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Fundamental understanding of paleoecological proxies is necessary when attempting to compare, complement, or contrast two or more methods, and lack thereof may lead to erroneous conclusions. This comment addresses three such misunderstandings found in a recently published paper by Paillard et al. regarding soil macrofossil charcoal analysis (SMCA) and its relationship to lacustrine sediment analysis. The aim is to correct some misinformation associated with the following three assertions: (1) Broadleaved tree species produce fewer charcoal fragments than coniferous species. Although coniferous stands are more fire-prone, experimental burning shows that species with denser wood, that is, broadleaves, produce greater amounts of charcoal under similar fire conditions. (2) Preservation of charcoal particles is poor at the referenced study site. Once buried in the mineral soil compartment, charcoal particles remain quite stable. As such, SMCA has revealed Late Pleistocene marginal stands of broadleaved species. (3) Underestimating the importance of range-edge dynamics on the results of SMCA reconstructions. SMCA offers a stand-scale historical reconstruction that has proven well-suited to study peripheral stands and to reflect the heterogeneity of a landscape mosaic. By attempting to reconcile the SMCA (in situ) and lake sediments (ex situ) narratives, Paillard et al. missed one key aspect of comparing complementary proxies: they show different aspects of the past. [ABSTRACT FROM AUTHOR]

The nature and extent of past indigenous transformations in the Amazon basin is an actively debated topic, and one that has important implications for both conservation policy and the cultural heritage of its indigenous and traditional populations. The use of charcoal and phytoliths to measure past human impacts in non-lacustrine settings has become especially influential in this debate but has also generated disagreement among scholars regarding the possible limits of these proxies for detecting ancient land-use. To contribute empirical data to this issue, our paper presents the first attempt to study charcoal and phytolith signals from areas of modern indigenous land-use, in the Xingu Indigenous Territory, southern Amazonia. Our findings show that, while charcoal and early successional herb phytoliths are good indicators of land-use intensity, certain types of land-use leave subtler traces in the phytolith record that can hinder their detection. We demonstrate how using finer sampling resolution and comparing local proxy data on their own terms are necessary steps in order to identify trends in human land-use across time and space. [ABSTRACT FROM AUTHOR]

Charcoal from archaeological contexts differs from off-site pollen samples as it is mainly a product of intentional human action. As such, analysis of charcoal from excavations is a valuable addition to studies of past vegetation and the interaction between humans and the environment. In this paper, we use a dataset consisting of 6186 dated tree species samples from 1239 archaeological sites as a proxy to explore parts of the Holocene forest development and human-vegetation dynamics in South-Eastern Norway. From the middle of the Late Neolithic (from c. 2000 BC) throughout the Early Iron Age (to c. AD 550) the region's agriculture is characterized by fields, pastures and fallow. Based on our data, we argue that these practices, combined with forest management, clearly altered the natural distribution of trees and favoured some species of broadleaved trees. The past distribution of hazel (Corylus avellana) is an example of human impact on the vegetation. Today, hazel is not even among the 15 most common tree species, while it is one of the most prevalent species in the archaeological record before AD 550. The data indicate that this species was favoured already by the region's Mesolithic hunter-fisher-gatherers, and that it was among the species that thrived extremely well in the early farming landscape. Secondly, our analysis also indicates that spruce (Picea abies) first formed large stands in the south-eastern parts of Norway c. 500 BC, centuries earlier than previously assumed. It is argued that this event, and a further westward expansion of spruce, was partly a consequence of a specific historical event – the first millennium BC farming expansion. [ABSTRACT FROM AUTHOR]

Fire has a long history in Australia and is a key driver of vegetation dynamics in the tropical savanna ecosystems that cover one quarter of the country. Fire reconstructions are required to understand ecosystem dynamics over the long term but these data are lacking for the extensive savannas of northern Australia. This paper presents a multiproxy palaeofire record for Marura sinkhole in eastern Arnhem Land, Northern Territory, Australia. The record is constructed by combining optical methods (counts and morphology of macroscopic and microscopic charcoal particles) and chemical methods (quantification of abundance and stable isotope composition of pyrogenic carbon by hydrogen pyrolysis). This novel combination of measurements enables the generation of a record of relative fire intensity to investigate the interplay between natural and anthropogenic influences. The Marura palaeofire record comprises three main phases: 4600–2800 cal BP, 2800–900 cal BP and 900 cal BP to present. Highest fire incidence occurs at ~4600–4000 cal BP, coinciding with regional records of high effective precipitation, and all fire proxies decline from that time to the present. 2800–900 cal BP is characterised by variable fire intensities and aligns with archaeological evidence of occupation at nearby Blue Mud Bay. All fire proxies decline significantly after 900 cal BP. The combination of charcoal and pyrogenic carbon measures is a promising proxy for relative fire intensity in sedimentary records and a useful tool for investigating potential anthropogenic fire regimes. [ABSTRACT FROM AUTHOR]

Peatlands store massive amounts of organic carbon, but the fate of this carbon remains unclear as global climate continues to warm. The age of peatland inception and the main drivers of peat initiation are one of the most important issues in Holocene paleoecology, especially for the numerous but under investigated peatlands in European Russia. This paper introduces new peatland initiation ages for 44 mires in three areas located in the central part of European Russia within the Polesie landscape belt. This region is characterised by waterlogged sandy plains and flat surface topography. Phases of peatland initiation were compared with Holocene fire regime derived from macro-charcoal data as well as with regional climatic reconstructions. We found that peat inception in the region started around 12,000 cal yr BP, but the most active phases of peatland initiation took place during the periods 8500–7500, 7000–6000, 5300–5800, 4000–3500 and 1700–1200 cal yr BP. Expect for rapid peat growth during the early Holocene, peatland initiation mostly coincided with warm climatic periods and increased fire frequency. Forest soil paludification in poorly drained Polesie landscapes was presumably enhanced by reduced evapotranspiration and changes in water balance due to disturbance of forest cover after wildfires. We expect that rising air temperature in the current century will cause higher fire frequencies and may encourage waterlogging of forests and ecosystem transformation. [ABSTRACT FROM AUTHOR]

This paper presents the results of multiproxy research (pollen, charcoal, plant macrofossil and testate amoebae) on the biogenic deposits core from Gorodetsky Moch, an ombrotrophic peatland in western Russia (Western Dvina Lakeland). We reconstructed the impact of disturbance on peatland development in the last 300 years by using chronology of the records based on 14C and 210Pb data set. The multiproxy reconstruction was compared with changes in the land cover using historical maps and Corona images, which provides a unique spatial analysis of past ecological and land-use changes. We aimed to determine the effect of local disturbances (drainage) and land-use changes (landscape openness) on the development of the peatland during the last 300 years. Our study suggests that human activity had a crucial impact on the development of the peatland in the last centuries. The analysis of testate amoebae and plant macrofossils revealed a clear disturbed layer in the second half of the 20th century CE. Most probably, the drainage of the peatland triggered changes in the community of testate amoebae and plants, thereby causing a functional shift in Sphagnum peatland ecosystem. The hydrological stress and vegetation composition shift led to the collapse of mixotrophic testate amoebae. However, the peatland showed strong resilience and recovered toward the end of the 20th century CE and the beginning of the 21st century CE, despite the lower water table. Our study shows an example of the peatland ecosystem that experienced a considerable stress but finally sustained the former function. [ABSTRACT FROM AUTHOR]

Macroscopic charcoal records from wetland sediment cores are used to reconstruct long-term records of fire frequency. A central premise for the use of this tool is that macroscopic charcoal (>125 μm) represents local fires involving local vegetation. Several records reveal that there may often be exceptions to these guidelines. Previous studies have shown that particles larger than 1 cm long can travel at least 20 km from the location of a fire. We present observations of unprecedented long-distance transport of large (⩽5 cm long) charcoal particles at least 50 km from a fire west of Sydney, Australia. Factors that contribute to long-distance transport of large charcoal particles are fire intensity, upper level wind speed and landscape topography. The fires west of Sydney were large and intense, upper level (~10 km) winds exceeded 90 km h-1, and the topography east of the fire was flat or undulating. Smoke plumes from intense fires like this can reach an altitude of at least 15 km. Charcoal morphology also contributed to long-distance transport in this case. Eucalyptus trees can produce large quantities of aerodynamically efficient particles; from paper thin, smooth, decorticating bark and large sclerophyllous leaves. The presence of large macroscopic charcoal particles in wetland sediments does not automatically indicate local fires and could result from distant, large, intense fires. Large, intense fires can occur in Australia, the grasslands of Kazakhstan, Namibia, the Sahel and Patagonia. High intensity fires also occur in the forested areas of the western United States and Boreal North America. Fires in these regions could result in long-distance transport of large macroscopic charcoal particles under the right circumstances. Local charcoal flux studies are therefore critical for the interpretation of macroscopic charcoal records. We cannot rely on information from areas with different fire regimes, fire intensities or vegetation types. [ABSTRACT FROM AUTHOR]

This paper presents the first pedoanthracological study carried out on two mountains of the Northern Apennines, Monte Cimone, and Corno alle Scale, where the results provided new palaeoenvironmental data. The pedoantracological sampling followed an elevation gradient from the current timberline to the highest possible elevation, also adapted to the geomorphological characteristics of the study areas. Based on radiocarbon datings (16 at Monte Cimone and 9 at Corno alle Scale), the soil charcoal fragments provided data about the vegetation dynamics and plant landscape reconstruction, primarily indicating the Late Holocene. The landscape over the last 3000 years appears very similar to the current one with very small altitudinal variations of the timberline and treeline. The present study shows a lack of radiocarbon dates for the Middle Holocene and two hypotheses are discussed to explain this finding. Data suggest that past fires were locally linked to periods of climate optimum and possibly with the management of natural resources (especially animal grazing) by human societies. Some questions concerning the absence of Abies alba, today only present as plantation and normally associated with Fagus sylvatica at these latitudes, are discussed. [ABSTRACT FROM AUTHOR]

Terms referring to charcoal particle size classifications are inconsistent in the paleofire literature. Inconsistencies of terminology prevent effective scientific discourse and research comparability. In this paper, I use the Global Charcoal Database (GCD) to determine the relative usage of sieving size boundaries and use these metadata as a proxy for the consensus of the paleofire community. With consideration of the size classification bounds used in other fields, I propose a standardized size classification system and terminology for charcoal particles. This system consists of macroscopic (>125 μm), mesoscopic (50–125 μm), and microscopic (10–50 μm) charcoal particles and aims to unify paleofire jargon by conforming to the terminology and most commonly used size bounds in the community. [ABSTRACT FROM AUTHOR]

Cliff-top dunes are a locally important geomorphic features of sedimentary coasts. They are traditionally interpreted as being sourced by (or with) sand derived from the beach below the cliff. This paper presents the results of a stratigraphic and geochronological study of Carlo Sand Blow, a coastal blowout that has developed on top of a high sandy cliff in the Cooloola Sand Mass, south-east Queensland. We use a combination of sedimentological, pedological and geophysical techniques along with optically stimulated luminescence dating to determine the depositional history and evolution of the blowout. We demonstrate that the blowout is dominantly nourished by sand eroded from its floor rather than the adjacent beach. The original dune surface dates to the first half of the last glacial period (c. 40–70 ka) and this dune was deflated in the late-Holocene. Dune activity is directly associated with cliff undercutting because of coastal retreat in the late-Holocene, but coastal erosion on its own is not capable of maintaining aeolian activity. Blowout activity occurred between 2.6 and 2.3 ka and again at 0.3 ka with aeolian sand burying palaeosols. Both soil surfaces contained charcoal and tree stumps in growth position and our study suggests that fire is the immediate trigger for blowout reactivation. It is likely that these fires were anthropogenic in origin, because the site is somewhat protected from natural fire and the ages coincide with intensification of human use of coastal sites in the area. [ABSTRACT FROM AUTHOR]

In this paper, we present high-resolution early Holocene pollen, plant macrofossil, charcoal, diatom, biogenic silica, and loss-on-ignition records from a mountain lake in the South Carpathians in order to reveal ecosystem response to the 8.2-ka climatic oscillation. We found significant changes both in terrestrial vegetation and lake diatom assemblages in the northern slope of the Retezat Mts between c. 8300 and 8000 cal. yr BP. Rapid changes in relative frequencies and pollen accumulation rates of the major deciduous pollen types associated with peaks in microcharcoal accumulation rates suggested that vegetation disturbance mainly took place in the mixed-deciduous forest zone, where woodland fires partially destroyed the populations of Fraxinus excelsior, Quercus, and Corylus avellana and facilitated the establishment of Carpinus betulus in the forest openings. The diatom record furthermore showed the spread of a planktonic diatom species, Aulacoseira valida, at 8150 cal. yr BP, coincidently with a short-lived expansion of C. betulus. Since diatom blooms mainly occur in spring in the Retezat Mts, increased spring water depth and increased water turbulence were inferred from these data. The expansion of C. betulus against F. excelsior and C. avellana at the same time suggested a modest increase in available moisture during the growing season. Taken together, these data imply that during the 8.2-ka event, winter and spring season available moisture increased, while summers were characterized by alternating moist/cool and dry/warm conditions. [ABSTRACT FROM AUTHOR]

Within the framework of a regional research project on wetlands as cultural heritage sites, an attempt was made to examine the natural and anthropogenic causes driving the vegetation dynamics and exploitation of a small mountain wetland. To assess its potential use as an archive of the landscape history, an environmental archaeology approach was used: palaeoenvironmental data from traditional pollen sampling by coring were matched with stratigraphic information from an excavation area of several square metres, and plant micro- and macroremain analyses (e.g. pollen assemblages, micro- and macrocharcoal, morphological and dendrochronological features of waterlogged tree trunks) were compared in order to evaluate them as effects of different environmental factors and to pinpoint these factors. In this paper, the focus is set mainly on the results originating from pollen analyses of a core drilled in the peat-bog, a few metres from the stratigraphic excavation. The start of peat deposition, sometimes coinciding with human activity, was dated around 10,000 cal. BP. The impact on the vegetation surrounding the site is clearly recorded in the pollen assemblages only from the Roman period (2010–1820 cal. BP) even though a long history of human presence is archaeologically documented in the area since the Palaeolithic. Since that time, the abrupt decline of fir favoured the final spread of beech which, in turn, in the Middle Ages (1180–790 cal. BP) leaves space to grassland exploitable for pasture and for agro-silvi-pastoral activities. This site has proven to be of great importance for the Holocene history of the silver fir. [ABSTRACT FROM PUBLISHER]

The littoral site of Ifri Oudadane is one of the most important recently excavated sites in the Mediterranean Maghreb. The shelter presents Epipalaeolithic and Neolithic layers and therefore offers the possibility to investigate the Neolithic transition in the region. Besides introducing the archaeological context, this paper focuses on palaeobotanical data in order to reconstruct Holocene environmental change and human use of plant resources for the period c. 11 to 5.7 ka cal. BP. Results show intense landscape transformations resulting from anthropic and climatic factors. First human occupations start at the beginning of the Holocene with favourable conditions in this otherwise harsh semi-arid stretch of land. A wooded environment with evergreen sclerophyllous oaks and riparian forests is documented and exploited by hunter-gatherers. From c. 7.6 ka cal. BP farming activities are well attested together with significant human impact, herding pressure and a progressive decline of arboreal components. After 6.6 ka cal. BP conditions become less favourable and markers for aridity increase. Riparian taxa disappear (Alnus) or decrease (Fraxinus, Populus, Salix); shrubs (Tamarix) and grasses (Artemisia) increase with a degradation of forest into shrubland (macchia). During 6.6 and 6.0 ka cal. BP there is a general occupation gap in arid and semi-arid Morocco and evidence for that change is also found in the alluvial deposits of the Moulouya, NE Morocco. Indicators for food production decrease at the same time and the site is abandoned during the first half of the 6th millennium cal. BP. [ABSTRACT FROM AUTHOR]

This paper presents a pollen and charcoal record from a forest hollow located in northern Germany. The initial stand-scale colonization and subsequent expansion of the species Fagus sylvatica (European Beech) is examined and compared with examples from southern Scandinavia. In the early Holocene, a diverse forest stand is present. The recording of Fagus sylvatica in nine contiguous samples over the time period 8600–7950 cal. yr BP, constrained by three AMS dates, suggests its presence close to the hollow. This early occurrence is critiqued against the current paradigm of mid- to late-Holocene Fagus sylvatica spread in northern Central Europe. Between 6200 and 2900 cal. yr BP, Fagus sylvatica was a minor constituent of the forest community but did not expand despite periods of favorable conditions including relatively open forest landscape, wetter-cooler climatic conditions and a suitable fire regime. The eventual expansion of Fagus sylvatica, around 2900 cal. yr BP, is initiated by significant anthropogenic disturbance around the hollow. After the initial phase of expansion, its growing importance in the forest was potentially aided by a period of wetter-cooler conditions and a switch in the fire regime from one of regular episodes, to one of sporadic occurrence. Two fire events and an increase in anthropogenic activity occur at the same time as the decline in the relative abundance of Fagus sylvatica at 1200 cal. yr BP. This site highlights the strong anthropogenic influence on the species dynamics throughout the late Holocene. [ABSTRACT FROM AUTHOR]

In Mediterranean and north-African regions, cultural trajectories have shown trends sometimes coincident with climatic changes. The mid Holocene was a period of intense changes in climate, and in environmental and cultural systems. This paper reports pollen and charcoal studies from these areas aiming at presenting how impressive cultural changes frequently coincided with critical climate oscillations. Three of the main dry events of key relevance for climatic—cultural changes were selected to discuss this topic: c. 8200 cal. yr BP, c. 6000 cal. yr BP, and c. 4200 cal. yr BP. Five examples from on-site case studies were reported: (1) Wadi Teshuinat area (Fezzan, Libya, Central Sahara); (2) Benzù cave (Ceuta mountains, Spain, NW Africa); (3) La Vaquera Cave (Central System, Spain); (4) Terramara di Montale (Po Plain, Northern Italy); (5) Arslantepe (Eastern Anatolia, Turkey). Their archaeobotanical record helps to recognise and date human presence and activity in different territories. In these examples, anthropogenic signals and comparisons with other sites could be useful to distinguish climate signal from human impact in pollen records. Charcoals are evidence of human activity in cases which are not shown by pollen. Overexploitation of thinned plant resources, including overgrazing, accelerated the evolution towards xeric conditions during drying climatic phases. Humans enforced the aridity crisis and enhanced its signal in palaeoclimatic records. Sometimes, changing exploitation strategies and movements led to the onset of new cultures. Nevertheless, the onset and decline of a culture are very different critical phases, and different agents must have been involved in their occurrence. The Bronze Age marked the environment more than the Neolithic, probably because there is a relation between improvements in knowledge, cultural changes and the evolution of complex forms of land exploitation. [ABSTRACT FROM AUTHOR]

This paper explores the general correlations between fire and grass/tree relationships, as represented by fossil charcoal and pollen, from different vegetation types in the savanna ecosystems of the neighbouring Kruger (KNP) and Limpopo (PNL) national parks. Our analysis suggests that the basic presumption that fire is a main driver of vegetation dynamics in the savanna ecosystem by suppressing tree seedlings and encouraging grasses needs to be re-examined. An improved approach is to understand how fire may act both as a negative and positive feedback in different vegetational phases and both as a driver and responder in transitions between phases. The correlation between arboreal pollen (AP) percentages and charcoal influx suggests that in the grassland phase (< 5% AP), fire acts as a driver of woody recruitment and as a positive feedback, i.e. potentially driving the system to shift into a savanna phase. In the savanna phase (5—10% AP) fire limits woody recruitment and acts as a negative feedback in maintaining the savanna. Thus, in the savanna phase other factors than fire alone drive the transition from savanna to woodland-forest. In the riparian phase, where evidence of farming is present particularly from AD 1600 onwards, fire appears to facilitate tree recruitment where AP ranges between c. 10 and 20% AP. Though a decline in AP abundance can be seen contemporaneously with charcoal peaks, our analysis suggests that overall, human-induced fires do not seem to have a negative impact on woody cover. Our results have implications for fire management as riparian-dominated phases and savannas with a sufficient woody cover are less sensitive to changes in fire policies than open grasslands that may, with a change in fire frequency, change into another state. [ABSTRACT FROM PUBLISHER]

This paper presents and discusses the use of soil charcoal analysis (pedoanthracology) to reconstruct past forest dynamics in a larch forest of the upper Guil valley (French Alps, Queyras). We also discuss the role of anthropogenic fire in forest dynamics. The radiocarbon dates from this site demonstrate that arolla pine (Pinus cembra) and larch were present in the area since 7566-7673 cal. BP and 5934-6123 cal. BP, respectively. The identification of a piece of charcoal to fir (Abies alba) dated to 5734-5908 cal. BP suggests that this species was present at 1980 m a.s.l. since c. 6000 cal. BP and had a higher ecological tolerance than previously assumed. The cover of larch forests has increased since the second half of the Holocene because of anthropogenic practices (eg, clearing with fire, cattle grazing). However, today, owing to the abandonment of pastoral practices, the arolla pine has become dominant, which greatly modifies the forest structure and the landscape. [ABSTRACT FROM AUTHOR]

We present a thematic set on pedoanthracological research. In this paper a comparative analysis of soil wood charcoal from calcareous grasslands and pollen from an alluvial sediment profile has been carried out to reconstruct the history of calcareous grassland habitats in the Franconian Jura. Seven tree and shrub species (groups) were recorded from soil charcoal. Charcoal from Pinus dominated all spectra, indicating open forests or even less intensively grazed grasslands, which is supported by findings of remains of Juniperus and Ligustrum. Charcoals from Fagus, Quercus and Abies, indicating more closed forests, were comparatively rare. AMS radiocarbon datings assigned the charcoals to the period of the Roman Empire, the late Middle Ages and the early Modern Times correlating with the peaks of microcharcoals in the sediment profile. Juniperus pollen was used as indicator of calcareous grasslands. Plantago lanceolata, Galium type, Apiaceae, Ranunculaceae and Ballota/Galeopsis pollen-types were significantly correlated with the occurrence of Juniperus and identified as further indicators. Pinus was selected as an indicator for open forests. Pollen of all indicator species occurred throughout the pollen profile starting in the Iron Age. The main peak of grassland indicator species pollen types was in the high Middle Ages. Maxima of Pinus pollen have been recorded in the periods of the Roman Empire and the late Middle Ages. We suggest extension maxima of less intensively grazed calcareous grasslands during the Roman Empire period and during the late Middle Ages and of intensively grazed grasslands in the high Middle Ages in the latter case correlated to intensive mining activities north of the study region. Increase in Pinus and the conversion of open into woody grasslands in the late Middle Ages/beginning of Modern Times was triggered by the abandonment of arable farming due to the decline of human population caused by pest diseases. [ABSTRACT FROM AUTHOR]

This paper presents the anthracological results of Cova de la Guineu. This cave, which is located at the NE of the Iberian Peninsula, has provided charcoal samples from the early Neolithic to the Iberian period enabling the identification of different phases on the basis of flora assemblage interpretation. The results show how Mediterranean forests have been present since the early Holocene stages. At the early phases of the sequence the assemblage records dominant meso-screrophyllous taxa (deciduous Quercus, Taxus baccata), then thermophilous taxa (evergreen Quercus) spread, and finally a late phase of transformation dominated by thermophilous and heliophilous taxa (Mediterranean Pinus). The interpretation and discussion deals with the development and transformation of primary and secondary forests due to human disturbances and climatic variations. The anthracological record from Cova de la Guineu suggests that both elements were important and define the evolution of vegetation during the Holocene in the region. [ABSTRACT FROM AUTHOR]

The lower Yangtze, eastern China, was colonized by several Neolithic and Bronze Age cultures giving rise to possibly the highest concentration of prehistoric sites in the world. Early Neolithic cultures in the delta region cultivated rice (Oryza sativa) and agricultural developments appear to have occurred throughout the Neolithic with abrupt socio-economic changes possibly associated with the terminal Neolithic. Given the extensive history of environmental exploitation and well-preserved archaeological sites, the Yangtze delta is an ideal setting to explore the complex interactions between humans and their environment. Multiproxies of environmental changes, namely pollen, charcoal and phytoliths, in a 14C AMS-dated sequence of sediments from an exposed profile at Qingpu, Yangtze delta, were investigated. 14C AMS dating indicates that the age range of the sedimentary sequence analysed is from c. 1800 to 6000 BP, and therefore encompasses the terminal Neolithic and subsequent Bronze Age in the region. This paper reviews this sediment-based evidence in the light of current understanding of human-environment interactions during a critical phase of the development of the Yangtze delta and associated human cultures. [ABSTRACT FROM AUTHOR]

The Western Liaohe River Basin in northeastern China is one of the cradles of ancient Chinese civilization. Archaeological records from this region indicate that human occupation began about 8000 years ago and that agriculture and pastoralism were important activities from an early stage. Very little is known, however, about the effects that these activities had upon the landscape. This paper presents the results of a palaeoecological study from a 3.6 m sedimentary sequence in a relict oxbow lake in the Western Liaohe River Basin of southeast Inner Mongolia. The 5400-yr sequence indicates that human activities had a noticeable impact on an apparently open landscape. Buckwheat cultivation began as early as 5400 cal. yr BP with intensification of agricultural activities from approximately 4700 cal. yr BP. Nitrophilous plants such as Solanum and Cerastium, and also Artemisia were growing in the region at certain times, linked with fluctuations in the δ15N record and probably indicative of increased pastoralism and unintentional/intentional manuring. Burning was probably used for clearance of the steppe vegetation for agriculture with a close relationship apparent between increased influx of microfossil charcoal and the presence of buckwheat. Superimposed upon this record of human impact is also clear indication of three significant intervals of climate change between 2900 and 2600, 1200 and 600 and 600 and 30 cal. yr BP. The latter two are discussed in relation to the 'Mediaeval Warm Period' and 'Little Ice Age' apparent in sedimentary sequences across the Northern Hemisphere. Discussions are therefore made in terms of the impact that both climate change and ancient Chinese civilizations had upon shaping the present day landscape and vegetation. [ABSTRACT FROM AUTHOR]

Interactions between Holocene environmental changes and human subsistence strategies in semi-arid parts of eastern Africa are relatively poorly understood because of a paucity of sites where contemporaneous archaeological and palaeoenvironmental records are preserved. This paper presents new AMS 14C-dated palaeoenvironmental evidence of mid- to late-Holocene vegetation changes, in the form of pollen, charcoal, mineralogical and δ13Cbulk data, from a floodplain location on the Laikipia Plateau, Kenya, and in the context of information on modern plant–environment relationships, existing and new archaeological and historical data, and published palaeoclimatic records. Although relatively poorly resolved, the evidence indicates more wooded and relatively humid conditions compared with the present from before c. 6600 BP to c. 1900 BP. Evidence for vegetation changes over the last two millennia is more finely resolved and indicates increased burning and the expansion of fire-modified Acacia bushland c. 1900 BP and grassland c. 1700 BP. Burning to improve and extend pasture, and possibly to eradicate disease-prone habitats, may have been facilitated by prolonged periods of moisture deficits that might also have facilitated the spread of food production technologies. Vegetation changes c. 700 BP are associated with evidence for the occurrence of fires locally and could represent the activities of people and their animals close to the study site. [ABSTRACT FROM AUTHOR]

This paper presents a reconstruction of the Holocene palaeoenvironmental evolution in the central São Paulo State (Brazil) based on anthracological analyses, in association with soil isotopic composition (δ[sup 13]C) and radiocarbon dating from four sites. Anatomical identification of charcoal particles allows the reconstitution of past plant associations, and consequently of the vegetation and climate history. Rather precise interpretations may be achieved when associating anthracology and soil δ[sup 13]C analysis. In the early Holocene, climate was dry and an open cerrado vegetation (savanna) covered most of this area. A cerradão (forested savanna) or a semideciduous forest existed in the more humid localities. After 3500/3000 [sup 14]C yr BP the climate was more humid, similar to the present, leading to the establishment of forested vegetation in all the studied sites. Comparison of these results with various palaeoenvironmental studies carried out in the Brazilian phytogeographical zone of cerrado and semideciduous forest suggests that at least its greater part presented a similar trend in the climatic evolution during the Holocene. This phytogeographical zone presented a dry climate during the early Holocene, then a more humid climate during the late Holocene. Climatic conditions similar to the present appeared from 5000 to 1000 yr BP, depending on the site. [ABSTRACT FROM AUTHOR]