Evidence from charcoal analysis for environmental change during the interval late Bronze Age to Roman,at the archaeological site of Castro de Penices,N.W. Portugal

Vegetation and environmental change from late Bronze Age to the Roman period in north-west Portugal is reconstructed on the basis of charcoal analyses. The site was occupied by people of the Castrejo culture, i.e. an Iron Age culture that developed in the north-west Iberian peninsula. The pattern of exploitation of natural wood resources by local populations during this period appears to be similar during the three phases of occupation. The frequencies of light-demanding plant species, mostly Leguminosae, testify to considerable destruction and degeneration of the climax woodlands. The preference of particular wood for specific uses, such as roofing, is discussed and the Holocene history of selected trees within the wider region is considered.     

New insights into agriculture in northwestern France from the Bronze Age to the Late Iron Age: a weed ecological approach

Vegetation History and Archaeobotany - New plant macrofossil studies in northwestern France enable a better insight into agriculture through the Bronze and Iron Age. Most of the previous analyses,...     

Mortality changes in Central European populations from Bronze Age to Iron Age: Comparative analysis

The influence of cultural factors on the biological state, of prehistorical populations inhabiting Central Europe in the Bronze and Iron Ages have been analyzed. To achieve this goal the author studied changes in mortality structure of human groups said to belong to two various archeological cultures.     

Rapid change in host use of the common cuckoo Cuculus canorus linked to climate change

Parasites require synchrony with their hosts so if host timing changes with climate change, some parasites may decline and eventually go extinct. Residents and short-distance migrant hosts of the brood parasitic common cuckoo, Cuculus canorus, have advanced their phenology in response to climate change more than long-distance migrants, including the cuckoo itself. Because different parts of Europe show different degrees of climate change, we predicted that use of residents or short-distance migrants as hosts should have declined in areas with greater increase in spring temperature. Comparing relative frequency of parasitism of the two host categories in 23 European countries before and after 1990, when spring temperatures in many areas had started to increase, we found that relative parasitism of residents and short-distance migrants decreased. This change in host use was positively related to increase in spring temperature, consistent with the prediction that relative change in phenology for different migrant classes drives host-use patterns. These findings are consistent with the hypothesis that climate change affects the relative abundance of different host races of the common cuckoo.     

Interpretation of charcoal and pollen data relating to a late Iron Age ritual site in eastern Ireland: a holistic approach

The study of charcoal produced by five burning episodes that occurred in a rapid succession within a ritual pit dating to the late Iron Age at Raffin Fort, Co. Meath, Ireland, reveals considerable variation in the charcoal assemblages resulting from each burning episode. Wood selection processes are considered against the background of information on woodland composition and land-use history provided by a detailed pollen diagram from nearby Emlagh Bog, the chronology of which is based on both AMS ¹⁴C dates and tephra analysis. A human skull fragment lay on top of the charcoal layers but the radiocarbon evidence indicates that the skull predated the burnings by at least a century. This and other evidence indicate a ritual pit with the skull as a human relic. It is suggested that, in this instance, wood selection was neither random nor determined solely by availability or combustibility, but instead may have been informed by socio-religious belief systems pertaining to trees and wood. Early Irish documentary sources, which reveal a complex ethnography of wood and trees in later prehistoric and early historic Ireland, are reviewed. The results shed fresh light on aspects of late Iron Age archaeology in a part of Europe that was outside the direct influence of the Roman world. New information is provided on a distinctive feature in late Holocene Irish pollen records namely the Late Iron Age Lull (ca. a.d. 1–500). During this time, widespread regeneration of woody vegetation took place. In the subsequent early Medieval period renewed farming activity resulted in substantial decline in woodland, a pattern also seen at many other locations in Ireland.     

Land-use patterns and cultural change in the Middle to Late Bronze Age in Ireland: inferences from pollen records

In Ireland, the Middle to Late Bronze Age (1500–600 cal b.c.) is characterised by alternating phases of prolific metalwork production (the Bishopsland and Dowris Phases) and apparent recessions (the Roscommon Phase and the Late Bronze Age-Iron Age transition). In this paper, these changes in material culture are placed in a socio-economic context by examining contemporary settlement and land-use patterns reconstructed from the pollen record. The vegetation histories of six tephrochronologically linked sites are presented, which provide high-resolution and chronologically well-resolved insights into changes in landscape use over the Middle to Late Bronze Age. The records are compared with published pollen records in an attempt to discern if there are trends in woodland clearance and abandonment from which changes in settlement patterns can be inferred. The results suggest that prolific metalworking industries correlate chronologically with expansion of farming activity, which indicates that they were supported by a productive subsistence economy. Conversely, declines in metalwork production occur during periods when farming activity was generally less extensive and perhaps more centralised, and it is proposed that disparate socio-economic or political factors, rather than a collapse of the subsistence economy, lie behind the demise of metalworking industries.     

Cannabis in Eurasia: origin of human use and Bronze Age trans-continental connections

A systematic review of archaeological and palaeoenvironmental records of cannabis (fibres, pollen, achenes and imprints of achenes) reveals its complex history in Eurasia. A multiregional origin of human use of the plant is proposed, considering the more or less contemporaneous appearance of cannabis records in two distal parts (Europe and East Asia) of the continent. A marked increase in cannabis achene records from East Asia between ca. 5,000 and 4,000 cal bp might be associated with the establishment of a trans-Eurasian exchange/migration network through the steppe zone, influenced by the more intensive exploitation of cannabis achenes popular in Eastern Europe pastoralist communities. The role of the Hexi Corridor region as a hub for an East Asian spread of domesticated plants, animals and cultural elements originally from Southwest Asia and Europe is highlighted. More systematic, interdisciplinary and well-dated data, especially from South Russia and Central Asia, are necessary to address the unresolved issues in understanding the complex history of human cannabis utilisation.     

Dendrochronological analyses of wood samples from a Late Bronze to early Iron Age site at Lake Luokesa,Lithuania

Tree rings of 184 archaeological wood samples from two Late Bronze to early Iron Age lake sites at Lake Luokesa (Luokesai e?eras), Lithuania, Moletai district, were analyzed. Despite severe difficulties with synchronization, Pinus (pine), Quercus (oak) and Alnus (alder) yielded some cross-datable series. The general picture is that the settlers chose small trees as timber, which they used in their natural round shape. The trees did not grow in homogeneous even-aged stands, but show very different ages and growth levels. Despite the generally low numbers of tree rings in the individual samples, the strong archaeological framework allowed cross-dating of some series and the building of chronologies for single structures. Based on these attempts, a 90 year long first floating chronology of the settlement structures is presented. Luokesa Site 2 (L2) was mainly built within the relative year 53. Luokesa Site 1 (L1) was certainly in use from the relative year 74 onwards. All fences at L1 show their main building activity in the relative year 81, four years after the main building activities in the village itself. It can be concluded that the settlement L1 was in use for at least 16 years. Because of the lack of a standard dendrochronological curve for the Baltic region, wiggle-matching was applied to obtain an absolute date for both settlements. The data clearly show that all samples relate to the Late Bronze–early Iron Age. The period where all wiggle matching results overlap is the period between 625 and 535 bc (the 2σ ranges are given). Based on the dating, duration and timber characteristics of the occupation, comparisons with Polish early Iron Age sites are made, which indicate a close resemblance in terms of wood use and settlement concept.     

Early Holocene environmental change in the Kreekrak area (Zeeland, SW-Netherlands): A multi-proxy analysis

Detailed botanical (microfossil and macroremain), zoological and geochemical analyses (major and trace elements including C, Al, S, Ca, Fe, P, As, Zn, U, Ba and Rare Earth Elements) of organic deposits provide new insights into Early Holocene environmental change in the Kreekrak area (southwestern Netherlands). The age assessment of the record is based on high resolution AMS ¹⁴C wiggle-match dating (WMD). For the first time an AMS ¹⁴C WMD based chronology covering the Late Glacial/Holocene transition and early Preboreal is introduced for a site in The Netherlands.The Kreekrak botanical record reflects the end of the Younger Dryas to early Boreal and can be well correlated with pollen records from other sites in The Netherlands and Belgium. The palaeo-topography showed that the Kreekrak deposits formed in an abandoned channel of the River Schelde. Around ca. 11,490 cal BP, at the end of the Late Glacial/Holocene transition, infilling of the lake started with predominantly organic deposits in slowly running water. As a result of the warmer climate the area became forested with birch and poplar during the Friesland Phase (ca. 11,490-11,365 cal BP). Biological productivity of the lake and its surroundings increased. Aquatic vegetation developed in the lake, while shrubs of willow, reed swamps and grasslands fringed the shores. Precipitation increased, which caused a rise in the lake water table and an increase in the supply of oxic surface (= river) water into the Kreekrak lake. During this period, the Kreekrak lake was fed by inflowing river water, run-off, precipitation and seepage of Fe-rich groundwater. Around ca. 11,435 cal BP the water became stagnant probably as result of a total cut-off of the river channel. Inflow of river water ceased, while the supply of reduced Fe-rich groundwater became dominant. During the Rammelbeek Phase (ca. 11,365-11,250 cal BP), the climate was more continental and the abundance of grasslands and open herbaceous vegetation increased. Biological productivity remained high. In the lake, the supply of Fe-rich groundwater continued, the water level slightly decreased but aquatic vegetation remained present. At the end of the Rammelbeek Phase a sudden reduction in the supply of Fe-rich reduced groundwater caused a lowering of the groundwater level in the area, resulting in the development of a hiatus. Due to this hiatus, the Late Preboreal (11,250-10,710 cal BP) is absent from the record. During the early Boreal (10,710-10,000 cal BP) the landscape became densely forested and accumulation of peat in the former lake resumed due to a slowly rising groundwater level. The Boreal was a relatively stable period with low sedimentation rates.The combination of palaeobotanical and geochemical analyses in the Kreekrak record shows a close interrelation between landscape development and geochemistry. It appears that the environmental development of this area during the Late Glacial/Holocene transition and Early Holocene was largely influenced (directly or indirectly) by major climatic changes that occurred during this period, which determined local phenomena such as the composition and density of the vegetation, occurrence of seepage and river activity. Further research of this type has the potential to develop the application of major- and trace element geochemistry in palaeoenvironmental reconstructions.     

Rapid evolutionary change in a secondary sexual character linked to climatic change

The ability of organisms to respond evolutionarily to rapid climatic change is poorly known. Secondary sexual characters show the potential for rapid evolutionary change, as evidenced by strong divergence among species and high evolvability. Here we show that the length of the outermost tail feathers of males of the socially monogamous barn swallow Hirundo rustica, feathers that provide a mating advantage to males, has increased by more than 1 standard deviation during the period from 1984 to 2003. Barn swallows from the Danish population studied here migrate through the Iberian Peninsula to South Africa in fall, and return along the same route in spring. Environmental conditions on the spring staging grounds in Algeria, as indexed by the Normalized Difference Vegetation Index, predicted tail length and change in tail length across generations. However, conditions in the winter quarters and at the breeding grounds did not predict change in tail length. Environmental conditions in Algeria in spring showed a temporal deterioration during the study period, associated with a reduction in annual survival rate of male barn swallows. Phenotypic plasticity in tail length of males, estimated as the increase in tail length from the age of 1 to 2 years, decreased during the course of the study. Estimates of directional selection differentials for male tail length with respect to mating success, breeding date, fecundity, survival and total selection showed temporal variation, with the intensity of breeding date selection, survival selection and total selection declining during the study. Response to selection as estimated from the product of heritability and total selection was very similar to the observed temporal change in tail length. These findings provide evidence of rapid micro-evolutionary change in a secondary sexual character during a very short time period, which is associated with a rapid change in environmental conditions.     

Biodiversity changes in a shallow lake ecosystem: a multi-proxy palaeolimnological analysis

Biodiversity is a key measure of environmental quality in lake ecosystems. Lake biodiversity can be assessed using modern survey data, but typically these data only provide a ‘snap-shot’ measure and in most cases it is not possible to reconstruct temporal trends in biodiversity, so that human impacts can be detected. Palaeoecological techniques offer an alternative means of identifying changes in biodiversity over the period of historical records and far beyond, but there are problems associated with this approach. This is because only a select set of organisms leave a trace in the sediment record such that it is not usually possible to make reliable assessments of diversity changes within an entire taxonomic order (e.g. the algae). Moreover these organisms are typically from the lower levels of the trophic hierarchy (i.e. plants and insects). The problems of identifying changes in biodiversity from the palaeolimnological record are addressed with reference to Groby Pool, a shallow, eutrophic, medieval lake in the English Midlands, which has been subjected to eutrophication over the last 150 years. ²¹⁰Pb and ¹³⁷Cs-dated sediment cores have been used to estimate short-term alterations in the composition and diversity of three groups of indicators, representing different levels in the trophic cascade, namely diatoms, aquatic pollen and chironomids. By exploring relationships, both between these indicators and with archival macrophyte records, an assessment is made of eutrophication-related changes in overall habitat diversity at the ecosystem level. These data suggest that the lake has undergone considerable nutrient enrichment, resulting in the loss of a diverse, mesotrophic macrophyte flora from at least the turn of the century onwards and its replacement by a few highly competitive species tolerant of high nutrient concentrations. Reductions in macrophyte diversity seem to be reflected palaeoecologically by a decline in the diversity of fossil chironomid assemblages, related to the breakdown of particular host-plant relationships amongst the phytophagic species. However, diatom assemblages generally exhibit the opposite trend, which may be related to increases in macrophyte cover and increasing opportunities for the colonization of diverse epiphyte communities. The different fossil indicators have different limitations and merits, and for this reason a ‘multi-proxy’ approach is essential if meaningful inferences are to be made of changes in lake biodiversity using palaeoecological data.     

Urbanization within a Dynamic Environment: Modeling Bronze Age Communities in Upper Mesopotamia

Here agent-based models are employed to explore the behavior of small communities and their associated economic systems within an area of climatically marginal environment in northern Syria and Iraq. The examples, drawn from late prehistoric and Bronze Age societies that developed at the onset of urbanization, show how small communities might respond to various resource stresses and environmental fluctuations. The computer simulations demonstrate that some households gain resources at the expense of others and the community becomes more economically differentiated through time with some households benefiting at the expense of others. The approaches discussed demonstrate that complex societies were capable of a wide range of responses to stresses that could be absorbed or amplified via a number of social, economic, or demographic processes.     

Vegetation stability in the Southeastern Brazilian coastal area from 5500 to 1400 14C yr BP deduced from charcoal analysis

Charcoal analysis of six shell mounds showed that no major changes of the mainland vegetation ecosystem have taken place along the southeastern Brazilian coast (22 degrees 53'-22 degrees 57'S, 42 degrees 03'-42 degrees 33'W) from 5500 to 1400 14C yr BP. These shell mounds have been occupied by sedentary fisher-gatherer-hunters. Charcoal fragments retrieved from vertical profiles in the archaeological sites were examined; taxonomic determinations were based on a reference collection of charred woods and a program for computer-aided identification. Charcoal assemblages of all the studied sites present taxa from various restinga vegetation types, mangroves, xeromorphic coastal forest, and inland Atlantic Forest. The restinga ecosystem, characteristic of the Brazilian coast, is associated with sandy beach ridges; the restinga forest was much more abundant during the studied period than nowadays. The charcoal assemblages represent mainly the local vegetation; a regional reconstruction depends on the study of numerous sites. In the Cabo Frio region, open restinga taxa are more abundant in the Sambaqui do Forte, while forest elements are more important in the Sambaquis Salinas Peroano and Boca da Barra. The sites studied in the Arraial do Cabo (Sambaqui da Ponta da Cabe?a) and in the Saquarema regions (Sambaquis da Pontinha and da Beirada) show that open restinga formations were locally predominant. A comparison of multivariate analysis applied to both charcoal assemblages and to phytosociological data of the extant vegetation showed a good correspondence between the charcoal spectra and the present vegetation. The high taxonomic diversity of archaeological charcoal samples and numerous fragments showing traces of decay before charring suggests that aleatory gathering of dead wood constituted the main source of firewood for fisher-gatherer-hunters populations. Condalia sp. was probably selected for cultural reasons.The only significant fluctuations on the charcoal spectra relate to the mangrove vegetation. Two relatively humid episodes (recorded from ca. 5500 to 4900/4500 and from ca. 2300 to 2000 14C yr BP), intercalated by two episodes of increased dryness with increased lagoon salinity (from ca. 4900/4500 to 2300 and from ca. 2000 to 1400 14C yr BP) were recorded in the Cabo Frio region. The changes in mangrove vegetation cannot be attributed to sea-level variations, for the three regressive and the two transgressive episodes identified for the Brazilian coast during this period are not in phase with the development of mangroves. The stability of the mainland vegetation ecosystem is probably due to the edaphic character of the coastal environments, which makes coastal formations much more resistant to climatic variations and less sensitive to climatic change. We propose that this environmental stability was a decisive factor in the maintenance of the fisher-gatherer-hunter sociocultural system.     

Adsorption of allelopathic compounds by wood-derived charcoal: the role of wood porosity

In Swedish boreal forests, areas dominated by the dwarf shrub Empetrum hermaphroditum Hagerup are known for their poor regeneration of trees and one of the causes of this poor regeneration has been attributed to allelopathy (i.e. chemical interferences) by E. hermaphroditum. Fire-produced charcoal is suggested to play an important role in rejuvenating those ecosystems by adsorbing allelopathic compounds, such as phenols, released by E. hermaphroditum. In this study, we firstly investigated whether the adsorption capacity of charcoal of different plant species varies according to the wood anatomical structures of these, and secondly we tried to relate the adsorption capacity to wood anatomical structure. Charcoal was produced from eight boreal and one temperate woody plant species and the adsorption capacity of charcoal was tested by bioassays technique. Seed germination was used as a measurement of the ability of charcoal to adsorb allelochemicals. The charcoal porosity was estimated and the pore size distribution was then calculated in order to relate the wood anatomical features to the adsorption capacity. The results showed that the adsorption capacity of charcoal was significantly different between plant species and that deciduous trees had a significantly higher adsorption capacity than conifers and ericaceous species. The presence of macro-pores rather than a high porosity appears to be the most important for the adsorption capacity. These results suggest that fire-produced charcoal has different ability to adsorb phenols in boreal forest soil, and therefore may have differing effects on the germination of seeds of establishing tree seedlings.     

Living-floors and structures from the Lower Paleolithic to the Bronze Age in Italy

New researches have been performed on the analysis of some Italian dwelling structures dating from the Lower Paleolithic to Bronze Age. Different methods have been applied to each study according to the extensions of the areas explored. The following sites have been analyzed: Isernia La Pineta (Molise), Visogliano (Trieste) - Lower Paleolithic; Grotta del Cavallo (Lecce), Grotta Grande and Riparo del Molare (Salerno) - Middle Paleolithic; Grotta di Fumane (Verona), Riparo Tagliente (Verona), Grotta Continenza (Fucino L'Aquila), San Bartolomeo (Maiella Mountain, Abruzzo) - Upper Paleolithic; Mondeval de Sora (Belluno), Alpe Veglia (Verbania) and Grotta Edera (Aurisina, Trieste) -Mesolithic; Cala Giovanna Piano (Pianosa Island, Livorno), Contraguda (Perfugas, Sassari), Colle Santo Stefano (Fucino, L'Aquila), Catignano (Pescara), Settefonti (L'Aquila) - Neolithic; Castellaro Lagusello (Monzambano, Mantua) - Bronze Age.     

Living in wetlands in the southeastern Baltic region during the Late Bronze to early Iron Age: the archaeological context of the Luokesa lake settlements

The prehistoric lake settlement tradition is spread far beyond the region of the Alps, and it has been known for a long time that lake settlements are not a characteristic of one particular area. The present paper presents the results of the first comprehensive, interdisciplinary investigations of such types of sites in Lithuania, the two lake settlements at Lake Luokesa (Luokesai e?eras). They were excavated with underwater archaeology techniques between 2000 and 2011. They are Late Bronze to early Iron Age transition (LBA–EIA) in date and were probably built and inhabited during a short period between 625 and 535 cal bc. The excavated archaeological material contains a wealth of well-preserved wooden architectural details and other organic materials. Therefore, the importance and unique character of these sites is beyond question. This paper gives an overview of the history of research on lake settlements in northeastern Europe. In addition, the archaeological material of the LBA–EIA settlements at Lake Luokesa is evaluated in the context of the other lake settlements in the southeastern Baltic region. Existing hypotheses and interpretations of the origins, development and use of the lake settlements of this region are discussed. All the investigations which have been done, including archaeobotany, palynology, dendrochronology and geoarchaeology, provide data for a well-grounded interpretation and reconstruction of the Luokesa lake settlements.     

Fire and bones: Bronze Age III in the North-Eastern Iberian Peninsula

Between the third millennium BP and the fifth century AD, there are numerous necropolises that house urns in the Iberian Peninsula. One example is the "Pi de la Lliura" (Vidreres, Girona). However, there is a dearth of research concerning these structures. The "Pi de la Lliura" housed 43 structures, which contained a total of 47 vessels with human remains. Of these 43 structures, 22 were totally or partially excavated at the laboratory. The evidence from the fragments indicates cremation at a temperature of 650-700 degrees C. Part of the cremated corpse was then deposited in an urn. One of the most unique characteristics of the necropolis is the high frequency of individuals younger than 20 years old. The mortality of sub-adults is high in any prehistoric necropolis, but it is even higher in a cremation necropolis. "Pi de la Lliura" is a very small necropolis, where corpses were treated similarly over a short period.