Pyrogenic organic matter from palaeo-fires during the Holocene: A case study in a sequence of buried soils at the Central Ebro Basin (NE Spain) (original) (raw)
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Scientific Reports
Among the outstanding questions about the emergence of human-controlled fire is the systematic recurrence between the geochemical remains of fire and its preservation in the archaeological record, as the use of fire is considered a technological landmark, especially for its importance in food cooking, defensive strategies, and heating. Here we report fossil lipid biomarkers associated with incomplete combustion of organic matter at the Valdocarros II site, one of the largest European Acheulean sites in Spain dated to marine isotopic stage (MIS) 8/7 (~ 245 kya) allowing a multiproxy analysis of human-controlled fire use. Our results reveal isolated cases of highly concentrated and diverse polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs (APAHs), along with diagnostic conifer-derived triterpenoids in two hearth-like archaeological structures. The presence of combustion byproducts suggests the presence of anthropogenic (controlled) fires at Valdocarros—one of the oldest evide...
Journal of Archaeological Science: Reports, 2019
The Pago Lindo site in the River Plate basin (Uruguay) is an important pre-hispanic mound settlement (ca. 3000-600 B.P.), of which the technologically and socially advanced nature have only recently been revealed. Different angles of pedogenetic and palaeo-ecological science are rapidly improving our understanding of the history of the site and the relationships between human activity and habitat alteration. Here we add to this progress by molecular characterization of soil organic matter (SOM) in anthropogenic earthen mounds, canals and lagoons from Pago Lindo, by pyrolysis-GC-MS. The results showed that the SOM in the earthen mound and the archaeological lagoon are composed of microbial (partially chitin), aliphatic (partially root-derived) and pyrogenic (from fireplaces or wildfires) materials, whereas the canal and younger lagoon contained SOM with larger proportions of relatively intact plant remains (lignin and polysaccharides from herbaceous species). In most systems, a clear degradation trend can be observed with increasing depth-either from intact plant remains to microbial tissues (canal, young lagoon), or from microbial tissues to recalcitrant aliphatic and pyrogenic sources (earthen mound, ancient lagoon)-which is indicative of a strong control of decay intensity on SOM composition. Multivariate statistics confirmed that most variability in pyrolysis fingerprints can be attributed to degradation/preservation dynamics, which probably erased most of the molecular information on habitat development under the influence of past societies, including nearby maize cultivation.
History of fires and vegetation since the Neolithic in the Cantabrian Mountains (Spain)
Land Degradation & Development
Fire has been one of the main causes of disturbance of vegetation over time, and since the Neolithic has become an irreplaceable tool for the opening of forest spaces and maintenance of pastures. Previous studies showed that the intensity and effects of wildfires are related to the biomass and controlled by climate factors. However, in regions such as Cantabria, where agriculture and livestock have spread throughout the territory since prehistory, fires should also be closely related to human land uses. The aim of this paper was to investigate the history of fires and vegetation since the Neolithic in the Cantabrian Mountains, using sedimentary charcoals and pollen data to study the role of human activities in the processes that have shaped ecosystems throughout the Holocene. The asynchrony and quantitative differences in the results obtained at different sites indicate significant variations in fire patterns at regional scale since the Neolithic, although the type and size of each basin also had a strong influence on charcoal accumulation. Maximum values for charcoal accumulation rate (CHAR) at La Molina were observed between the Neolithic and the Bronze Age, but occurred after about 3500 cal years BP at El Cueto de la Avellanosa. At El Sertal, low CHAR values were observed, probably because the sequence begins in a space that already had been cleared; the maximum values occurred during the most recent millennium. These data provide evidence that fire has been a key factor in forest retreat and in maintaining open landscapes since the Neolithic.
Palaeogeography, …, 2011
The study of macroscopic charcoal particles from peat bogs has led to a better understanding of climate, vegetation and fire history, and human impacts. To determine the relationship between human activities and the role of fire events in vegetation change during the last 3300 cal yr BP, we present the results of a multiproxy approach based on the analysis of sediment characteristics, sedimentary charcoal, organic matter and pollen, as well as historical sources. This multi-proxy research permits high resolution palaeoenvironmental and fire history reconstruction of a mountain area located in the southern central Pyrenees (Spain). In the Pyrenees, fire is typically attributed to human activities since the beginning of the Bronze Age and may be correlated with slash-and-burn cultivation, metallurgy and pasturing activities. The data indicate a good linkage between high fire signals and Poaceae and Cerealia pollen, which reveals the impact of agro-pastoral practices. This study also shows two periods, 2900-2650 cal yr BP and 1850-1550 cal yr BP, for which higher frequencies of fire occurred, suggested by high arboreal pollen (AP) concentrations, and confirming the need for arboreal biomass to sustain fires. From the beginning of the Middle Ages, it seems that a change occurred in the anthropogenic use of fire, from a tool for agro-pastoral forest clearance to a means of maintaining open spaces.
Unravelling the precise Holocene altitudinal fluctuation of the highland vegetation communities (>1800 m asl) in the Gredos Range (Central System, Spain) is challenging owing to the complexity of the long-term human environmental interactions in the area. Aiming at improving the knowledge of these highland dynamics, a pedoanthracological analysis was conducted on six soil profiles located on the northern slope of the central sector of the Gredos Range, following an altitudinal transect between 2200 and 1700 m asl in the Las Pozas valley. The soil charcoal analysis revealed the long-term stability of the Leguminosae shrublands, which have dominated the landscape over 1800 m asl since the Early Holocene. The highest ancient timberline was sti-mated to be at approximately 1700 m asl in this valley, from the Early Holocene until the beginning of the Late Holocene. This ancient forest contained Pinus gr. sylvestris, with significant numbers of deciduous Quer-cus. However, scattered individuals or small groves of pioneer deciduous taxa (Betula sp., Populus sp., Salix sp., Maloideae and Prunus sp.) were found to have thrived over the timberline during the Early and Middle Holocene, especially between 1900 and 2000 m asl. The highest treeline was marked by Betula at 2100 m asl. Elevated values of charcoal concentration reflect the intense fire regime of the area. The pattern of fire events accumulation periods that can be inferred from the 23 dated charcoal samples is consistent with previous data, which supports an increase in fire frequency around 2000 cal yr BP, during the first reported period of significant human influence.
Palaeogeography, Palaeoclimatology, Palaeoecology, 300: 179-190 , 2011
Authors: Marie-Claude Bal, Albert Pelachs, Ramon Perez-Obiol, Ramon Julia, Raquel Cunill The study of macroscopic charcoal particles from peat bogs has led to a better understanding of climate, vegetation and fire history, and human impacts. To determine the relationship between human activities and the role of fire events in vegetation change during the last 3300 cal yr BP, we present the results of a multiproxy approach based on the analysis of sediment characteristics, sedimentary charcoal, organic matter and pollen, as well as historical sources. This multi-proxy research permits high resolution palaeoenvironmental and fire history reconstruction of a mountain area located in the southern central Pyrenees (Spain). In the Pyrenees, fire is typically attributed to human activities since the beginning of the Bronze Age and may be correlated with slash-and-burn cultivation, metallurgy and pasturing activities. The data indicate a good linkage between high fire signals and Poaceae and Cerealia pollen, which reveals the impact of agro-pastoral practices. This study also shows two periods, 2900–2650 cal yr BP and 1850–1550 cal yr BP, for which higher frequencies of fire occurred, suggested by high arboreal pollen (AP) concentrations, and confirming the need for arboreal biomass to sustain fires. From the beginning of the Middle Ages, it seems that a change occurred in the anthropogenic use of fire, from a tool for agro-pastoral forest clearance to a means of maintaining open spaces. Key words: Fire, Sedimentary charcoal, Pollen analysis, Organic matter, Historical sources, Human activities
Environmental Archaeology, 2017
Human control of fire is a widely debated issue in the field of Palaeolithic archaeology, since it involved significant technological innovations for human subsistence. Although fire evidence has been the subject of intense debate regarding its natural or anthropogenic nature, most authors agree that combustion structures represent the most direct evidence of human control of fire. Wood charcoal fragments from these contexts represent the fuel remains that result from humans' collection of firewood, which means they can reveal significant behavioural and palaeoenvironmental information relevant to our understanding of Middle Palaeolithic societies. In this work, we present anthracological data derived from combustion structure 2 (level XIII, ca. 230 ka, MIS 7) and combustion structure 4 (level XI, ca. 160 ka, MIS 6) from Bolomor Cave, which are chronologically among the earliest combustion structures found in Europe. The present work discusses how the presence of black pine and / or scots pine in both levels sheds light on the characterisation of the local landscape. Additional analyses focussing on the pre-and post-depositional processes affecting charcoal preservation point to biodegradation patterns. The aim of this work is to provide the first discussion concerning the anthracological data derived from Bolomor Cave in order to contribute to the general debate regarding the use of fire during the European Middle Pleistocene.