The Evidence from Pollen Analysis of a Bronze Age Mound in Bjäre, Sweden
by Jenny Nord Paulsson
The Bjäre peninsula
The Bjäre peninsula is situated in the north west of Skåne, the southernmost county of Sweden. About 14000 BC the ice of the last Ice Age began melting and this area was one of the first Scandinavian parts to be freed from the gigantic ice sheet. The enormous masses of ice had reshaped the area, giving the region a special appearance. In the north of the peninsula, some old rock “survived” the Ice Age and still rise up to heights around 200 meters above sea level. In all, the area hosts seven communities and measures about 200 km2.
The prehistoric heritage from Bjäre is very well preserved, consisting mainly of an unusually high density of Bronze Age graves and places with cup marks. More than 700 mounds from the Bronze Age are known. there are almost as many stone settings from the late Bronze Age and early Iron Age. Several hundreds sites with cup marks have also been noted. The larger carving sites also depict footprints and non-figurative carvings.
From the burial mounds we can gain insight into another kind of heritage from the past - the vegetation of their surroundings. An inventory has shown that the vegetation on the mounds of Bjäre is extremely well preserved from the times before artificial fertilisers were used. It is a flora typical for managed grassland. There are very few visible remains of earlier or later prehistoric date, and the prehistoric layers of visible remains of human activity in the landscape may therefore be summarised as a well-preserved ritual landscapes from the Bronze Age. Around these many soil layers of later farming landscapes have evolved.
The site of Bjäragården and Rishög
Situated in the very centre of the peninsula a 1,5 km long path offers a beautiful
walk into the past at Bjäragården. The road used for hundreds of
years for herding cattle (fägata) leads to Rishög, an impressive Bronze
Age mound with a fantastic panorama vista across Skälderviken and Kullen,
out to the island of Hallands Väderö and north towards Laholm Bay.
At Bjäragården you will also find other remains from the past, e.g.
graves from the Iron Age. Amongst them a stone circle (domarring), ancient rows
of stones, cupmarks (skålgropar) and several other Bronze Age mounds (-hög)
can be seen. One of these mounds is the legendary Elna Mårtens mound,
in which trolls are said to have had their dwelling.
During the ECP project (European Cultural Paths) the Rishög mound was
found to host well-preserved vegetation from times before artificial fertilizers.
The idea was born to check whether the plants could possibly be a link back
to the times when the mound was built. A small excavation took place in order
to collect samples from the mound for pollen analysis.
Pollen analysis from the Bronze Age mound Rishög on the Bjäre-peninsula, Skåne, Sweden.
by Nils-Olov Svensson
Pollen analyses from different layers within archaeological features are considered to be connected to human activity. Archaeological features within layers are often caused by single events; the normal temporal continuity in the sequence of layering is missing or disturbed. The fact that layering is also influenced by the complex environment, makes the interpretation of archaeological features different and more complex than in landscape-connected studies in natural layers. In a grave mound built with surface material from the vicinity, most probably brought there as turf, the pollen content may give information about the local vegetation from where the turf once were taken.
The Rishög analysis
Three different layers could be distinguished in the mound;
the former ground level and underground (layer D)
the mound filling (layer B)
surface-earth (layer A).
The samples were collected from a small trench, which measured 3 x 0,5 meters. The samples were taken in the eastern part of the mound, closest to its centre. Here the trench was deepest, allowing collection of undisturbed mound filling.
The fossil/historic landscapes
Pre-mound (layer D): Before being used as a burial site, the sample area was previously a meadow with lime trees. Based on the pollen analysis, the flora directly at the burial site is somewhat different to the vegetation that grew in its surrounds. This may be because of the thin layer of soil here or the lack of a lime tree, which we assume, was only found directly on the burial mound. The occurrence of Polypody also suggests that the underlying rock was partly visible.
The filling (layer B): A general conclusion from the pollen analysis is that the mound's filling originates from very intensively grazed grassland. This is shown by the low frequency of tree pollen in combination with very high concentrations species, which are favoured by grazing. Hewever, nothing contradicts that the upper level of layer D and layer B are of the same age.
The surface (layer A): This layer represents the vegetation that has been growing on the mound since it was built. The sample holds evidence of heatherland, which no longer exists today, but might have dominated the area some hundred years ago.
The steady occurrence of Polygonum persicaria (lady thumb (eng), Floh-Knöterich (German)) in samples of layer B is noteworthy. Polygonum persicaria is an annual weed, common in crop fields, but also grows in humid areas as ditches and marches. However, it is not likely that Polygonum persicaria grew on the grazing land close by, which on the other hand is the most plausible origin for the filling of the mound. The inventory of today's flora on Bronze Age mounds on Bjäre (Gustafsson 1998) does not show any occurrences of Polygonum persicaria. One explanation might be that the plant has been able to establish itself as a flowering weed during the time when the mound was being built. The occurrence of the plant in all samples from layer B shows that the building of the mound was slow enough that Polygonum persicaria could continuously establish itself. This would suggest, that the mound was not completely built within one winter season.
References and proposals for further reading:
Andersen, S. T. 1979. Identification of wild grass and cereal pollen. Danm Geol Unders Årbog 1978, pp 69-92
Andersen, S. T. 1979. Brown earth and podzol: soil genesis illuminated by microfossil analysis. Boreas 8, 59-73.
Andersen, S. T. 1986. Palaeoecological studies of terrestrial soils. 1: Berglund, B. E. (ed): Handbook of Holocene Palaeaecology and Palaeohydrology. John Wiley & Sons. 165-177.
Andersen, S. T.1996. Geobotaniske Undersøgelser af Kulturlandskabets Historie. Pollenanalyser fra gravhøje og søer i 1995. Udarbejdet for Skov- og Naturstyrelsen. Danmarks og Grønlands Geologiske undersøgelse. Rapport 1996/8. 55 sid.
Behre, K. E. 1981. The interpretation of anthropogenic indicators in pollen diagrams. Pollen et spores. 23. 225-245.
Berglund, B. E. 1969. Vegetation and human influence in South Scandinavia during prehistoric time. Oikos Suppl. 12 pp 9-28.
Berglund, B. E. (Editor) 1985. Handbook of Holocene Palaecology and Palaeohydrology. John Wiley & Sons Ltd.
Berglund, B. E. 1986. The Cultural Landscape in a Long-Term Perspective. Methods and Theories Behind the Research on Land-Use and Landscape Dynamics. In Nordic Late Quaternary Biology and Ecology (L.-K. Königsson, Ed.) Striae vol. 24, pp. 79-87.
Berglund, B. E., Malmer, N. & Persson, T. 1991. Landscape-ecological aspects of long-term changes in the Ystad area. In: Berglund BE (ed) The cultural landscape during 6000 years in southern Sweden - the Ystad Project. Ecological Bulletins 41: 405424
Berglund, B. E. & Ralska-Jasiewiczowa, M. 1986. Pollen analysis and pollen diagrams. In: Berglund, B. E. (ed) Handbook of Holocene palaeoecology and palaeohydrology. Wiley, Chichester, pp 455-484
Birks, H. J. B. & Birks, H. H. 1980. Quaternary palaeoecology. Edward Amold, London.
Björkman, L. 1991. Vegetationshistorisk undersökning av en förhistorisk jordmånsprofil begravd under en stensträng i Rösered, Västergötland. Exemensarbeten i geologi vid Lunds universitet nr 35.
Björkman, L. 1992. Vad kan en jordmånsprofil säga om vegetation och markutnyttjand? Exemplet Röseryd i Västergötland. Bebyggelsehistorisk tidskrift. 23. pp.27-38.
Björkman, L. 1998. Bokens historia i södra Sverige - en litteraturöversikt. Svensk Botanisk Tidskrift 91, 573-583.
Björkman, L. & Bradshaw, R. 1996. The immigration of Fagus sylvatica L. and Picea abies (L.) Karst. into a natural forest stand in southern Sweden during the last 2000 years. Journal of Biogeography 23, 235-244.
Dimbleby, G. W. 1957. Pollen analysis of terrestrial soils. New Phytologist56, 12-28.
Dimbleby. G. W 1985. The Palynology of Archaeological sites. In Studies in Archaeological Science. Academic Press, Inc, London 1985. 176 pp.
Faegri, K. & Iversen, J. 1989. Textbook of pollen analysis, 4th edn, by Faegri K, Kaland PE, Krzywinski K. Wiley, New York
Gustavsson, M. 1998. Inventering av Vegetation och Flora på Bjärehalvöns bronsåldershögar. Instutitionen för Växtskyddsvetenskap, Alnarp. 48 sid.
Havinga, A. J. 1984. A 20-year experimental investigation into the differential corrosion suscebtibility of pollen and spores in various soil types. Pollen et Spores 26, 541-558.
Iversen, J.1941. Landnam i Danmarks stenalder (Land occupation in Denmark's Stone Age). Dan. Geol. Unders. 2:66. 68 PP.
Korsmo, E. 1926. OGRÄS ogräsarternas liv och kampen mot dem I nutidens jordbruk. Albert Bonniers förlag, Stockholm. 410 sid.
Lagerås, P. 1996. Vegetation and land-use in the Småland Uplands, southern Sweden, during the last 6000 years. LUNDQUA Thesis 36: 1-39
Lagerås, P. & Sandgren, P. 1994. The use of mineral magnetic analyses in identifying middle and late Holocene agriculture - a study of peat profiles in Småland, southern Sweden. J Archaeol Sci 21 pp 687-697.
Lagerås, P. & Regnell, M. 1999. Agrar förändring under sydsvensk bronsålder - en diskussion om skenbara samband och olösta gåtor. I: Olausson, M. (red.) Spiralens öga - 20 artiklar kring aktuell bronsåldersforskning. Riksantikvarieämbetet, Avdelningen för arkeologiska undersökningar, Skrifter 25, s. 321-335.
Moore, P. D., Webb, J. A. & Collinson, M. E. 1991. Pollen analysis, 2nd edn. BlackwelL Oxford
Nilsson, S-O. 2000. Pollenanalytisk undersökning av jordlager i Rishög, Bjäragården. Eslöv.
Regnéll, J. 1989. Vegetation and land use during 6000 years. Paleoecology of the cultural landscape at two lake sites in southern Skåne, Sweden. LUNDQUA Thesis 27.
Welinder, S. 1983: The ecology of long-term change. Acta Archaeol. Lundensia, Ser 8° Minore 9. 115 pp.
Welinder, S., Pedersen, E. A. & Widgren, M. 1998. Jordbrukets första femtusen år, 4000 f. Kr.-1000 e. Kr. Natur och kultur/LTs förlag. Borås. 504 sid.