Vegetationsutvecklingen och människans påverkan på vegetationen kring Sojdmyr på Östra Gotland från cal 4000 BP till nutid

Sojdmyr is a small wetland located 3 km east of Lina mire in eastern Gotland, Sweden, in an area highly affected by shoreline displacement. Archaeologists believe Lina mire was once part of a major inland water system used for commerce, and signs from several cultures around the Baltic Sea have been found in the area. This study aims to investigate the vegetational changes in the Sojdmyr area from about 4000 cal BP to the present, as well as discussing the human impacts that have contributed to these changes. Methods used have been pollen analysis, charcoal fragment counting and interpretation of the stratigraphy. The core was dated by correlation the results with other studies from Gotland. From the start of the Bronze Age, ca 4000–3000 cal BP, Sojdmyr was a freshwater lake. The vegetation in the landscape was open, with high presence of thermophilous taxa such as oak and elm and indications of pastoral land use. From the late Bronze Age to the Roman Iron Age (ca 3000–2000 cal BP) the mire Sojdmyr was characterized by fen peat. The thermophilous taxadropped quickly in abundance, whilst taxa more tolerate to cold conditions increased and the area became less open. From the Roman Iron Age (2000–1550 cal BP) to the present, Sojdmyr has changed intermittently between shallow freshwater lake and wetland conditions. According to the pollen analysis the first sign of cultivation in the area appeared with the introduction of rye during the Roman Iron Age, soon followed by barley at approximately ca 1500 cal BP. From the Iron Age to modern times the vegetation in the area became more open with signs of both agriculture and pastoral lands. The pollen record from Sojdmyr suggests that the land use in the area has been affected by shifts in climate during the Migration and Vendel Periods and the Little Ice Age