Preservation of fungi in archaeological charcoal

During the analysis of wood charcoal remains from archaeological sites, it is common to find different microorganisms and different forms of degradation present in the plant tissue. However, one may encounter difficulties when attempting to identify these microorganisms and determine when their attack occurred. This paper focuses on preservation aspects related to the microorganisms in wood and demonstrates the structural changes that take place in different types of decayed wood after it was converted into charcoal. The study seeks to determine whether the microbial attack found in archaeological woods took place before the burning of the wood or after. Burning experiments were conducted using wood that had been decayed by various types of fungi including white-rot, brown-rot, and soft-rot. The laboratory burnt wood samples showed decay patterns that were comparable to those observed in archaeological charcoal samples, indicating that signs of fungal infestation and features of decay can be preserved after burning with micromorphological details of mycelium and cell wall attack evident. This indication may provide important information related to the gathering of deadwood as fuelwood. In addition, examples of decayed wood preserved in archaeological charcoal assemblages are described. Their relationship to the archaeological context and environmental conditions may suggest different interpretative models concerning wood management strategies applied by past societies.     

Archaeobotanical inference of Bronze Age land use and land cover in the eastern Mediterranean

Charcoal and charred seeds at five Bronze Age archaeological sites discern ancient land use in the eastern Mediterranean. Seed frequencies of orchard crops, annual cereals and pulses, and wild or weedy plants are used to characterize plant utilization at different archaeological sites on the island of Cyprus, in the Rift Valley of Jordan, and in the Jabbul Plain and along the upper Euphrates River valley in Syria. Seed to charcoal ratios provide proxies to determine the relative usage of dung versus wood for fuel across the ancient Mediterranean landscape. Greater charcoal and lower charred seed values are interpreted to represent a wooded environment, while higher amounts of charred seeds and minimal wood charcoal suggest a much great use of dung as a fuel source. Interestingly, Politiko-Troullia (Cyprus, Cypriot archaeological sites are, by convention, named for the nearest modern village (Politiko), followed by an italicized toponym (Troullia) referring to the plot of land that incorporates the site) has the lowest seed to charcoal ratio, suggesting its residents primarily burned wood and that the landscape surrounding Troullia remained relatively wooded during the Bronze Age. In contrast, villagers at Tell el-Hayyat (Jordan) utilized a mixture of wood and dung, in contrast to Tell Abu en-Ni’aj (Jordan), and especially Umm el-Marra and Tell es-Sweyhat (Syria), where inhabitants relied solely on dung fuel. Comparative analysis and interpretation of seed and charcoal evidence thus illustrates the variety of fuel use strategies necessitated by the dynamic and diverse Bronze Age landscapes of the Eastern Mediterranean.     

Charcoal scarcity in Epigravettian settlements with mammoth bone dwellings: the taphonomic evidence from Mezhyrich (Ukraine)

Fuel management during the Paleolithic periods is an important issue to understand past human subsistence. Numerous Palaeolithic sites relate an abundance of burnt bones in hearths and an absence or scarcity of wood charcoals, which leads studies to focus on burnt bone remains and the use of bones in hearths. Few works take into account the micro-residues of wood charcoals which can still be present in hearth areas and excavated sediments. We studied the Epigravettian site with mammoth bone dwellings of Mezhyrich (Ukraine) previously characterized by its high content of burnt bones and an “absence” of wood charcoal during the so-called mammoth steppe. The presence or absence and proportions of both wood charcoals and burnt bones were quantified in macro-, meso- and microscale sediment size fractions by an image analysis method. Our results show that excavations during field-works at Mezhyrich give only a partial image of the original anthracological record and that most charcoal materials are lost with standard archaeological and anthracological approaches. The scarcity of charcoals in this site was possibly due to an important mass reduction accentuated by the addition of bones in hearths. By applying our protocol we recovered a significant amount of wood charcoals which provides the first ¹⁴C dates from charcoals at Mezhyrich. Numerous charcoals are identified contributing subsequent information about vegetation, environment and burning practices. They indicate, by comparison with pollen data already collected, the presence of forest patches in a mammoth steppe landscape, which might have influenced the collecting behavior of Epigravettian populations.     

Fuelwood collection as daily practice: a wood charcoal study for the colonial period North Carolina Piedmont

ABSTRACT

European colonization brought innumerable changes and choices to Native groups across the Southeast. Scholars continue to examine the various ways communities navigated these disruptions. Studying the remains of daily practice offers a window into how communities negotiated continuity and change. Wood charcoal, representing the remains of daily fires, provides an important, but underutilized, method for examining people’s daily routines and interactions with their surrounding landscapes. This paper examines wood charcoal assemblages from several sites in the North Carolina Piedmont that span the precontact to early colonial periods (AD 1400–1705). Fuelwood collection models are used to consider the environments, practices, and preferences that influenced the composition of wood charcoal assemblages. Comparison of these datasets shows a consistent significant pattern of high-quality fuelwood selection with additional patterns potentially related to long-term use of the same environment and factors related to colonialism. Altogether, these patterns suggest continuity of some daily practices despite disruptions to other aspects of life.     

Selective woodland exploitation for charcoal production. A detailed analysis of charcoal kiln remains (ca. 1300–1900 AD) from Zoersel (northern Belgium)

A detailed study of charcoal burning activities has been made for the Zoersel forest (Northern Belgium) based on an inventory of charcoal kiln remains, the analyses of wood charcoal and other charred botanical macroremains and radiocarbon dating of 10 of these kilns. Age determination of the youngest kilns was refined by dendrochronological analysis of trees growing on top of these kiln sites. The results show that, although many kilns were found, charcoal was produced in Zoersel only at certain moments during late and post-medieval times suggesting that charcoal burning was not a part of the regular management practice of these forests. The wood used for the production of charcoal mainly consists of taxa of alluvial (alder) forests while the kilns are situated on sites that currently are rather dry, with an oak dominated vegetation. For the older kilns, this contrast could be explained by an important change in local soil conditions. The younger kilns may be related to the conversion of alder woodland to grassland in the lower parts of the domain, with the kilns being constructed in the nearby dryer woodland areas.     

Identifying archaeological wood stack charcoal production sites using geophysical prospection: magnetic characteristics from a modern wood stack charcoal burn site

Charcoal making was a common process in the woodlands of Britain for many centuries. However, historic ‘wood stack’ production sites are difficult to identify. This paper tests the hypothesis that geophysical survey is an appropriate method for the discovery and identification of archaeological charcoal making sites. A traditional wood stack charcoal kiln was constructed in Low Staindale, Dalby Forest, near Pickering, North Yorkshire, to investigate the charcoaling process and the effect of low-temperature carbonisation on the magnetic properties of the soil underlying the kiln. The results from temperature monitoring (within and beneath the charcoal stack) throughout the charcoaling process, geophysical surveys across the charcoal kiln platform, and laboratory analysis of soil and ash samples, are presented. The degree to which the magnetic properties of the ground beneath the charcoal kiln had been enhanced as a consequence of this low-temperature process is discussed. Whilst some magnetic enhancement to the soil beneath the kiln platform was recorded, enhancement appears to be the result of contamination from the wood stack sealing material rather than the effect of heat transfer resulting from the charcoaling process. The results suggest that whilst historic wood stack charcoal production sites are likely to remain an enigmatic and under-reported feature in the archaeological landscape, geophysical prospection does have the potential for identification of these sites.     

The 13th century polynesian colonization of Hawai’i Island

We assess 926 radiocarbon dates from Hawai’i Island, the largest assemblage of dates compiled from a single island in Oceania. Based on a classificatory approach that arranges the dates based on their reliability, accuracy, and precision, our results indicate that the most reliable estimate for the initial Polynesian colonization of Hawai’i Island is AD 1220–1261, ∼250 to 450 years later than the current consensus. This conclusion is strikingly convergent with recent estimates for the colonization of remote East Polynesia. Our analysis highlights the need for wood charcoal identification to insure selection of short-lived plants/plant parts for radiocarbon dating, and that a reliance on dating unidentified wood charcoal is a waste of resources that only serves to retard progress in refining the settlement chronology of Hawai’i Island and other locations.     

Charcoal in alluvium of mountain streams in the Bieszczady Mountains (Polish Carpathians) as a carrier of information on the local palaeoenvironment

Fragments of charcoal are present in floodplain alluvium of the San and Strwi?? rivers in the Polish part of the Bieszczady Mountains, Polish East Carpathians. They occur as single clasts or in lenses in the basal part of fine-grained alluvium, together with unburnt wood debris, or in the middle part of the vertical sequence of the floodplain alluvium. 14 samples of charcoal from the upper courses of the San (ca. 50 km) and the Strwi?? (ca. 10 km) were dated with radiocarbon. The obtained dates fall mainly in the 15^th through 19^th century interval; only one sample is markedly older (9^th–10^th century). Taxonomic composition of the charcoal source wood was also studied and compared with that of coeval forests. Correlation of the charcoal age with the history of economic development of the studied region indicates that charcoal is of anthropogenic origin: older charcoal from intense slash-and-burn deforestation, while younger charcoal was produced by local industries.     

Burning wood or burning bone? A reconsideration of flotation evidence from Upper Palaeolithic (Gravettian) sites in the Moravian Corridor

This paper compares archaeobotanical and other data from new excavations at two Upper Palaeolithic sites — Dolní V?stonice II and P?edmostí I — in the Moravian Corridor, Czech Republic. Both contain the traces of broadly contemporary ‘Gravettian’ occupations during the warmer episodes of the Pleistocene which preceded the last glacial maximum. Yet their archaeobotanical remains show striking differences — those from Dolní V?stonice II being dominated by large quantities of conifer wood charcoal, while those from P?edmostí I are much more scanty and dominated by vitrified plant remains, in association with large quantities of burnt bone. We argue that these differences between these two datasets arise from different uses of fuel at either site: bone at P?edmostí I and wood at Dolní V?stonice II. Subsequently, we explore the possible reasons for this difference and argue that once likely taphonomic distinctions are accounted for, these data on fuel use offer fresh insights into the functions and durations of these Upper Palaeolithic occupations of the Moravian corridor and some possible implications for how archaeobotanical data from such sites should be interpreted.     

Morphological,chemical and physical changes during charcoalification of wood and its relevance to archaeological contexts

Wood exposed to a heat source can be transformed into charcoal if subject to conditions of carbonisation (in the absence of air) or charring (in restricted air). Charcoal recovered from archaeological sites can yield fundamental information to our understanding of human economic and cultural development over time and (ecological) setting. This work describes the morphological (anatomy, degree of shrinkage), physical (reflectance) and chemical (elemental, molecular composition) properties of charcoal in relation to heat source and wood variables. In this study charcoal and charcoal fuel were experimentally produced whereby temperature (160–1200 °C), time of exposure (2–1440 min), heating rate (high and low) and wood type (angiosperm and conifer) were varied. The results show that charcoal, often described as an inert, black material, has different chemical and physical properties in relation to the investigated variables. By using these different properties it is possible to distinguish between the different types of fires (domestic and industrial) exploited by humans in the past. Morphological analyses and reflectance measurements are effective tools for this purpose and can be used in wood exposed to temperatures of 300 °C and above—temperatures which are relevant to archaeological research. Angiosperm and conifer wood react in different ways when exposed to heat and thus the taxonomic identity of archaeological material needs to be known. Chemical analyses can be used for wood exposed to temperatures below 400 °C whereas elemental analyses of the carbon content can be used for wood exposed to temperatures up to a maximum of 650 °C.     

Archaeological Identification of Stone Fish-weirs Mentioned to Freycinet in 1819 on the Island of Guam

ABSTRACT

In 1819, when the French corvette L'Uranie anchored off Apra Harbor in the Micronesian Island of Guam, its captain Louis Claude de Freycinet was told of the former use there of stone fish-weirs. This reference has long puzzled archaeologists and historians who assumed Freycinet was misinformed or such features were no longer in existence, given the frequent typhoons that affect the region. Recent archaeological surveys of Apra Harbor tidal flats, however, have identified low-walled coral enclosures at the mouth of two freshwater estuaries. At first. these were hypothesised to have been built to foster shellfish production under the Japanese occupation of Guam during World War II. However, controlled excavation of small sites adjacent to one of these complexes yielded late Latte Period pottery and wood charcoal radiocarbon dated to AD 1645–1725. This historic timeframe is within the plausible memory of the oldest generation of Freycinet's informants. These archaeological findings, combined with interviews, research of historical accounts and ethnographic comparisons of fishing practices in Micronesia and further afield suggest that Chamorro fishermen may have used the weirs to feed local populations and visiting sailors during the seasonal arrival of the Manila galleons for a long period after Ferdinand Magellan's visit in 1521. This conclusion has practical and contemporary implications for Chamorro today.     

The use of wood in funerary pyres: random gathering or special selection of species? Case study of three necropolises from Poland

In this study, the analysis of charcoal remains from three prehistoric necropolises is presented. This botanical material formed part of funerary pyres and thus represents purposely gathered wood used for cremation ceremonies. Therefore, its anthracological analysis may indicate a special selection of wood, which may be a source of palaeoethnographic information about past rituals. However, a question remains as to whether or not the charcoal assemblages that originated from graves may also provide some palaeoecological information. In order to test both hypotheses, analysis of three Polish necropolises dating to the Bronze and the Iron Age were performed. In all charcoal assemblages, a taxonomic diversity among charcoals was detected, which may suggest that the wood was collected based on availability. This may also be inferred after observing that the presence of the most ubiquitous and frequently found taxa may be strongly correlated with present-day vegetation growing in the vicinity of the necropolises.     

Seasoned or green? Radial cracks analysis as a method for identifying the use of green wood as fuel in archaeological charcoal

For several years, sociological questions have been central in anthracology. The development of socio-economic approaches based on the recognition of anatomical signatures in wood has made it possible to focus on topics related to firewood use and its management. The presence of radial cracks (RC) on archaeological charcoal is generally interpreted as the result of the burning of green wood. The present study proposes a verification of this theory by the experimental combustion of seasoned and green wood of Scots Pine (Pinus sylvestris L.). Experimenting with this species was a research priority since it was the dominant taxon (representing 80-100% of the charcoal remains) identified in the Palaeolithic European sites under consideration.The experiments were conducted using two different methods: (i) inside a muffle furnace that allowed us to control the combustions, but in which the combustion process is quite different from most archaeological situations and (ii) in an open fireplace, less controllable but closer to the archaeological conditions. The systematic quantification of the number, length and width of the radial cracks (RC) measured on the transversal sections of the experimental samples demonstrates that (i) radial cracks occur independently of the moisture content of the wood before the combustion (on green and seasoned wood); (ii) however, the average number of radial cracks (RC/cm²) allows distinguishing seasoned from green wood; (iii) in the muffle furnace, the size of the RC appeared to be a good criterion for discriminating seasoned and green wood, but this observation was not confirmed by the open-air combustions. Our results clearly show that the appearance of radial cracks is not diagnostic of the combustion of green wood. Nevertheless, the number of radial cracks (RC/cm²) could represent a new method that might help identifying the combustion of green wood in archaeological charcoal samples.     

Modeling wood acquisition strategies from archaeological charcoal remains

Archaeological charcoal remains are often used to reconstruct local woodland composition in the past, but rarely address how and why people may have selected specific woody taxa for particular purposes. Models from the field of human behavioral ecology predict that people forage for wood resources by taking into account the relative usefulness, abundance, and handling time related to procuring different wood types. Archaeological and ecological data from the site of Gordion, in Central Anatolia (modern Turkey), were used to test expectations associated with such models. Results suggest that inhabitants of Gordion used wood types for fuel in proportion to their local availability, but that they selected specific, more distant woods for construction. In most occupation periods pine was preferred for construction, perhaps because it produces long, straight timbers for roofing, despite the distance at which it grows from the site. This case study demonstrates that behavioral ecology modeling can help to distinguish between multiple wood acquisition strategies potentially used in the past and improve our understanding of wood use from archaeological charcoal remains.     

Timber exploitation during the 5th–3rd millennia BCE at Arslantepe (Malatya,Turkey): environmental constraints and cultural choices

A considerable amount of charcoal remains from the archaeological site of Arslantepe (Eastern Anatolia) has been analysed. The anthracological assemblage comes from seven archaeological periods, ranging from the Late Chalcolithic 1–2 (mid-5th millennium BCE) to the Early Bronze Age III (late 3rd millennium BCE). The woody taxa exploited by the local communities appeared to have only minor changes throughout the investigated periods. For the evaluation of wood use practices, charcoal was chronologically grouped according to depositional context. The categories of depositional context identified differentiate between the uses of wood for structural parts of buildings, object manufacture, fuel, refuse, and wood found in outdoor areas or in burial contexts. Communities at Arslantepe, characterized by different cultural and socio-economic traits, appeared overall to select timber depending on its use: hydrophilous plants prevail in building material, with the exception of the 2900–2500 BCE period when environmental constraints probably motivate the dominance of woodland-steppe plants. The differential occurrence of taxa in the diverse depositional contexts highlighted cases of under/overestimation of remains, in particular in relation to the woods for construction. Finally, taxa have been attributed to different ecological groups. The interpretation of results and the comparison with other available palaeoenvironmental data point out that climatic factors play only a secondary role in the choice of wood exploitation in the area. Human choice may vary even with constant environmental records.     

Quantifying woodland resource usage and selection from Neolithic to post Mediaeval times in the Irish Midlands

The antiquity and context (site or feature type) are the two principal factors that act as a framework for interpreting charcoal and wood data from archaeological sites in the recreation of past woodland environments. This research addresses these parameters through the analysis of over 18,000 charcoal fragments from 57 archaeological excavations carried out along a 61?km road scheme in the midland region of Ireland. Observations on spatial vegetation dynamics and woodland resource patterns are also reported on. The data were analysed through percentage frequency and multivariate analyses. The results reveal woodland resource usage in terms of wood types selected for use as fuel or as structural wood as well as patterns of change and variability in taxonomic composition in relation to site types, feature types and time periods. Selection was found to be low in prehistoric times and in particular at burnt mound sites/fulachta fiadh but became increasingly important as time progressed. This has important implications when charcoal from archaeological settings is used in environmental reconstructions.     

Sustainable management of metallurgical forest on Mont Lozère (France) during the Early Middle Ages

Mont Lozère, located in the French Massif Central region, provides an exceptional context in which to research the impact that charcoal production and metallurgy had on woodlands, along with the role that these activities played in changing the mountain landscape. This study provides an insight into the land use, forest management methods and metallurgical practices in the area during the Middle Ages (11th to 15th centuries). Medieval charcoal burning platforms, archaeological remains that have often been neglected in the past as a source of historical information, along with nearby smelting sites, were identified, sampled and analysed. In this paper, spatial analyses, radiocarbon dating and anthracological and dendro-anthracological studies have been combined in a unique manner. The results reveal that charcoal burners practiced beech coppicing, where the species and diameter of wood used remained the same over a period of four centuries. It is proposed that this form of metallurgical forest management be considered an early example of a sustainable utilisation of natural resources.     

THE ANCIENT MINE OF SERVETTE (SAINT‐MARCEL,VAL D’AOSTA,WESTERN ITALIAN ALPS): A MINERALOGICAL,METALLURGICAL AND CHARCOAL ANALYSIS OF FURNACE SLAGS*

The Cu–Fe mining district of Servette is located in the valley of Saint‐Marcel (Val d’Aosta) at about 1800 m a.s.l. in the western Italian Alps. A large furnace slag deposit occurs near the Servette mine. Slags are mainly constituted by silicate and oxide in a glassy matrix, with disseminated sulphides and iron–copper alloys, and they record temperatures of 1380–1100°C. Radiocarbon dating of slag charcoals has shown that metallurgy in this site took place around ad 890–980. The charcoal analysis has shown that coniferous wood was mainly utilized, and intensive exploitation over the centuries led to a change in the composition of the local woods.     

Analysis of Construction Timber in Rural Austria: Wooden Log Walls

House-building with wood has a long tradition in Austria. In this study, 47 houses from the Austrian Alps and the alpine foothills were analyzed. Dendrochronology was used to date the houses and to extract further information as construction phases within one building and time needed for harvesting. The construction dates range between 1452 and 1934. The focus was set on log constructions and in particular on wooden log walls. All wooden walls were made of softwood, clearly dominated by Norway spruce (Picea abies). A remarkable decline in the utilization of spruce wood as construction timber was found during the 19th century, which might be due to the high charcoal production at that time. By analyzing age, wood species, time of harvesting and way of processing, knowledge about wood utilization and historical forest management can be regained. Furthermore, some social and economical background of the farmers can be lifted. Technical dates as wall thickness and total wood volume required to build a residential building is provided.     

Book Reviews

Abstract

Plant macroremains were recovered during the renewed excavation at Grap?eva ?pilja, a cave on the island of Hvar in Croatia. This is the first archaeoboatnical investigation on an eastern Adriatic island to use flotation samples. Samples were taken from layers dating from the Early Neolithic to the Middle Bronze Age (ca. 6000–1500 B.C.). Sixteen radiocarbon dates obtained from wood charcoal date the samples precisely. Detailed archaeobotanical analyses of plant macroremains reveal plant use during the occupation of the cave, with the highest density of plant remains in the Neolithic. Oak acorns were the most abundant plant remains. Finds of two types of juniper berry cones, various parts of gymnosperm cones, and cypress seeds and leaves indicate that the Mediterranean evergreen woodland was exploited. Remains of cultivated plants are rare. A small number of cereal grains, including emmer, einkorn, and possibly bread wheat were recovered from the Neolithic layers, as well as a few wheat grains from later horizons. Remains of typical wild Mediterranean fruits included almond nutshell fragments, a grape pip, and a fig seed. These finds indicate that the occupants of Grap?eva utilized processed crops but also gathered plants from the wild for food, fuel, and perhaps ritual. Fourier Transform Infrared Spectroscopy (FTIR) analysis was performed in order to assess charred versus mineralized preservation. Macroplant remains from Grap?eva were compared to the few available plant analyses from the eastern Adriatic. This comparison provides evidence that caves had different functions both from each other and from open-air sites. The plant remains are discussed in the context of the spread of farming on both sides of the Adriatic.