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Detailed palaeogeographical studies of the accumulative fan in the Serteyka River valley in W Russia and underlying biogenic deposits were carried out. The base of a representative core of biogenic sediments in the distal zone is dated to 1291 BC, while its top to 1631 AD. In this paper, palynological, plant macrofossils, Chironomide and Cladocera, geochemical, geochronological and sedimentological analysis were performed. Four phases of biogenic deposition were distinguished by pollen and geochemical analyses. Two of them coincide with the climatic fluctuation during Medieval Climate Anomaly and Little Ice Age. During the formation of the fan, overbank deposits were accumulated also, indicating numerous and intense floods, which are in line with the trend observed for other sites in this region. The accumulative fan is formed by lower, middle and upper deluvia and agricultural diamicton in its top. All units have specific sedimentological and geochemical features as well as low admixture of plant macrofossils. The beginning of the formation of this relief form dates back to the second half of the 17th century AD, and the end of the accumulation falls on the second half of the 18th century AD. Our work suggests that natural conditions had an impact on the formation and development of studied accumulative fan, however, the decisive factor causing the intensification of the slope processes were related with deforestation resulted from strong human impact, which was marked in palynological and macrofossils analyses (e.g. increase in the contribution of plants macrofossils related to agriculture). [ABSTRACT FROM AUTHOR]

This paper presents the study of modern pollen analogs from the Balearic Islands. While similar studies have been largely applied to mainland areas, research focused on modern vegetation dynamics on Mediterranean islands remains very rare. In this research, we combine vegetation surveys, pollen analysis and multivariate statistics to understand landscape composition. The main objectives of are: (1) to examine pollen-vegetation relationships in relation to environmental and land-use variables; (2) to understand modern pollen representation in a mosaic landscape structure; and (3) to propose pollen indicators that characterize the primary vegetation types from the Balearic Islands to better interpret past pollen records in Mediterranean island environments. Pollen results and Redundancy Analysis (RDA) distinguish three major groups: (a) Holm oak and box formations; (b) maquis and garrigues; and (c) anthropogenic and open habitats. Landscape form, mean decadal rainfall, mean decadal temperature, fire activity, trampling, slope percentage, wet/flooded soil, saline soil, distance to agropastoral cells, gHM index, domestic herbivory presence, agropastoral use, and soil type are the major variables explaining modern pollen assemblage variation in our research. Poaceae undiff., Plantago sp., Apiaceae undiff., Cerealia-t, and Cichorieae are highly correlated to human activities but should be interpreted cautiously when occurring in low values. Quercus ilex -t, Hypericum, and Buxus are correlated to humid locations while Pistacia, Pinus, Juniperus -t, and Olea to high mean decadal temperatures. Our study indicates how pollen analysis and multivariate analysis are powerful tools for characterizing the mosaic landscape, with special focus on the main vegetation types of the Balearic Islands. [ABSTRACT FROM AUTHOR]

Paleoenvironmental data from wet-meadow environments in the arid-semiarid region of Patagonia are still incipient and the paleoenvironmental records came from pollen sequences of caves and rockshelters. The main reasons to study wetland records are their undisturbed (by humans) sedimentologic continuity, in contrast to deposits in rock shelters and caves; and their regional presentation of environmental changes that can be compared to archeological data. The aim of this paper is to evaluate the past hydrological dynamic of a wet-meadow from Deseado Massif and its relationship with the human occupation. For this purpose, we present the results of the sediment and pollen analysis of Mallín La Primavera wet-meadow that provide a sequence starting in the mid-Holocene. The results indicate a lower water table in the mallín prior to 6900 cal yr BP. Sediment analysis indicates low energy sedimentation environment with flood events and very low energy streams. Human occupational data show chronological discontinuities in mid-Holocene in several regions of Patagonia and the southern cone. In the studied region, two chronological hiatuses (7828–6434 cal yr BP and 3005–2710 cal yr BP) where recognized that appear to correlate with shrub steppes, indicating dry conditions. These conditions may explain the lack of archeological radiocarbon dates in the area during this period. The integration of sediment and pollen results from the Deseado Massif indicates dry and windy conditions for the middle Holocene. The lack of archeological radiocarbon dates would have been influenced by the loss of moisture in water sources such as springs and their associated wet meadows (mallines). [ABSTRACT FROM AUTHOR]

This paper aims at reconstructing the population dynamics during the Neolithic and Bronze Age, c. 4500–500 cal. BC, in north-western Central Europe. The approach is based on the assumption that increased population density is positively linked with human activity and human impact on the environment, respectively. Therefore, we use archaeological 14C dates and palaeoenvironmental data from northern Germany and south-western Denmark to construct and compare independent proxies of human activity. The latter involves relative quantification of human impact based on pollen analysis and soil erosion history inferred from summarizing of dated colluvial layers. Concurring patterns of changes in human activity are frequently recorded on a multi-centennial scale. Whereas such multi-proxy patterns are interpreted to indicate relative population changes, divergent patterns are discussed in the context of proxy-related uncertainties and potential biases. Patterns of temporal distribution of increasing and decreasing human activity are understood as 'boom and bust' phases in population density/size. Based on the comparison of the three proxies, we identify five phases of growing (boom) and four phases of decreasing (bust) population. The boom phases date to ca. 4000–3500, 3000–2900, 2200–2100, 1450–1300 and 1000–750 cal. BC. The bust phases to ca. 3200–3000, 2400–2300, 1650–1500 and 1200–1100 cal. BC. [ABSTRACT FROM AUTHOR]

This paper introduces a special issue on The Changing Face of the Mediterranean: Land Cover, Demography, and Environmental Change, which brings together up-to-date regional or thematic perspectives on major long-term trends in Mediterranean human–environment relations. Particularly, important insights are provided by palynology to reconstruct past vegetation and land cover, and archaeology to establish long-term demographic trends, but with further significant input from palaeoclimatology, palaeofire research and geomorphology. Here, we introduce the rationale behind this pan-Mediterranean research initiative, outline its major sources of evidence and method, and describe how individual submissions work to complement one another. [ABSTRACT FROM AUTHOR]

Identifying evidence for hunter-gatherers in the palaeoenvironmental record is far from simple. Despite decades of research, few studies have demonstrated unambiguous palynological evidence of hunter-gatherers. This paper presents the results of high-resolution palaeoecological analyses of a peat sequence located within the vicinity of the pre-historic Yup’ik village of Nunalleq in southwestern Alaska. The aim of this research was to examine whether there are any discernible palaeoenvironmental impacts associated with the 15th–17th century occupation of the site. Presuming an ephemeral character to any palaeoecological signal, this study selected a sampling location approximately 30 m east of the limit of archaeological remains. Pollen, non-pollen palynomorphs and microscopic charcoal analysis were then used to generate a highly resolved (contiguous 1 cm) environmental history for the site. The results are striking and indicate that the activities of prehistoric Yup’ik hunter-gatherers at Nunalleq did leave a clear material trace in the palaeoenvironmental record. Through the application of high-resolution Pb210 and C14 dating and Bayesian modelling, these impacts were found to be concurrent with the occupation of the archaeological site. These findings suggest that not only can circumpolar hunter-gatherers leave a material palaeoenvironmental trace but that these traces may be used to accurately date such site activity in lieu of excavation. [ABSTRACT FROM AUTHOR]

In this paper, we presented a reply to the comments on modern pollen rain and interpretations about the Last Glacial Maximum (LGM) by D’Apolito et al. Carajás may be considered as a micro-hotspot of plant endemism, mainly related to edaphic conditions and presence of different micro-habitats for canga vegetation into ironstone domains. These plants developed several survival strategies, including morphological and physiological adaptations, which is difficult for comparisons with any other distinct biomes or ecosystems. Furthermore, inaccurate interpretation of pollen taxa and habitat types by the previous palynological studies in Carajás, which are keys points presented in Guimarães et al., were not questioned by D’Apolito et al. Therefore, incomplete pollen database, uncertainties about pollen descriptions and plant–pollen habitat, poor knowledge about pollen production and dispersion in edaphically conditioned areas, as well as missing of multiproxy evidences about geology, geomorphology, faciology, and geochemistry can make LGM interpretations a very challenging task. This can produce more noises than reliable signals of paleoclimate changes. [ABSTRACT FROM AUTHOR]

Pollen, non-pollen palynomorphs, charcoal and geochemical analyses of sediments from Lakes Salęt and Ruskowiejskie (NE Poland) were used to reconstruct vegetation changes in the former Galindia territory (Old Prussia) related to human activity and the climatic instability of the medieval period. Among archaeologists and historians, there is a widespread opinion that the permanent transformations of the environment in Prussia (south-eastern Baltic region) began not earlier than after its conquest by the Teutonic Order and resulted from its economic activity and intensive colonization. The impact of previous inhabitants of this land on the environment has been considered as definitely weak. Our results provide entirely contrasting evidence and demonstrate that strong and permanent deforestation started as early as in the early 11th century AD, in the pre-Teutonic Order time, and were associated with the economic activity of the Prussian Galinditae tribes. In this paper, we also discuss a possible interpretation of the medieval distribution patterns of Quercus. We assume that human activity catalysed and amplified both its spreading process and decline, primarily driven by the ‘Little Ice Age’ climatic deterioration. Our palynological results indicate the significant spread of Picea from ca. AD 1000, which we interpret as reflecting hydrological and climatic changes. Moreover, we hypothesize that the spread of Carpinus in the early medieval period (11th–13th centuries), which occurred in connection with more intense human activity, was largely because of woodland pasturing. [ABSTRACT FROM AUTHOR]

Transhumance agriculture formed a key component of subsistence strategies in the Norse economies of the North Atlantic, with evidence of shielings or sæters found in Norway, Scotland, the Faroe Islands and Iceland. It is frequently assumed to have played a role in Norse Greenland, yet little enquiry has been made into such activity. This paper seeks to address this deficit, presenting the first palaeoenvironmental study of a suspected Greenlandic shieling site in the uplands of the former Norse Eastern Settlement. Pollen analysis, 14C and associated proxies are used to date and assess the environmental and landscape impact of shieling activity. Evidence for vegetation disturbance associated with Norse settlement is indicated from c. ad 985, but the shieling itself is interpreted as having been established somewhat later (cal. ad 1050–1150). Initially the site appears to have been used exclusively for grazing of livestock and there is tentative evidence for the use of burning to stimulate the spread of pastures. Pollen influx figures suggest the intensification, or initiation, of hay production c. cal. 1225–1325 reflecting either the spread of settlement from the lowland valleys, or evolution of the site into a full farm in response to population pressure. A reduction of human impact cal. ad 1300–1390 suggests a reversion to shieling activity, indicating similarities to transhumance in northern Iceland. Abandonment of the site dates to cal. ad 1325–1415 and is in agreement with previous evidence from Norse Greenland. [ABSTRACT FROM AUTHOR]

Multiproxy pollen, sediment, plant macrofossil and subfossil insect analyses are used to explore environmental change at Stóra-Mörk in southern Iceland between ad 500 and 1500. Previous palaeoecological studies in Iceland have indicated that vegetation and landscape change rapidly succeeded the initial settlement of the island around ad 871, with strong environmental consequences. However, recent high-resolution studies in western and northern Iceland suggest that the timing and amplitude of these changes may be less uniform than previously assumed. The palaeoecological evidence from Stóra-Mörk shows an initially muted anthropogenic signal. Before the early tenth century, the area was characterized by damp birch and willow woodland. Large-scale human impact did not begin until after ad 920 when a change in land use to grazing and crop production is observed in the pollen, insect and plant macrofossil records. Shifts in vegetation and insect taxa and in aeolian deposition indicate that this activity resulted in woodland reduction, increased soil instability, eutrophication and land surface drying. The relatively late appearance of large-scale human impact at Stóra-Mörk is consistent with the tenth-century farm establishment suggested by the historical record, and the delay in settlement at the location may relate to an initial avoidance of labour-intensive woodland clearance and/or management of woodland resources. This paper adds to the emerging body of evidence that suggests that the scale and timing of the initial effect of the human presence on Icelandic environments was influenced by complex and varied climatic, landscape, vegetational and cultural factors. [ABSTRACT FROM AUTHOR]

After the last glaciation, around 4000 BC, silver fir (Abies alba Mill.) spread to the area that is now the Czech Republic. This spread was not restricted to high mountains, but also took place across both highland and lowland landscapes. Historical forestry records from around AD 1500 mention a massive expansion of Abies alba, favoured by forest pasturing, litter raking and selective tree cutting. According to the current interpretation of these historical records, this expansion in Czech forests was extensive and lasted until AD 1800. On the other hand, pollen data coming mostly from the Alps consider silver fir as a species that is extremely sensitive to human impact. In this paper, we compare historical forestry reports with pollen and charcoal data from the Czech Republic. Both pollen and charcoal records show that Abies alba reached its maximum during the Bronze (2200—800/750 BC) and Iron Ages (800/750 BC—AD 0). While charcoal records indicate that silver fir wood was important also during the High Medieval, pollen data show that the High Medieval and Modern times were periods of a general decline in Abies. Our data suggest that the expansion of silver fir documented by historical records was not general but rather fragmented, probably according to actual form and the intensity of human impact, as well as environmental conditions. These historical records have contributed much evidence regarding the wider ecological tolerance of Abies. [ABSTRACT FROM AUTHOR]

This paper compares a high resolution, near-annual pollen record from the Šijec raised bog (1194 m a.s.l., Pokljuka, Slovenia) with historical land-use maps in order to understand how the Alpine environment has altered because of changeable economic trends in the fifteenth, nineteenth and twentieth centuries AD. In the fifteenth century AD the study site was surrounded by mixed forest (Fagus, Abies, Picea, Quercus) and agricultural fields and pastures, but by the beginning of the nineteenth century AD the landscape had become more open, with very intensive agricultural land-use and grazing. The forest composition also changed: Fagus and Abies declined because of intensive grazing and ironworks (forest clearance and charcoal production). In the second half of the nineteenth and at the beginning of the twentieth century AD, forest recovered, but farming activities continued and, as a result of the forestry policy, Picea prevailed. After AD 1945 agricultural economy declined and mixed forests, which today cover more than 70% of land, are still expanding. [ABSTRACT FROM PUBLISHER]

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]

Modern proxy-calibration studies are a powerful tool for paleoecological interpretation. This paper analyzes the relationships among modern pollen rain, vegetation and altitude in the central Pyrenees, where several paleo-palynological studies have been developed, but a modern analog survey is still unavailable. The work analyzes the pollen content of moss polsters from different vegetation communities along an altitudinal transect, as well as the flora and vegetation using the Braun-Blanquet system. DCCA showed that altitude satisfactorily explains both vegetation (r2 = 0.988) and pollen (r2 = 0.841) gradients. Besides the complexity of pollen-vegetation relationships, some regularities were found to be useful for paleoecological and paleoenvironmental interpretation. In general, altitudinal vegetation and pollen patterns show similarities, but pollen belts and boundaries are less well defined, likely because of the homogenizing effect of upward wind transport. Palynological differentiation of montane from subalpine/alpine belts is straightforward from the trends of the more significant pollen types, mainly the low-altitude deciduous trees and the high-mountain herbs. Palynological differences between subalpine and alpine belts, which boundary coincides with the treeline, are more subtle and need quantitative criteria and complementary proxies. From an individual point of view, four main groups of pollen were distinguished, in relation to their usefulness as vegetation and altitudinal indicators: (1) very good indicators, (2) good indicators, (3) non indicators, and (4) allochthonous pollen types. The first two groups resulted to be useful as indicator taxa for modern analogs for paleovegetational and paleoaltitudinal reconstruction, while the latter two groups should be interpreted with caution in paleoenvironmental studies. [ABSTRACT FROM AUTHOR]

Assessment of the wild or cultivated origin of Olea europaea L. during the middle to late Holocene according to pollen analyses is of palaeoecological and evolutionary interest as olive is thought to be one of the earliest cultivated trees and is still one of the most important fruit trees of the eastern Mediterranean. This paper considers data from the Bronze-Iron Age harbour-town, Tell Tweini, of the Ugarit Kingdom, in the Syrian coastal lowland near Jableh (17 m a.s.l.) and from the Hellenistic-Roman Moatra-Bereket (1410 m a.s.l.), in the territory of Sagalassos, in Turkey's western Taurus Mountains. Both of these sites have recorded the rise and collapse of early eastern Mediterranean urban systems from 4200 to 1600 cal. yr BP. The Syrian data suggest that the Olea pollen-type originated from wild varieties during the Bronze and Iron Ages despite archaeological evidence for olive cultivation in the northern Levant. For Turkey, the results of the pollen-numerical analyses support the existing archaeological evidence of a wealthy oleoculture in Hellenistic and Roman Anatolia and suggest important anthropogenic pressures on local ecosystems. [ABSTRACT FROM AUTHOR]

This paper presents the results of simulated pollen counts from the central Scandes Mountains in Sweden which are used to examine the application of a pollen-based modelling approach to treeline fluctuations. Treelines are considered sensitive indicators of climate variability, and greater consideration of the palynological signal of treeline fluctuations is important in critical and rigorous use of pollen analysis to reconstruct variations in treelines. The approach presented here is to construct GIS-based models of the landscape (based on topographic and land cover attributes) onto which placement of different vegetation communities can represent changes in treelines in space (by adjusting the altitudinal positioning of treelines) and time (by using five time slices through the Holocene). The application of the POLLSCAPE model of pollen dispersal and deposition is then applied to generate simulated pollen counts for a large number (121) of sites placed across an altitudinal range in the simulated landscape. Comparison of simulated data to empirical pollen data from the region validates the approach through reasonable matching of the main trends in the pollen data sets. The success of the modelling approach is that it has helped to refine the process by which variations in fossil pollen assemblages are constructed, and also provides a tool by which the optimum sampling locations can be determined for treeline-focused work. [ABSTRACT FROM AUTHOR]

The Gunditjmara people developed a socio-economic system based on the modification of wetland ecosystems associated with the Mt Eccles lava flow primarily for sustainable production and management of the highly nutritious shortfin eel (Anguilla australis). This paper examines the environmental history of these landscapes since their inception about 30 000 years ago, through palaeoecological analysis of sediment cores from associated lakes and swamps, in order to contribute to an understanding of the causes and timing of cultural transformation. Two records cover the whole of the 30 000 year history of the landscape while two others provide evidence of change within the Holocene. A great deal of variation within the landscape is revealed, both temporally and spatially, with opportunities for human exploitation through the whole recorded period. Although most features of the records can be explained by natural landscape development and climate change, some human modification can be suggested from around the Pleistocene-Holocene transition while more obvious indications of management relating to eel aquaculture are evident from about 4000 cal. yr BP that appear to include adaptations to the onset of a drier and more variable climate. The study has implications for the explanation of intensification of settlement in Australia more generally within the mid to late Holocene. [ABSTRACT FROM AUTHOR]

Successful reconstruction of vegetation from fossil pollen data in the arctic and alpine tundra, and at the forest-tundra ecotone, is hampered by low pollen production of the major taxa in these environments and the likely dominance of the background pollen component. New approaches to the quantification of vegetation from pollen data (the REVEALS and LOVE models) rely on quantification of background and local pollen by applying models of pollen dispersal and deposition to modern pollen-vegetation survey work. To date, research within this emerging area has focused on lowland environments. This paper presents pollen productivity estimates (PPEs) from the forest-tundra ecotone derived from west central Sweden, discusses the relevant source area of pollen (RSAP) in this environment and estimates the background pollen contribution. The results suggest that the RSAP for moss polsters at the forest-tundra ecotone is c. 500 m, and that PPEs for the major forest tundra ecotone taxa show significant differences compared with previous studies from southern Sweden. Proximity to range limits (controlled by climatic factors) appears to be the main factor causing generally lower pollen production; however, individual taxa respond in different ways, depending on differences in growth behaviour, reproductive strategy and the species and subspecies that represent the pollen taxa. The background pollen component was dominated by arboreal taxa, and contributed c. 60% of the total pollen loading. Graminoids dominated the local component. The PPEs presented here are to date the most appropriate parameters to use for quantification of vegetation at the tundra treeline; however, the data demonstrate that caution needs to be exercised with regards to selection of appropriate PPEs for accurate quantification of taxa at their ecological range. [ABSTRACT FROM AUTHOR]

On the basis of sediment and pollen analyses of a radiocarbon-dated sediment sequence from Lake Joux in the Swiss Jura Mountains (west-central Europe), this paper presents a high-resolution record of lake-level and vegetation changes for the last millennium. The lake-level record makes it possible to determine that lowstands of the water-table dominated at c. AD 1200-1400, and from 1720 onward, with interruptions by short-lived rise events at c. AD 1340 and 1840. Highstands prevailed at c. AD 1100, and around AD 1450, 1550 and 1700. The comparison of the Joux lake-level record with a solar irradiance record based on cosmogenic nucleides supports the hypothesis of a major solar forcing of climate variations in west-central Europe over the last millennium. In agreement with other palaeohydrological records established in Western Europe and in the central North Atlantic Ocean, the Joux lake-level record suggests that, on a multicentennial scale, the period of the 'Little Ice Age' coincided in the European mid-latitudes with wetter climatic conditions, and probably with an increase in summer precipitation. Variations in the hydrological cycle appear to have been associated with changes in the general atmospheric circulation pattern, probably coupled with variations in oceanic circulation and solar activity. The Joux record also points to changes in water resources expected to result from ongoing global warming. Finally, despite the severe climatic conditions which prevail in the Joux Valley, the human impact history at Lake Joux over the last millennium seems to reflect political choices and economic context more than climatic changes. [ABSTRACT FROM AUTHOR]

Frank Oldfield's immense contribution to palaeoenvironmental science is summarized in relation to: pollen analysis, vegetation history and peat stratigraphy; palaeolimnology and 210Pb dating; environmental magnetism, catchment-lake relationships and soil erosional history; multiproxy approaches; PAGES; and editing The Holocene. The tribute includes an introduction to the 14 other papers in this Special Issue, which were inspired in diverse ways by this remarkable scientist. [ABSTRACT FROM AUTHOR]

Abstract: A total of 237 surface soil pollen samples were collected from less disturbed zonal communities, and a new surface pollen data set has been established in northern China. Pollen-climate parameter transfer functions using weighted-averaging regression and calibration partial least squares (WA-PLS) model as a tool to reconstruct past climate changes from pollen data, were tested with this new surface pollen data set. The results of cross validation showed that the method worked very well with precipitation (R = 0.94, R2 jack = 0.89, RMSEPjack = 69 mm, the safe dynamic range of the reconstruction was 40 mm~800 mm) and worked well with temperature (Tann: R = 0.84, R2 jack = 0.71, RMSEPjack = 2.0°C, the safe dynamic range of the reconstruction was -4°C~13°C; MTwa: R = 0.79, R2 jack = 0.63, RMSEPjack = 2.5°C, and the safe dynamic range of the reconstruction was 8°C~26°C), indicating that the surface pollen data set and WA-PLS reconstruction technique in this paper have strong potential for palaeoclimatic reconstruction. [ABSTRACT FROM AUTHOR]

Pollen analysis of a 48 m AMS radiocarbon-dated sediment sequence from the Guadiana estuary provides the first record of Lateglacial and Holocene vegetation history in the Algarve province of Portugal. This paper focuses on the record of terrestrial pollen taxa, which document a series of forest expansions and declines during the period 13 000 cal. BP to 1600 cal. BP and provide insights into climate evolution in southwestern Iberia. The main vegetation phases identified in the Guadiana valley are (1) Lateglacial interstadial (Allerød) forest with Quercus and Pinus under a temperate, moist, continental climate; (2) a Younger Dryas forest decline (Quercus) and expansion of pinewoods, xeric scrub and open ground habitats (with Juniperus, Artemisia, Ephedra distachya type, Centaurea scabiosa type) under arid and cold conditions; (3) an early Holocene forest/scrub/open-ground vegetation mosaic developing under a warm, dry and continental climate; (4) a maximum of Quercus forest and thermomediterranean evergreen taxa (Olea, Phillyrea, Pistacia) reflecting a warm, moist oceanic climate between c. 9000 cal. BP and c. 5000 cal. BP; and (5) the expansion of shrublands with Cistaceae and Ericaceae under a drier climatic regime and increasing anthropogenic activity since c. 5000 cal. BP. Holocene episodes of maximum climatic aridity are identified in the record of xerophytic taxa (Juniperus, Artemisia, Ephedra distachya type) centred around 10 200 cal. BP, 7800 cal. BP, 4800 cal. BP, 3100 cal. BP and 1700 cal. BP. Regional comparisons suggest a correlation of arid phases across southern Iberia and northwest Africa, which can be related to abrupt North Atlantic coolings (Bond events). [ABSTRACT FROM AUTHOR]

Quantitative reconstruction of past vegetation is one of the primary goals in Quaternary palynology and palaeoecology but still remains difficult. This paper proposes a model, REVEALS, that estimates regional vegetation composition using pollen from ‘large lakes’ that have small site-to-site variations of pollen assemblages even if vegetation is highly heterogeneous. Once these data have been used to quantify regional vegetation composition within 104-105 km², background pollen, one of the parameters crucial for vegetation reconstruction, can be estimated for smaller-sized sites, and incorporated into the Landscape Reconstruction Algorithm (LRA), a multistep framework for quantitative reconstruction of vegetation in smaller areas (≤/104 ha). Simulations using the POLLSCAPE modelling show that REVEALS can provide accurate estimates of regional vegetation composition in various landscapes and under different atmospheric conditions. If pollen assemblages from lakes that are much smaller than ‘large lakes’ are used, estimates of regional vegetation at individual sites could be significantly different from the expected values, and their site-to-site variation could be large. However, when pollen data from multiple lakes ≥100-500 ha in size are available, REVEALS can provide accurate estimates of the regional vegetation with relatively small standard errors. Quantitative reconstruction of regional landscape and vegetation change will be critical for testing some of the controversial hypotheses and concepts in global change and conservation research, such as the impacts of agricultural activities on global climate over the last 8000 years and the open-woodland hypothesis in northern Europe in the early Holocene. [ABSTRACT FROM AUTHOR]

This paper describes the LOVE (LOcal Vegetation Estimates) model for estimating local vegetation composition within the relevant source area of pollen. This model quantifies and then subtracts background pollen (ie, pollen coming from beyond the relevant source area) in order to arrive at a quantitative reconstruction of local vegetation. Parameters required for LOVE applications are pollen counts from target sites, the relevant source area of pollen of these sites, pollen productivity estimates and regional vegetation composition within 104-105 km². Regional vegetation composition is obtained using fossil pollen from large sites (≥/10² ha) with the REVEALS (Regional Estimates of VEgetation Abundance from Large Sites) model, the first step of the Landscape Reconstruction Algorithm (LRA) specifically designed for LOVE applications. POLLSCAPE simulations demonstrate that (1) regional vegetation composition can be used to predict background pollen at and beyond the relevant source area of pollen for given-sized basins, (2) LOVE with the LRA framework provides a robust and accurate estimate of local vegetation composition much better than vegetation reconstruction using pollen percentages alone and (3) although the relevant source area of pollen is difficult to estimate particularly in past landscapes, a proposed method using backward modelling of LOVE is effective to estimate the relevant source area in landscapes of unknown vegetation patchiness and heterogeneity. Thus, the LRA will also be useful to estimate indirectly changes in spatial structure of past vegetation and landscape caused by natural and anthropogenic forcing. [ABSTRACT FROM AUTHOR]

This paper describes our recent extraction of ancient DNA (aDNA) from Holocene pollen and discusses the potential of the technique for elucidating timescales of evolutionary change. We show that plastid DNA is recoverable and usable from pollen grains of Scots pine Pinus sylvestris from 10 ka and 100 years ago. Comparison of the ancient sequences with modern sequences, obtained from an extant population, establish a first genetic link between modern and fossil samples of Scots pine, providing a genetic continuity through time. One common haplotype is present in each of the three periods investigated, suggesting that it persisted near the lake throughout the postglacial. The retrieval of aDNA from pollen has major implications for palaeoecology by allowing (i) investigation of population-level dynamics in time and space, and (ii) tracing ancestry of populations and developing phylogenetic trees that include extinct as well as extant taxa. The method should work over the last glacial oscillation, thus giving access to ancestry of populations over a crucial period of time for the understanding of the relationship between speciation and climate change. [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]

In this paper we use a simulation approach to explore the effect of variation in taxon parameters and landscape patterning on relevant source area of pollen. We use the Prentice-Sugita model, assume constant atmospheric conditions and basin morphology, and take a reductionist approach to explore the behaviour of pollen dispersal and deposition in a simple landscape scenario. Individual factors within the scenario (pollen fall speed, relative pollen productivity, size of basic unit in the landscape mosaic, patch size, rarity of individual taxa and overall number of taxa present in the landscape) are varied while all other parameters are kept constant, thus permitting exploration of the role of different components of the system. These simulations suggest that, for basins of given size under fixed atmospheric conditions, the relevant source area of pollen is primarily an expression of the patterning of the different vegetation elements within the landscape. This has important implications for the interpretation of palaeoecological records and reconstruction of past environments. Reconstruction, especially quantitative reconstruction, requires some estimate of past relevant source area of pollen. If, as our results suggest, vegetation patterning is an important determinant of this, then it must also be taken into account when attempting to reconstruct past vegetation communities. [ABSTRACT FROM AUTHOR]

This paper examines the importance of palynological site selection criteria, specifically basin size, for the detection of vegetation mosaics and small- or local-scale human activity within a spatially diverse, mosaic landscape. Using a site selection strategy which recognizes landscape patchiness, pollen analyses from three small peat basins (10-56 m diameter) in an open, exposed upland valley (>250 m OD) provide records which are sensitive to local vegetation mosaics and small-scale, localized agriculture. The results indicate c. 4000 [sup 14]C years (4400 cal. years) of land use, with spatial and temporal variations in the valley. Contrasts between the sequences suggest that local pollen production remains an important component of the pollen rain deposited in small peat basins, even in open environments; this is especially true of palynological 'agricultural indicators'. By comparison, sites with regional pollen source areas underestimate the spatial diversity of the upland landscape, and are insensitive to small-scale human activity in an environment where the fragmentary distribution of soils suitable for agriculture favoured a small-scale, dispersed pattern of farming. It is therefore essential to match the spatial resolution of pollen records with the grain size or scale of variations in the environment under investigation in order to sense the scale of mosaics in vegetation and agriculture within patchy landscapes. [ABSTRACT FROM AUTHOR]

This paper examines the mid- to late-Holocene (c. 6850-1160 cal. yr BP) environmental history of Sierra de Gádor in southern Spain. The local vegetation dynamics are reconstructed through the palaeoecological record obtained from a lacustrine deposit situated at 1530 m. Various hypotheses are considered to explain the vegetation dynamics apparent in the palaeoecological evidence, including climatic change, fire occurrence and human activity. Although the vegetation in this region is sensitive to climatic change, threshold events driven by ecological factors are also apparent. Climatic events include a thermo-mesophytic optimum with abundance of deciduous trees and maximum lake water level found from c. 6850 to 5500 cal. yr BP. In contrast, changes in the frequency of major fire episodes appear to have shaped interspecific relationships and vegetation change, especially from c. 4200 cal. yr BP onwards. Biotic properties of the ecosystem such as the inertia of established tree populations, interconnected with competition adjustments, appear also to have played a role. Over the last two millennia, overgrazing, combined with natural and/or human-set fires, appears to have pushed mountain forests over a threshold leading to the spread of grassland, thorny scrub, junipers and nitrophilous communities. [ABSTRACT FROM AUTHOR]

To gain a better insight into the nature of palaeovegetation change in tropical ecosystems, more information needs to be gleaned from the limited number of fossil pollen records that exist. To achieve this, a detailed understanding of modern tropical ecosystems and the pollen they produce is required. To facilitate this, a practicable and effective mechanism for sampling modern pollen rain from the tropics is required. This paper presents a modified field methodology based upon three years of trapping experience in Noel Kempff Mercado National Park, Bolivia, and improved laboratory preparation methodologies. We demonstrate here a simple and very effective way to sample modern pollen rain in tropical environments using a funnel trap mounted on a stake containing cotton fibre as the trapping medium. [ABSTRACT FROM AUTHOR]