Towards the reconstruction of the Holocene vegetation history of Lower Provence: two new pollen profiles from Marais des Baux

Two new¹⁴C-dated Holocene pollen profiles from Marais des Baux, Bouches-du-Rhône, France, are presented. The record begins in the Younger Dryas, when the vegetation consisted mainly of grasses and mugwort (Artemisia). The Preboreal was marked by a transitory expansion of pine forests and was followed by the establishment of a rich deciduous oak-forest that included hazel (Corylus) and elm (Ulmus). During the Boreal, hazel played a dominant role within the oak-forest. The oak forests, which includedQuercus ilex, achieved a major expansion during the Atlantic period. The Subboreal was characterised by the regional establishment of, firstly, fir (Abies) and then beech (Fagus). The spread and expansion of beech coincides with the first clear evidence for farming. Agricultural activities brought about the decline of deciduous oak-forest. During the Subatlantic, forests in the vicinity of Marais des Baux were cleared for farming. Cereal growing, which included rye cultivation, was of considerable importance. Three noteworthy characteristics that serve to differentiate the Holocene vegetation history of the low-lying Provence region from other French regions are as follows: 1) the early establishment (from the onset of Preboreal) of low altitude mixed forest; 2) the expansion during the Subboreal of fir and beech in low altitude areas with a Mediterranean climate and, 3) the exceptional taxonomic richness of the pollen assemblages (120 identified taxa) and the presence of borealalpine and Euro-Siberian taxa that no longer exist in Lower Provence.     

Late-glacial and Holocene woodland dynamics and land-use history of the Lower Oder valley, north-eastern Germany, based on two, AMS14C-dated, pollen profiles

High-resolution Holocene pollen profiles from lakes Großer Krebssee and Felchowsee, in the Lower Oder valley, north-eastern Germany, are presented. The Großer Krebssee profile includes a Late-glacial sequence. These investigations have been carried out in the context of a programme of archaeological excavation. AMS radiocarbon dates (26 in all) based on pollen concentrates have been used to provide a chronology for the pollen records. Holocene forest history and human impact are reconstructed for contrasting landscapes, namely, the Neuenhagener Oderinsel in the Lower Oderbruch (Großer Krebssee profile) and the more fertile Uckermärker Hügelland (Felchowsee profile) that lies immediately to the north. Both landscapes were glaciated during the Pomeranian stage of the Weichselian. New information on the spread of trees, includingTilia, Fagus and Carpinus, at both regional and local level, is presented. Five major phases of intensive human activity are recognised, the most intensive activity of the prehistoric period occurring in the Neolithic (Großer Krebssee profile). Differences between the records is explained in terms of local habitat, especially edaphic conditions, settlement history and also the pollen source area, the profile from the much larger Felchowsee lake providing a record of environmental change that is more regional in character.     

Towards the vegetation and settlement history of the southern Dobrudza coastal region, north-eastern Bulgaria: A pollen diagram from Lake Durankulak

Palynological investigation and radiocarbon dating of a 6-m core from lake Durankulak, north-eastern Bulgaria, enables vegetation development and human occupation from ca. 5500–5300 cal. B.C. onwards to be traced. Steppe vegetation that included with groves of deciduous trees asQuercus, Ulmus, Carpinus belulus andCorylus changed to a forest-steppe after 4000 cal. B.C. The archaeopalynological record indicates three distinct phases of human activity as follows: (1) 5300–4200 cal. B.C. (late Neolithic and Eneolithic) during which farming, that included a substantial arable component, was pursued, (2) 3500–3000 cal. B.C. (transition to early Bronze Age) when stock rearing appears to have dominated, and (3) after 1300 cal. B.C. (late Bronze Age) when arable farming again assumed importance. The palynological data correlate well with the rich archaeological record for human settlement that is available for the region from late Neolithic times onwards.     

New palynological and tephrostratigraphical investigations of two salt lagoons on the island of Mljet, south Dalmatia, Croatia

In the sediments of both of the investigated lakes, the tephra from the Mercato-Ottaviano eruption (Vesuvius, southern Italy) (ca. 7900 B.P.) could be identified. The palynological investigations show that from ca. 9000-7200 B.P. (8000-6000 cal B.C.) deciduous oak forests predominated, with only a few representatives of Mediterranean vegetation. At the transition to the central European Atlantic Period those forests changed to an open vegetation type, dominated byJuniperus andPhillyrea. At about 5500 B.P. (4400 cal B.C.), theJuniperus-Phillyrea vegetation was replaced byQuercus ilex woodland that still occurs on the island of Mljet today and is considered to be the natural vegetation of the Dalmatian coastland. The associated vegetation of theQ. ilex forests changed several times. At the beginning of theQ. ilex period,Juniperus values were still high, but soon they decreased andErica spread. In more recent times theQ. ilex forests were partially replaced by plantations ofPinus halcpensis. Indicators of human impact are sparse throughout the pollen record. Clear evidence for human influence exists only from ca. 3100 B.P. (1300 cal B.C.) whenJuglans andPinus halepensis were introduced to the area. Later,Olea andSecale cultivation can be suggested and further spreading ofJuniperus indicates use of the land as pasture.     

Vegetation history and lake-level changes from the Younger Dryas to the present in Eastern Pyrenees (France): pollen, plant macrofossils and lithostratigraphy from Lake Racou (2000 m a.s.l.)

A multi-proxy palaeoecological investigation including pollen, plant macrofossil, radiocarbon and sedimentological analyses, was performed on a small mountain lake in the Eastern Pyrenees. This has allowed the reconstruction of: (1) the vegetation history of the area based on five pollen diagrams and eight AMS¹⁴C dates and (2) the past lake-level changes, based on plant macrofossil, lithological and pollen analysis of two stratigraphical transects correlated by pollen analysis. The palaeolake may have appeared before the Younger Dryas; the lake-level was low and the vegetation dominated by cold steppic grasslands. The lake-level rose to its highest level during the Holocene in the Middle Atlantic (at ca. 5060±45 b.p.). Postglacial forests (Quercetum mixtum and Abieto-Fagetum) developed progressively in the lower part of the valley, while dense Pinus uncinata forests rapidly invaded the surroundings of the mire and remained the dominant local vegetation until present. The observed lowering of the lake levels during the Late Atlantic and the Subboreal (from 5060 ± B.P. to 3590±40 b.p.) was related to the overgrowth of the mire. The first obvious indications of anthropogenic disturbances of the vegetation are recorded at the Atlantic/Subboreal boundary as a reduction in the forest component, which has accelerated during the last two millennia.     

Long-term human impact as registered in an upland pollen profile from the southern Black Forest, south-western Germany

A detailed,¹⁴C-dated, pollen profile from Steerenmoos, a raised bog in the uplands of the southern Black Forest (Schwarzwald) is presented. The Late-glacial and early Holocene vegetation history conforms to the known pattern of forest dynamics for that region. At ca. 6100 cal. B.P.,Abies replaced the mixed oak forest, which is in contrast to adjacent regions whereFagus spread beforeAbies. From the Subboreal onwards,Fagus expanded and slowly largely replacedAbies. The mire developed from a fen to a raised bog. The mountain pine (Pinus mugo ssp.rotundata) on the present-day bog surface is a result of medieval burning. Cereal pollen are first recorded in the Neolithic (7600 cal. B.P.) and there is a closed curve forPlantago Lanceolata — a good indicator of human impact — since the Bronze Age (4000 cal. B.P.). On the basis of the cereal pollen record nine human impact phases (HIP) are described. HIP 1 and 2, which are short, date to ca. 7600 and 6700 cal. B.P., respectively, in a mixed oak forest context and are characterized by declines inCorylus, Tilia, Ulmus and bySalix (but no major deforestation) and peaks in charcoal and loss-on-ignition curves. HIP 3 and 4, which are short and weak, date to ca. 6000 and 5300 cal. B.P., respectively, and occur in the context of anAbies alba forest. The Bronze Age and Iron Age HIPs 5-7 are more intense and of longer duration than the Neolithic phases and result in a decline inAbies and an increase inFagus. The early medieval HIP 8, although rather weak, probably finds expression also in an archaeological artefact, namely a dug-out boat from the near-by Schluchsee. Finally, the late Medieval HIP 9 resulted in a major transformation in the landscape. It is argued that the earlier HIPs are not a reflection of distant events in the lowland valleys of the Rhine, Danube or Neckar but reflect more or less local developments.     

Vegetational and environmental history during the Holocene in the Esbjerg area, west Jutland, Denmark

A pollen diagram from a site in the Esbjerg area, western Denmark, is used for reconstruction of the Holocene vegetational and environmental history there. During the Atlantic there was a parallel development of the landscape to that of other areas in Jylland (Jutland). From the late Neolithic onwards the development took its own course related to the approaching North Sea, which periodically inundated parts of the Esbjerg area. The record reflects landscape development in a formerly marine valley where sediments seem to be missing from parts of the Bronze Age and the early Iron Age. Consequently the landscape development during these times is only reflected in glimpses in the vegetation record, which shows gradually more open woodland and increasing human impact. During the late part of the Iron Age, Viking period and Middle Ages, the woodland was diverse in taxa but became increasingly open, finally reaching a stage during which there may have been too little wood even for daily use. At the same time the use of the land intensified. During the Sub-Atlantic, the Esbjerg area offered good natural resources with extensive grazing areas in the marine marshes in addition to good possibilities for farming and use of the woodland on higher ground, but devastating floods occurred.     

Studies on the vegetation history of Lake Varna region,northern Black Sea coastal area of Bulgaria

On the basis of pollen analytical investigations of two cores from Lake Varna and Lake Beloslav, the vegetation history of the Lake Varna region is traced back to the beginning of the 6th millennium B.C. A two-fold zoning system is used whereby the pollen diagrams are divided into pollen zones, based on tree migration patterns, and settlement periods. Pollen zone 1 is characterised by the absence of Carpinus betulus and Fagus sylvatica. The spread of hornbeam started at ca. 6500 B.C. (pollen zone 2) and beech at ca. 6200 B.C. (pollen zone 3), the latter being the last tree to spread into the region and considerably enrich the forests of the study area. Of the many pollen taxa representing plants that are favoured by open habitats and hence potentially indicative of human impact, only a few taxa are regarded as reliable indicators of human activity. These include above all Triticum-type, and also Secale and to a certain extent Plantago lanceolata, Rumex and Polygonum aviculare. The spatial pattern of settlements is somewhat different in the areas represented by the two profiles. At both sites the first period of settlement occurred during the 6th millennium B.C. (early Neolithic). After the Neolithic period, the main settlement periods of the Eneolithic and the Early and Middle Bronze Age are recorded. On the other hand, land-use history during the Greek and Roman periods is poorly recorded. Studies on the stratigraphy, diatoms and molluscs indicate that the sixth Black Sea transgression (6500–5800 B.C.), which reached –10 m, had considerable influence on the limnological environment.     

Mid to late Holocene vegetation and land use history in the Weald of south-eastern England: multiple pollen profiles from the Rye area

The High Weald is an unusually well-wooded area in southern England. A high proportion of this woodland is ancient, being formerly exploited as seasonal pasture and coppice. Multiple pollen profiles from the Rye area have been used to elucidate the origins of this cultural landscape. By combining sites with small and large pollen source areas, both local and regional patterns of vegetation change have been determined. The mid-Holocene Tilia-dominated woodlands were subjected to temporary clearance as early as the Neolithic. This woodland was more extensively exploited over a ca. 700 year period from the beginning of the Bronze Age. The main elements of the modern landscape (woodland, pasture and limited cultivation) can be traced back to a more intensive phase of human activity, which commenced in the late Bronze Age. A regional increase in Fagus sylvatica pollen ca. 750 B.C. probably reflects the use of the Wealden woods for pasturage. There is no palynological evidence that the fuel demands of the Roman iron industry resulted in widespread woodland destruction. The early Anglo-Saxon period appears to have been one of land-use continuity, with a second increase in Fagus pollen at ca. A.D. 700 corresponding to historical evidence for the presence of wood-pastures in the Weald.     

Mid- to late-Holocene vegetation history of Greater Exmoor,UK: estimating the spatial extent of human-induced vegetation change

This paper presents the results from three pollen profiles from a group of small spring mire sites on the southern edge of Exmoor in south west England. The size and topography of these sites allow detailed local landscape histories around each site to be reconstructed which broadly cover the mid- to late-Holocene. Comparison of the individual local landscape histories demonstrates the scale of spatial variation in vegetation around the upland edge, and facilitates understanding of human-landscape interactions from the early Neolithic onward. In the early Neolithic significant short-term woodland disturbance is recorded around the upland fringe, including clearance of oak-hazel-elm woodland, suggesting that the shift from Mesolithic to Neolithic is not marked by a gradual environmental transition. Following this, there is clear evidence of Neolithic management of upland heath using fire, presumably for the management of upland grazing. Woodland clearances are recorded throughout the later Prehistoric period; however, the use of multiple profiling suggests that woodland clearance is spatially discrete, even within an area of 4 km². Pastoral land use is dominant around the uplands until around 900–1,000 a.d., and there is no discernible Roman or post-Roman period impact in the vegetation, suggesting cultural stability from the late Iron Age to the early Medieval period. By 1,100 a.d., there is a shift to mixed arable-pastoral farming which appears to continue well into the post-Medieval period.     

Holocene forest dynamics and human impact in southeastern Estonia

Litho-, chrono- and biostratigraphical methods were applied in the examination of a 9.9 m thick sequence of laminated sediments in Verijärv, a lake in southeast Estonia. The vegetation history, which covers at least the time from 10300 cal b.p. to the present, was inferred from the core, which was taken from the deepest part of the lake and correlated with the studied and dated pollen diagrams nearby. Reconstruction of the past vegetation dynamics is based on pollen percentage, accumulation rate and human impact diagrams. During the Holocene two main shifts in vegetation dynamics occurred, the first one at about 7700 cal b.p. when the pine-birch forest was replaced by deciduous mixed forest, and the second at about 3200 cal b.p. marked by the regeneration of pine-birch-spruce forest. A catastrophic forest fire at about 3450 cal b.p. opened up the landscape and gave rise to erosion and the sedimentation of a thick clayey layer. The steep decline in the Alnus curve between 1500–1650 cal b.p. coincides with the start of the continuous Secale curve and evidence of extensive land-use.     

Vegetation changes and human occupation in the Patagonian steppe, Argentina, during the late Holocene

Vegetation changes during the late Holocene are interpreted from four fossil pollen sequences from two caves at the Los Toldos archaeological locality, Santa Cruz province, Argentina. Taphonomic processes are particularly taken into account in order to analyze the effects on the fossil pollen records of biotic factors such as human occupation and animals, and abiotic ones such as volcanic ash fall. Fossil pollen assemblages are interpreted using local modern pollen data. The main vegetation change occurred at ca. 3750 uncal b.p., when a shrub steppe of Asteraceae subf. Asteroideae with Schinus, Ephedra frustillata and a high proportion of grasses was replaced by a shrub steppe of Colliguaja integerrima and Asteraceae subf. Asteroideae. This change is synchronous with an archaeological record change and could be related either to moderate climatic variations or the effects of ash fall on the environment. Plant communities similar to the present-day ones were established in the Los Toldos area from ca. 3750 uncal b.p.     

Similarities and dissimilarities,synchronisms and diachronisms in the Holocene vegetation history of the Balearic Islands and Sicily

In some continental and island sites in the western Mediterranean basin, the Holocene vegetation and climate dynamics seem to show the same patterns in time and space. Nevertheless, different synchronous scenarios have been proposed from other south European, North African and Near Eastern pollen records from around the Mediterranean basin. Striking similarities and synchronisms have been found between Sicily and the Balearic Islands. These islands, although under different bioclimatic influences, show similarities in the main trends of vegetation and climate dynamics during the Post-glacial. Lago di Pergusa is the only natural inland lake in Sicily and because of its geographical location, has a good potential sensitivity to the climatic changes of the Mediterranean basin. Likewise, coastal sediments from Minorca and Majorca, the Balearic Islands, have similar peculiarities. The present-day environmental situation, now that most of the natural vegetation in these islands has disappeared, has been brought about either by a climatic trend towards increasing aridity or an increase in human activities. It seems clear that prehistoric human people alone could not have caused all the environmental changes recorded in the last millennia in both places.     

In vitro pollen embryogenesis in Nicotiana tabacum L. and its relation to pollen sterility,sex balance,and floral induction of the pollen donor plants

Pollen sterility, sex balance, and floral induction of the pollen donor plants were tested for a possible relation to embryogenesis from in vitro cultured tobacco pollen (Nicotiana tabacum L. var. Badischer Burley). The pollen grains destined to become embryos in culture (P-grains) were sterile for the donor plants as judged by their staining reaction with acetocarmine and fluorescin-diacetate, and by an in vitro germination test. They were produced in high frequency in flowers which exhibited a shift in sex balance towards femaleness. Sex balance could be measured by the relative length of pistil to stamens. High P-grain frequency, high pollen sterility, and a shift in sex balance towards femaleness could be induced by raising the donor plants under short days and/or low temperature (18–15° C) as compared to long days at 24° C. Short days and/or low temperature also reinforced floral induction, revealing that the tobacco variety Badischer Burley is a quantitative short day and low temperature plant and that the variety follows the rule that conditions of strong floral induction shift sex balance towards femaleness. At 12° C and short days, contabescent flowers were formed with completely sterile anthers containing a few and mostly collapsed P-grains. Based on these results, it is now possible to predict conditions by which haploids via pollen embryogenesis might be produced in high frequency from low-yielding and recalcitrant species.Abbreviations DPF dead pollen grain frequency - LD24 long days at 24° C - PD pollen dimorphism - P:S ratio of pistil to stamen length - SD15 short days at 15° C     

Woodland history of northern Greece from the mid Holocene to recent time based on evidence from peat pollen profiles

The woodland history of the northern mountainous parts of Greece is considered in the context of pollen profiles from bogs in Rhodopes, Lailias-Vrontou, Paiko, Voras and Pieria. In the time period covered by these diagrams (only those from Voras and Lailias extend back to the 7th millennium B.P.) the overall trends in the woodland history at the particular sites are comparable but there are also substantial differences that are attributed to the effects of human influence which varied in time, intensify and extent. The earlier phase, which corresponds to the Atlantic period of Firbas, is characterized by mixed deciduous woodlands with Quercus or Tilia the main components. This is followed by the phase (Subboreal) in which coniferous woodlands, which consisted of Abies and Pinus, dominated. In this time, Fagus gradually expanded. In the final phase (Subatlantic), Abies becomes more or less extinct and Fagus has a dominant role. These developments broadly correspond with those recorded in pollen profiles from Central Europe.     

Sources,impact and exchange of early-spring birch pollen in the Moscow region and Finland

The paper presents an assessment of birch pollen seasons in Finland and Russia. The re-analysis covered the period from 1994 to 2005 and was focused on suspected long-range transport events that were recorded both in Moscow and at several Finnish sites. In order to trace the origin of airborne pollen before the onset of local pollination, we used both aerobiological and phenological observations combined with forward and adjoint (inverse) dispersion model simulations. It is shown that, although the Moscow region is surrounded by extensive birch forests, it still receives substantial amounts of foreign pollen before local pollination. In the Moscow region, the sources of long-range-transported pollen are in the south and south-west, sometimes even in the east. In Finland, there are frequently cases, before the local flowering season, in which Finnish territory receives Russian pollen; however in the opposite direction, from Finland to the Moscow region, no transport episodes were unequivocally registered. Analysis of the end of the seasons was more problematic, due to contributions to pollen observations from local sources; this results in difficulties in the reliable identification of the long-range transport episodes. Apart from its short-term effects on the pollen seasons, long-range transport can have substantial impacts on the exchange of genetic material within Europe. A quick atmospheric pathway for gene transport can be important for adaptation of plants to a changing climate.     

Mid-Holocene environmental and human dynamics in northeastern China reconstructed from pollen and archaeological data

A pollen record from the Taishizhuang site (40°21.5′N, 115°49.5′E) located in the transitional forest-steppe zone near the present-day limit of the summer monsoon is used to reconstruct vegetation and climate. Quantitative biome reconstruction suggests that between ca. 5700 and 4400 cal. years B.P. temperate deciduous forest dominated the vegetation cover around the Taishizhuang site. After that time the landscape became more open and the scores of the steppe biome were always higher than those of the temperate deciduous forest except for two oscillations dated to ca. 4000 cal. years B.P. and ca. 3500 cal. years B.P. However, ca. 3400-2100 cal. years B.P. the common vegetation became steppe and the landscape was more open in comparison with the previous time interval. The results of the pollen-based precipitation reconstruction suggest that annual precipitation was ca. 550-750 mm (ca. 100-300 mm higher than present) during the mid-Holocene ‘forest phase’, and ca. 450-650 mm during the following ‘forest-steppe phase’. From ca. 3400 cal. years B.P. during the ‘steppe phase’ annual precipitation was similar to modern values (ca. 300-500 mm). Archaeological records from 100 sites prove the habitation of northeastern China during the prehistoric and early historic periods from ca. 8200 cal. years B.P., but do not provide evidence of the use of wood resources intensive enough to influence the regional vegetation development and to leave traces in the pollen assemblages. Both archaeological and palaeoenvironmental data support the conclusion that changes in pollen composition in northeastern China between 5700 and 2100 cal. years B.P. reflect natural variations in precipitation and not major deforestation caused by humans.     

Natural resources and agriculture during the Iron Age in Ostrobothnia,western Finland,investigated by pollen analysis

In Ostrobothnia, western Finland, the Viking period (A.D. 800–1050) in contrast to the rich Migration period (A.D. 400–550/600), is poor in archaeological finds. Archaeologists have interpreted this as indicating a break in settlement continuity. Palaeoecological investigations using pollen analyses and radiocarbon dating of peat cores from ten sites show that field cultivation and animal husbandry have taken place continuously throughout the entire Iron Age in Ostrobothnia. Slash-and-burn cultivation was not of importance in the studied area, but small-scale cereal cultivation occurred on permanent, tilled and manured fields. The Iron Age agriculture was largely dependent on animal husbandry and therefore was located close to the sea because the natural, highly productive shore meadows were an indispensable fodder resource. As a consequence of the progressive rapid change of the natural environment caused by the flat topography and land upheaval, the settlements were regularly relocated to keep pace with the westwards retreating sea. Settlement continuity in Iron Age coastal Ostrobothnia has to be looked upon in a regional rather than a local perspective because of the changing landscape. The results of this palaeoecological study, in which investigations were carried out in several parts of the region, demonstrate regional settlement continuity throughout the Iron Age.