Central Norway sedaDNA study
Sedimentary ancient DNA (sedaDNA) has been proposed as a key methodology for reconstructing paleoclimates and biodiversity over time. To a lesser extent, it has been explored as a complementary tool for reconstructing human-driven local environmental changes over time, such as those explored in open air archaeological sites. Our study employs a sedaDNA metagenomic approach to investigate land use and environmental change at the archaeological site of Torgaårdsletta in central Norway, spanning from the Bronze Age through to the Medieval period. Stratigraphic sedaDNA samples reveal temporal shifts in plant and microbial communities, reflecting evolving human practices and climatic conditions. Notably, we were able to detect aDNA from domesticated animals at various intervals throughout the layers. Bone material is not usually preserved in such archaeological sites in Norway, thus sedaDNA analyses offer valuable insights into signs of land clearance, cultivation and, significantly, animal husbandry in the region. Additionally we find a significant reduction in microbial and plant diversity during periods of climatic upheaval—such as the AD 536–540 volcanic event—which correlates with landscape and societal adjustments. The findings demonstrate that sedaDNA complements traditional proxies, providing high-resolution insights into past land use, environmental interactions, and societal organization. The successful extraction of ancient genetic material underscores sedaDNA's potential to reconstruct dynamic prehistoric landscapes and anthropogenic impacts, offering further potential for understanding long-term human-environment relationships.