypodiaceae and Tubuliflorae also made up a large part of the pollen content. -there was some arable land in the vicinity, but the pollen frequencies of Cerealia and weeds were low, so the soil profile was probably never tilled or cultivated. -the area with clearance cairns probably consisted of a mosaic of pastures, fallow and small tilled fields. According to archaeological investigations the soil profile probably developed during the Bronze Age, or early Iron Age, and became buried when the stone wall was laid down, likely during the early Iron Age. The fields with c1earence cairns are by archaeologists believed to represent areas of extensive land use, probably with coppice, fallow and small tilled areas. No certain correlation with regional pollen diagrams has been possible to accomplish, because the pollen diagram from Rösered only represents rather local changes in the vegetation. The pollen content implies that the soil profile definitely developed after the pollen zone AT 2, but before the regional rise of Picea, c. 400 -500 A D. It is likely that the soil profile developed c. 2300 -2100 14C-years B P during the early Iron Age, c. 300 -100 B C, because the pollen content has many similarities with the pollen content found in Lake Tranemosjön from this time. The archaeological hypothesis about extensive land use could be confirmed. It is likely that the fields with clearance cairns in Rösered were dominated by pastures. The arable fields were small and only tilled a few years each time. They later became fallow, most likely as pastures with some scrubs of birch.