Land-use history in Gamla Uppsala, southeast Sweden, established on subfossil Coleoptera remains and pollen in fluvial deposits

摘要

Insect and pollen remains in fluvial sediments from the stream bank of river Fyris and one tributary brook, Samnan, in south-eastern Sweden, were studied. The deposits cover the last 400 years, according to ~(14)C dates. The insects, dominated by subfossil beetles, originate foremost from stream environments, indicating aquatic development. Scarce finds from a wider area are recorded, particularly in samples from the banks of Fyris river there is a strong influence from surrounding land. Pollen originates from the surrounding cultivated field and grazing areas as well as wet meadows. The domainance of the stream environment changes along the examined core. The land-use history as it is reflected by deposited subfossils are compared with old maps from the area. It is demonstrated that the source areas for subfossil beetle and pollen have changed over time. Consequently, it is difficult to estimate the area for which the land-use history is accurate. For test purposes, the Mutual Climatic Range (MCR) method has been used for reconstructing mean temperatures based on the beetle record.