Pioneering new approaches to woodland ecology and human activity in medieval Ireland (c.500-1550AD): an investigation using archaeological charcoal

Abstract

The main aim of this thesis was to explore wood resource use, its impact on local woodland and the factors that influenced wood selection strategies during the medieval period in Ireland using the archaeological charcoal record. It examined the functional and cultural factors that influenced wood selection and wood use during a period of dynamic social, economic and political change and provided valuable insights into discreet local and regional patterns of how this raw material was utilised on a spatial and temporal scale. Within a multi-disciplinary framework, this research used and compared the historical, archaeological and palynological evidence to demonstrate the interpretative value of archaeological charcoal for understanding medieval woodland management and resource use. Over 20,000 charcoal fragments were sourced from 49 archaeological excavations carried out across two landscapes located in the south-midlands through counties Tipperary (N8/M8 Cullahill to Cashel Bypass Scheme and Toureen Peckaun) and Kilkenny/Carlow (N9/N10 Kilcullen to Waterford Road Scheme). These sites represented a cross section of early medieval (fifth-twelfth AD) and later medieval (post–twelfth century AD) rural settlement and the diverse range of features typically found associated with them. Fundamental to this research was the use of saturation curve analysis, which has redefined current sample sufficiency recommendations for medieval charcoal assemblages, thus contributing to charcoal sampling methodologies in Ireland going forward. To establish if there were any distinctive patterns within the charcoal record, a number of questions were asked of the data regarding spatial and temporal use of wood, from wood selection processes for specific activities to changes in wood resource use over time. By implementing a series of rigorous statistical tests, the results revealed that wood resource use at the beginning of the early medieval period (c.fifth century AD) was quite diverse, characterised by a rise in ash and fruitwood species, most likely reflecting the extensive period of land clearance that was underway at this time. Between the late seventh and late ninth/tenth century AD, oak use becomes sporadic shifting between being the dominant taxa to being relatively absent in the charcoal record. Wood use at a site fluctuated from being composed of an admixture of taxa to one dominated by a single species (oak). This is interpreted as being a period of when oak reserves were under pressure, during which time measures were put in place to encourage a system of resource sustainability through different forms of woodland and resource management practices. From the tenth century AD, the oak signal rises and remains high and constant into the later medieval period, at the same time other species, such as ash declines in use. The corn drying kiln charcoal data revealed that these quintessential medieval features had a close symbiotic relationship with other on-site activities and were shown to reflect the main changes in wood use variance over time. Wood brought to a site for primary usage (construction, fencing and manufacture) was used, reused or recycled as firewood to fuel other activities, such as corn drying kilns. In addition, a novel approach comparing the charcoal and plant macrofossil assemblages from kilns provided new insights into seasonal wood use at a site. As a result, kilns may be used as a proxy for understanding and interpreting medieval wood use intimately at local level. Wood resource use was therefore culturally driven, representing the human response to a physically changing landscape brought about by their very actions. Bayesian chronological modelling, particularly from the corn drying kiln dataset, provided estimates for when the rise and decline in mixed wood use and oak dominance, a product of anthropogenic factors, is likely to have occurred during the medieval period. This novel approach has in turn the potential to offer new dating parameters for the beginning and end of major socio-economic and political turning points as depicted in the archaeological and historical record. To conclude, the results of this thesis have produced a new body of critically and academically assessed environmental data for the medieval period. This study has contributed new perspectives on medieval woodland and wood use dynamics and the human response to a changing physical and socio-economic landscape. It has pioneered a statistical approach to interpreting medieval charcoal assemblages in an Irish context, highlighted how corn drying kilns can be used as a model for wood resource change at local level and by utilising Bayesian chronological modelling, has established new ways of dating major shifts in wood resource use in line with changes in the historical and archaeological record.