The Importance of Analysing Waterlogged Wooden Artefacts and Environmental Conditions when Considering their In Situ Preservation

Abstract The importance of analysing the state of preservation of waterlogged wooden artefacts as part of the in situ monitoring programme at the Iron Age site of Nydam is discussed. Determination of density, wood cell wall components (cellulose and lignin), coupled with macroscopic and microscopic analysis showed that artefacts were completely degraded, and that it was only the lignin rich compound middle lamella and water in the cell wall and lumen which retained the shape of the artefacts. Erosion bacteria (cellulose degraders) were identified as the main cause of deterioration of the wood. With no cellulose remaining, and under the prevailing conditions, it is unlikely that the wood can act as a substrate for further microbial deterioration. One of the major threats to the future preservation of wooden artefacts is drainage. Experiments to simulate the effect of desiccation on artefacts showed that there was the possibility of fungal deterioration by white rot species, yet more seriously, artefacts would suffer immediate collapse with loss of archaeological information.

[1]  Robert A. Blanchette,et al.  Biological degradation of wood. , 1990 .

[2]  B. Ahring,et al.  Identification of bacterial cultures from archaeological wood using molecular biological techniques , 2004 .

[3]  B. Christensen.  DEVELOPMENTS IN THE TREATMENT OF WATERLOGGED WOOD IN THE NATIONAL MUSEUM OF DENMARK DURING THE YEARS 1962–69. , 1970 .

[4]  Henry Chapman,et al.  Monitoring and Modelling Saturation as a Proxy Indicator for in situ Preservation in Wetlands—a GIS-based Approach , 2002 .

[5]  Roger M. Rowell,et al.  Archaeological wood: properties, chemistry, and preservation. , 1989 .

[6]  Norman E. Hickin,et al.  The Insect Factor in Wood Decay: An Account of Wood-Boring Insects with Particular Reference to Timber Indoors , 1968 .

[7]  John C. F. Walker.  Water in wood , 2006 .

[8]  Alfred J. Stamm,et al.  Wood and Cellulose Science , 1964 .

[9]  Henry Chapman,et al.  In situ preservation as a dynamic process: the example of Sutton Common, UK , 2001, Antiquity.

[10]  Mark Jones,et al.  Structure and degradation process for waterlogged archaeological wood , 1990 .

[11]  C. Björdal,et al.  Waterlogged archaeological wood—a substrate for white rot fungi during drainage of wetlands , 2002 .

[12]  P. Jensen,et al.  Environmental Monitoring at Nydam, a Waterlogged Site with Weapon Sacrifices from the Danish Iron Age. I: A Comparison of Methods Used and Results from Undisturbed Conditions , 2004 .

[13]  L. E. Wise,et al.  A CHLORITE HOLOCELLULOSE, ITS FRACTIONATION AND BEARING ON SUMMATIVE WOOD ANALYSIS AND STUDIES ON THE HEMICELLULOSES , 1946 .

[14]  F. Hunter.  The Spoils of Victory. The North in the Shadow of the Roman Empire . Edited by L. Jørgensen, B. Storgaard and L.G. Thomsen. Nationalmuseet, Copenhagen, 2003. Pp. 452, illus. Price: €25.00. ISBN 87 7602 006 1. , 2005, Britannia.

[15]  Mark Robinson,et al.  Saving the Sweet Track: The in situ preservation of a Neolithic wooden trackway, Somerset, UK , 2000 .

[16]  Roger M. Rowell,et al.  Archaeological Wood: Properties, Chemistry, and Preservation , 1990 .

[17]  C. Skaar.  Water in wood , 1972 .

[18]  A. J. Panshin,et al.  Textbook of Wood Technology , 1964 .