Reconstructing past land use and vegetation patterns using palaeogeographical and archaeological data: A focus on grasslands in Nynäs by the Baltic Sea in south-eastern Sweden

Past landscape characteristics were reconstructed in Nynäs, south-eastern Sweden, using geographical and archaeological data together with pollen stratigraphy and an existing shore displacement model, with the aim to explore the development of semi-natural grasslands in the area. A 2.3 m peat core was analysed and radiocarbon dated at three levels. The pollen stratigraphy was estimated to start at approximately 3800 14 C years before present (BP), at the end of Late Neolithic. Human activities are evident, from both archaeological findings and pollen analysis, for more than 4000 years. Grazing is apparent, possibly more intense around 3200 14 C years BP, 2500–2600 14 C years BP, 2100–2200 14 C years BP, and 1300/1400 14 C years BP to present day. From 1900±80 14 C years BP and onwards cultivation is intensified at the same time as spruce ( Picea abies) expands. Maps on land-cover distribution in the late 17th century was used as a model for the utilisation of the landscape during the Iron Age. Land-covers on very thin soils were grazed and sometimes mown within the village boundaries, but they were also used for cultivation in narrow strips where bedrock is adjacent to clays. Till and varved glacial clays would have been used for cultivation. A reasonable estimation is that 10% of the study area could have been used for cultivation 1900 14 C years BP, compared to 28% in the end of the 17th century. During the last century there has been a shift towards more arable fields and more forestry. There are 10% open or semi-open grassland left today, and 6% wooded grassland, compared with 47% open or semi-open grassland in the 17th century. Little more than half of the open grasslands are managed today, all by grazing. It is argued that encroachment of trees and shrubs on open or semi-open grasslands will not only reduce species richness in the landscape but also threaten parts of our cultural heritage.