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The Chaco Region is the third biogeographic and morpho-structural territory of South America after the Amazon and Cerrado savannahs. This region is one of the few areas in the world where the transition from the tropics to temperate zones does not consist of a desert but of semi-arid woodlands and savannahs. The modern biodiversity patterns of the region were severely affected by the climatic and environmental changes that occurred during the Quaternary. Remains of an extinct megamammal Neosclerocalyptus sp. (Upper Pleistocene) and charred fossil woods inside of sedimentary nodules, was recently discovered in Chaco Argentina. The aim of paper is the paleoenvironmental reconstruction of quaternary sedimentation in the western Chaco through the taxonomic identification of charred woods and siliceous microfossils analysis. Twenty-three charcoal fragments related to Anacardiaceae, Apocynaceae, Fabaceae, Rhamnaceae and Malvaceae were identified. The phytolith analysis showed that Poaceae elements were the most abundant compared to the other herbaceous and non-herbaceous elements, along with algae and sponge microfossils. Eco-anatomic features of the charcoals and the microfossil remains suggest that environment and climate conditions existed in the area during the Upper Pleistocene were similar to the current one. Finally, the results reveal the presence of natural wildfires during the Quaternary in the region. [ABSTRACT FROM AUTHOR]

Late Holocene histories of vegetation, human activity, and climate inland of the Nobi Plain, central Japan, were investigated using pollen, charcoal, and chronological (radiocarbon and pottery) analyses of the Arao-Minami archaeological sediment layers. This site was home to a large regional community from the Yayoi to Kofun periods. Agricultural production of buckwheat began before the Middle Yayoi (∼200 BC). Cultivated Poaceae increased in the warm period at ca. 2.2–1.7 cal ka BP (ca. 250 BC to ca. 250 AD), based on the pollen-based climate indices. This can be regarded as intensified wet rice agriculture occurring at this period because the archaeological examinations report the existence of paddy-field remains and rice phytoliths from the Late Yayoi to Early Kofun. This period approximately corresponds to the Roman Warm Period. Primary natural forests, such as Quercus subg. Lepidobalanus , Quercus subg. Cyclobalanopsis , Cupressaceae, and Cryptomeria , as well as cultivated Poaceae gradually decreased from ca. 1.7 to ca. 1.2 cal ka BP (ca. 250 AD to 750 AD), which corresponds to the Dark Age Cold Period. In contrast, an expansion of Pinus conifer forests and temporal rises of accumulation rates occurred in this period. Based on the evidences, we propose that the agriculture at this site temporarily changed to slash-and-burn cultivation at a nearby mountain, associated with the cold climate. In the warm period from ca. 1.2 cal ka BP (ca. 750 AD), cultivated Poaceae increased again, suggesting a return to wet rice agriculture around the site. In this paper, we conclude that ancient people who lived inland of the Nobi Plain adapted to global climate changes. [ABSTRACT FROM AUTHOR]

In recent years, archaeologists have studied how ancient humans have shaped, and been shaped by, their surrounding environments in an effort to provide valuable insight into the patterns of human-environment interaction during prehistoric and historical periods. Along the Heihe River in Hexi Corridor of northwest China, archaeologists have found many ancient cities that are good places to explore changes in human settlement patterns in relation to environment change in historical periods. In this paper, we present our investigation of seven ancient cities to clarify the chronology of these cities and their strategy for wood use in the area through the application of radiocarbon dating and charcoal identification. Our results suggest that the ages of many cities are younger than previous estimates, and humans mainly used Tamarix and mixed Tamarix and broad leaf trees in the lower and middle reaches of the Heihe River basin between ∼ AD 240–1380 respectively, and roughly matches the modern spatial distribution of natural woody vegetation in the area. In comparison to the results of archaeological, paleoclimatic and historical studies in Hexi Corridor, we propose that ancient human strategies for wood use and their impact on environment of the Heihe Basin are primarily relevant to human lifestyles rather than climate change. [ABSTRACT FROM AUTHOR]

Changes in subsistence patterns during the Upper Paleolithic and Mesolithic at Klissoura Cave 1 in southern Greece indicate that some shifts track local climatic changes, while others do not. Specifically, increases in ungulate species diversity correlate with wetter periods, and greater abundance of certain dry-loving small game animals (e.g., great bustard) might correspond with dry periods. Other large-scale diachronic shifts, such as the increased importance of low-return hares and partridges, occur over the occupation of the site irrespective of environmental conditions. We hypothesized previously that this relates to local human population growth over the course of the Paleolithic. New data from a nearby site, Kephalari Cave, augment this hypothesis. The site complements the Aurignacian and Gravettoid occupations at Klissoura and also contains a robust late Upper Paleolithic component. Ungulate species diversity is high at Kephalari, and there is a greater reliance on low-return small animals (including fish) than at Klissoura. In this paper, we examine changes in the faunal spectra alongside preliminary charcoal data from the two sites. These data are analyzed in the context of regional environmental change in order to determine the extent to which climatic change or population growth drove subsistence shifts in southern Greece during the Late Pleistocene. [ABSTRACT FROM AUTHOR]

The Changbaishan volcano, located in northeast China, produced a large amount of charcoal during the "Millennium Eruption" (c. 946 CE). In this paper, we report a high-resolution date for the eruption using multiple methods applied to the fossil charcoal and living trees, including wood anatomy, radiocarbon dating and tree-ring cross-dating. In addition, we develop a new floating annual-resolution tree-ring chronology spanning nearly 200 years that provides information about paleoclimate conditions. In our study, we identified 60 samples of charcoal as Larix olgensis based on anatomical characteristics and geographical location. Using these materials, we dated the eruption to the winter of 946 CE based on a combination of radiocarbon dating, traditional dendrochronological cross-dating and cambial cell growth status. This allowed us to develop an L. olgensis tree-ring width chronology covering 764–946 CE and 1715–2016 CE, with significant sensitivities to April–September temperature (p < 0.05). The tree-ring data have great potential to indicate extreme climate events; for example, we identify an extremely cold year in 903 CE. Such marker years can improve the reliability and accuracy of tree-ring data. Our study provides direct and precise tree-ring evidence for volcanic eruptions and anomalous climate years in the Middle Ages. [Display omitted] • Cambial activity enables us to date the Millennium Eruption to winter 946 CE. • The first chronology reaching the Middle Ages so far developed in northeastern China. • The chronology was assembled from volcanic charcoal and living larch. • This chronology is sensitive to temperature. [ABSTRACT FROM AUTHOR]

Abstract: Carbon sequestration is the process of capture and long-term storage of atmospheric carbon dioxide ( ) with the aim to avoid dangerous climate change. In this paper, we propose a simple mathematical model (a coupled system of nonlinear ODEs) to capture some of the dynamical effects produced by adding charcoal to fertile soils. The main goal is to understand to which extent charcoal is able to lock up carbon in soils. Our results are preliminary in the sense that we do not solve the sequestration problem. Instead, we do set up a flexible modeling framework in which the interaction between charcoal and soil can be tackled by means of mathematical tools. We show that our model is well-posed and has interesting large-time behaviour. Depending on the reference parameter range (e.g., type of soil) and chosen time scale, numerical simulations suggest that adding charcoal typically postpones the release of . [Copyright &y& Elsevier]

Abstract: Precisely how Upper Palaeolithic human ecology was shaped by changing climate during the Pleniglacial remains a matter of debate, for while this generally cold period is now understood to include complex and often rapid flux in climate, there are still considerable difficulties in resolving climatic variations at particular times and places — derived from various lines of proxy evidence — with the high-resolution proxy record of temperature changes from oxygen isotope analysis of the Greenland ice-cores. In this paper we apply the methodology of large-scale flotation to newly excavated contexts from the Upper Palaeolithic (Gravettian) site of Dolní Vĕstonice II, Czech Republic, to explore the potential of charcoal — as a natural archive of environmental information — to offer information on environmental change towards the end of the middle pleniglacial during Oxygen Isotope Stage 3, between c. 32,500 and 31,200 Cal yr BP. The results of an analysis of ring widths and other anatomical features — interpreted alongside micromorphological data — indicate that this charcoal may capture a higher-resolution record of the changing climatic conditions during which humans were first expanding into these hitherto marginal ecologies and, consequently, shed new light upon the complexity of the lifeways that enabled them to do so. [Copyright &y& Elsevier]

Abstract: High-resolution macroscopic charcoal and pollen analyses were used to reconstruct the fire and vegetation history of the Willamette Valley for the last 1200years. Presented in this paper are three new paleoecological reconstructions from Lake Oswego, Porter Lake, and Warner Lake, Oregon, and portions of previous reconstructions from Battle Ground Lake, Washington, and Beaver Lake, Oregon. The reconstructions show that prior to Euro-American settlement vegetation and fire regimes were influenced by a combination of natural and anthropogenic factors. Battle Ground Lake shows a stronger influence from climate, while Lake Oswego, Beaver Lake, Porter Lake, and Warner Lake were more controlled by human activity. However, human-set fires were also modulated by regional climate variability during the Medieval Climate Anomaly and the Little Ice Age. Fire reconstructions from Battle Ground Lake, Lake Oswego, Beaver Lake, and Porter Lake imply that fires were infrequent in the Willamette Valley 200–300years prior to Euro-American settlement. The decline of Native American populations due to introduced disease may have led to this reduction in fire activity. The prehistoric record from Warner Lake, however, indicates that fires in the foothills of the Cascade Range were more frequent than on the valley floor, at least until ca. AD 1800. The historic portions of the reconstructions indicate that Euro-American land clearance for agriculture and logging produced the most dramatic shifts in vegetation and fire regimes. All five records indicate that few fires in the Willamette Valley have occurred since ca. AD 1930, and fires today are predominantly grass fires. [ABSTRACT FROM AUTHOR]

Abstract: This paper addresses the quantification of combustion-derived products in oceanic and continental sediments by optical and chemical approaches, and the interest of combining such methods for reconstructing past biomass burning activity and the pyrogenic carbon cycle. In such context, the dark particles >0.2µm2 remaining after the partial digestion of organic matter are optically counted by automated image analysis and defined as charcoal, while the elemental carbon remaining after thermal and chemical oxidative treatments is quantified as black carbon (BC). The obtained pyrogenic carbon records from three sediment core-based case studies, (i) the Late Pleistocene equatorial Pacific Ocean, (ii) the mid-Holocene European Lake Lucerne, and (iii) the Late Holocene African Lake Masoko, are interpreted as proxy records of regional transportation mechanisms and biomass burning activities. The results show that the burial of dark carbon-rich particles in the 360kyr-long record from the west equatorial Pacific is controlled by the combination of sea-level changes and low-latitude atmospheric circulation patterns (summer monsoon dynamics). However, the three fold increases in charcoal and BC sediment influxes between 53–43 and 12–10kyr BP suggest that major shifts in fire activity occur synchronously with human colonization in the Indo/Pacific region. The coarse charcoal distribution from a 7.2kyr record from Lake Lucerne in Switzerland closely matches the regional timing of major technical, land-use, and socio-economic changes during the Neolithic (between ca. 5.7 and 5.2kyr BP and 4.9–4.5kyr BP), the Bronze and Iron Ages (at ca. 3.3 and 2.4kyr BP, respectively), and the industrialization (after AD 1838), pointing to the key impact of human activities on the sources, transportation processes and reservoirs of refractory carbon during the Holocene. In the tropical Masoko maar lake in Tanzania, where charcoal and BC records are highly sensitive to the local climate and environment, surface runoffs from forested areas and/or aerial transportation over short distances are also important sources for detrital charred particles. However, this 4.3kyr-long record exhibits a major increase in charcoal and BC sediment influxes between 1.8 and 0.6kyr BP, synchronously with the regional extent of Late Iron Age and agricultural innovations. Therefore, in both marine and terrestrial depositional environments, the climate- and vegetation-controlled fire regimes appear to be strongly associated to societal changes, or directly affected by human practices. In fact, the anthropogenic effect associated to past human activities (e.g. settlement, agriculture, and metallurgy) has temporarily at least tripled the emissions of pyrogenic carbon in the environment. However, the data from the three Late Pleistocene to Holocene sequences also show that the redistribution of fossil particles by runoff and erosion processes is a significant source of pyrogenic carbon that should be understood as a prerequisite for interpreting sedimentary records of biomass burning. [Copyright &y& Elsevier]

Abstract: Current carbon accounting methodologies do not accommodate activities that involve emissions reductions from both land-use change and energy production. This paper analyzes the climate change mitigation potential of charcoal production in East Africa by examining the impact of changing both land management and technology. Current production in a major charcoal producing region of Kenya where charcoal is made as a by-product of land clearance for commercial grain production is modeled as the “business-as-usual” scenario. Alternative production systems are proposed based on coppice management of native or exotic trees. Improved kilns are also considered. Changes in aboveground, belowground, and soil carbon are modeled and two distinct baseline assessments are analyzed: one is based on a fixed area of land and one is based on the quantity of non-renewable fuel that is displaced by project activities. The magnitude of carbon emissions reductions varies depending on land management as well as the choice of carbonization technology. However, these variations are smaller than the variations arising from the choice of baseline methodology. The fixed-land baseline yields annualized carbon emission reductions equivalent to 0.5–2.8tons per year (ty−1) with no change in production technology and 0.7–3.5ty−1 with improved kilns. In contrast, the baseline defined by the quantity of displaced non-renewable fuel is 2–6 times larger, yielding carbon emissions reductions of 1.4–12.9ty−1 with no change in production technology and 3.2–20.4ty−1 with improved kilns. The results demonstrate the choice of baseline, often a political rather than scientific decision, is critical in assessing carbon emissions reductions. [Copyright &y& Elsevier]

Disentangling fire and its controls over thousands of years ago is a major challenge in the study of paleofires. In this paper, we synthesize sedimentary charcoal and black carbon from the coastal plain of Laizhou Bay, China to improve our ability to reconstruct fire history in the past 5000 years, and to assess the controls of fire using principal component analysis and multiple regression approach. The results show that there were three distinct fire episodes at the intervals of 5300–5100 yr BP., 1190–1060 yr BP., and 300–0 yr BP., based on the Changyi (CY) profile. A large-scale fire episode was synchronous with a rapid climate variability that occurred 5300 yr BP., which had frequent drought and cold epoch. High fluxes of black carbon and charcoal were closely related to mass migration and the use of fire for land reclamation from 1190 to 1060 yr BP. Subsequently, anthropogenic biomass burning for cereal cultivation has reached a higher level over the past 300 years. However, between 4600 and 4000 yr BP. the shifts in the frequency of high-magnitude floods and climate aridity consequently resulted in the decline of fire-episode frequency and the abandonment of the late Neolithic settlements in the study region. Therefore, climate is still a prerequisite factor for fire occurrence on the southern coast of Laizhou Bay in the past 5000 years. A rapid climate variability was not only responsible for various fire patterns, but also could affect human settlements and the mode of production during middle-late Holocene. In the past 1000 years, human land use has been a more important control of fire. However, temperature has become one of the evidently identified controls of fire across the study area in recent decades. To synthesize the methods of Principal Component Analysis and Multiple Regression Analysis with multi-proxy evidence is necessary for us to better understand fire and its controls on coastal plain of Laizhou Bay at the region. • Charcoal and BC have recorded fire mid-Holocene at the Laizhou Bay of China. • Climate was still a prerequisite control of fire at the Laizhou Bay mid-Holocene. • In the past 1000 years, human land use has been an important control of fire. • Temperature has become one of the identified controls of fire across the study area. • Principal component analysis will contribute to disentangling fire and its controls. [ABSTRACT FROM AUTHOR]

Reducing the vulnerability of agriculture to climate change while increasing primary productivity requires mitigation and adaptation activities to generate profitable co-benefits to farms. The conversion of woody-wastes by pyrolysis to produce bio-char (biologically derived charcoal) is one potential option that can enhance natural rates of carbon sequestration in soils, reduce farm waste, and substitute renewable energy sources for fossil-derived fuel inputs. Bio-char has the potential to increase conventional agricultural productivity and enhance the ability of farmers to participate in carbon markets beyond traditional approach by directly applying carbon into soil. This paper provides an overview of the pyrolysis process and products and quantifies the amount of renewable energy generation and net carbon sequestration possible when using farm bio-waste to produce bio-char as a primary product. While this research provides approximate bio-char and energy production yields, costs, uses and risks, there is a need for additional research on the value of bio-char in conventional crop yields and adaptation and mitigation options. [Copyright &y& Elsevier]

This paper attempts to reconstruct vegetation changes and to infer climate changes during the late Pleistocene and the Holocene in the southeast (Botucatu, Anhembi and Jaguariúna, São Paulo State) and centerwest of Brazil (Pontes e Lacerda, Mato Grosso State). The research approach included the use of carbon isotopes (13C and 14C) in soil organic matter (SOM) and the evaluation of charcoal distribution and its identification at the species level. Soils sampled in this study were located under natural vegetation, along the slopes of small hills. Charcoal was found predominantly between 150 and 50-cm depth, indicating a period of greater frequency of fires in the study areas, between 6000 and 3000 years BP. For the Botucatu, Anhembi and Pontes e Lacerda sites, the δ13C profiles suggest the predominance of C3 plants during the entire Holocene. The 13C patterns obtained at the Jaguariúna site that show a more significant presence of C4 plants compared to the other regions, suggest that this region has been drier than the others during the Holocene. These patterns also indicate the presence of a drier climate compared with present-day conditions at the Jaguariúna region during late Pleistocene until the middle Holocene. This study shows the complexity of vegetation dynamics in the southeast of Brazil during the Holocene. It also shows that the analyses of multiple soil cores representative of the main vegetation communities are necessary for paleovegetation studies. [Copyright &y& Elsevier]

The Tarvagatai Nuruu National Park, situated in the northern Khangai Mountains in central Mongolia, is dominated by a forest-steppe ecosystem. An extreme continental and semi-arid climate is characteristic for forest-steppe ecosystems in Central Asia and their vegetation is very sensitive to climatic changes and human impacts by pastoralism and tree-logging. In the selected study area, nowadays human impact is exceptionally low, and it has potentially also been in the past. The focus of this paper was to reconstruct vegetation variability, climate dynamics, intensity of human impact and fire dynamics by applying a broad multi-proxy approach on a lacustrine sediment core from a small closed lake in the study area. The analyses include reconstructions of pollen, spores, non-pollen palynomorphs, and charcoal distribution as well as XRF-scanning. Overall, the radiocarbon-dated lacustrine sediment core reveals stable, long-term environmental conditions since the early Holocene (9570 cal yr BP). Palynological results indicate that vegetation varies on a comparably low level. We assume that nomadic pastoralism played a tangential role on the vegetation changes in the study area. Higher values of coprophilous fungi between 9570 and 8350 cal yr BP suggest the highest wildlife activity during the early Holocene. Hence, our multi-proxy data reveal a surprisingly stable vegetation composition and only slight climatic changes in north-central Mongolia for the entire Holocene. An initial moist and warm period from 9570 to 4180 cal yr BP was followed by a period of slightly drier and potentially cooler conditions from 4180 until 430 cal yr BP. The latest period from 430 cal yr BP to present was moist and warm. Fires were in general relatively rare except from a strong phase of fire activity between 3550 and 2960 cal yr BP. • A new multi-proxy record (pollen, NPPs, macro charcoal, XRF-data) from north-central Mongolia. • Detailed high-resolution Holocene palaeoecological record covering the last 9600 cal yr BP. • Reconstructed stable vegetation reflects limited human impact on the vegetation dynamics since the Early Holocene. • Values of coprophilous fungal spores during the early Holocene provide a baseline of wildlife activities. • Extensive fire episode from 3550 to 2960 cal yr BP. [ABSTRACT FROM AUTHOR]