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1.
A high-resolution Late Pleistocene and Middle to Late Holocene pollen profile of regional significance is presented. The coring site is located in a mire between two lakes. Ober- and Unter-ückersee, in Brandenburg, north-eastern Germany. The study was carried out in an archaeological context. It provides information about the history of vegetation, climate and human impact in the ücker river valley and the surrounding hills, the Uckerm?rker Hügelland. Hence, it is an important contribution for the reconstruction of the past vegetation of this area of Brandenburg. Seven AMS 14C-dates based on pollen concentrates provide a chronology for the middle Holocene part of the profile. Phases of intensive human activity can be shown from the middle Neolithic times until the Roman Iron Age. Received February 1, 2000 / Accepted January 18, 2001  相似文献   

2.
A pollen diagram from the Ahlequellmoor in the Solling area shows the history of vegetation and settlement over the last 7,800 years. In the early Atlantic period mixed deciduous forest with mainly Tilia together with Ulmus and Quercus grew in the area. In the late Atlantic period Quercus became most abundant. Fagus spread in the Sub-boreal period at about 2700 B.C. Since ca. 900 B.C. the Solling was covered by beech forests with some oak. In prehistoric times woodland grazing is indicated. Only in Medieval times are two settlements in the vicinity of the Ahlequellmoor reflected in the pollen diagram. The earlier one is dated to about A.D. 750–1020, and may be connected with the former Monastery of Hethis, which is thought to have existed close to the fen from A.D. 815 to 822. The second Medieval settlement dates to the 11th–12th century. The large-scale woodland destruction of late Medieval and modern times is not clearly visible. The silvicultural measures of the last 200 years are reflected by increasing values of spruce and grassland taxa.  相似文献   

3.
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.  相似文献   

4.
5.
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.  相似文献   

6.
Aim To identify and interpret spatial patterns of vegetation and sedimentation during the Weichselian Late‐glacial. Location North‐eastern Germany and the adjacent fringe of north‐western Poland. Methods An inspection and comparison of palynological data from c. 150 sites. Results Open Vegetation phase I (Oldest Dryas = earlier part of the Meiendorf, 12,900–12,450 14C bp ) and the Hippophaë phase (Bølling = later part of the Meiendorf; 12,450–12,000 bp ) were rather homogeneous palynologically in the study area. Open Vegetation phase II (Older Dryas; 12,000–11,900 bp ) is strongly recorded in the northern part of the study area with relatively thick sediments (suggesting severe soil erosion), but it can hardly be traced 200 km further to the south. This is attributed to sea buckthorn (Hippophaë) shrubs persisting longer in the south due to higher temperatures, to Betula forests expanding earlier under the influence of a more humid climate or to a generally denser vegetation independent of the behaviour of Hippophaë and Betula. During the late‐glacial Betula/Pinus forest phase (Allerød; 11,900–11,000 bp ), pine (Pinus) forests dominated in the southern regions, whereas birch (Betula) forests prevailed in the north. Open Vegetation phase III (Younger Dryas; 11,000–10,000 bp ) was characterized by heathlands in the northern regions with scattered birches and with sedimentation dominated by in‐washed silicates. In the south, pine parklands occurred with sedimentation dominated by local primary production which had markedly decreased after the previous warmer vegetation phase. Main conclusions The differences in vegetation and sedimentation during the open vegetation phases are attributed to a colder climate in the north than in the south, probably related to a climatic gradient between the ice‐free continental central Europe and the decaying Scandinavian ice sheet. The vegetation patterns during the late‐glacial Betula/Pinus forest phase are attributed to edaphic differences between the predominantly till plains in the northern part of the study area and the prevailing sandy outwash plains and Urstromtäler of the southern regions.  相似文献   

7.
8.
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.  相似文献   

9.
A Late Pleistocene and Holocene sediment core from the nowadays terrestrialised portion of the Löddigsee in Southern Mecklenburg, Germany was palynologically investigated. The lake is situated in the rarely investigated Young moraine area at the transition from the Weichselian to the Saalian glaciation. The high-resolution pollen diagram contributes to the establishment of the north-eastern German Late Pleistocene pollen stratigraphy. The vegetation distribution pattern after the end of the Weichselian is in good agreement with other studies from North-eastern Germany, but also has its own characteristics. The Holocene vegetation development reveals features from the north-eastern and north-western German lowlands. A special focus was laid on the environmental history of the two settlements on an island within the lake (Late Neolithic and Younger Slavic period), which were preserved under moist conditions. Both settlements were constructed during a period of low lake level. Although there is evidence of agriculture in the area during the respective periods, the two island settlements seem to have served other purposes.  相似文献   

10.
We present a pollen record from a fen at the eastern shore of Brazo Sur south of Lago Argentino, Argentina (core BRS 1/06, 50°34′54″S, 72°54′52″W, 198 m a.s.l.). The coring site is located in the transition zone from humid grass steppe to Andean Nothofagus forest. With the exception of a mid-Holocene sand layer, the record covers the interval between 13,350 and 1,700 cal b.p., indicating that there could have been no recurrence of Late-glacial conditions in Brazo Sur, as has been suggested in the literature as having been contemporary with the Younger Dryas interval in the northern hemisphere. The Late-glacial and early Holocene periods at Brazo Sur are characterized by fluctuations between humid grass-dominated steppe associations and drier ones dominated by Asteraceae and Ericaceae. At the start of the Holocene, the pollen influx increased. Nothofagus dominance began by 7,700 cal b.p. probably due to increasing moisture. Present-day closed Nothofagus forest developed around 2,500 cal b.p., related to a further increase in moisture.  相似文献   

11.
A 9200 14C year fossil pollen record from a small kettle lake in central Maine, northeast U.S.A., records the development of nearby upland vegetation throughout the Archaic, Ceramic, and Historic periods of human history. The Early Archaic period (9000 to 8000 B.P.) began as open woodland dominated by Picea, Populus, and Larix, which was replaced by Pinus forest. During the Middle Archaic (8000-6000 B.P.) Tsuga-dominated forest, which developed ca. 7400 B.P., was followed by Pinus forest (ca. 6400 B.P.). The Late Archaic (6000-3000 B.P.) was a period of great transition; Tsuga forest developed again ca. 5700 B.P., but was abruptly replaced by northern hardwood forest ca. 4700 B.P. That Late Archaic expansion of hardwoods would have provided better forage for beaver. Coincidentally, boreal wetland mammals such as beaver (Castor canadensis) and muskrat (Ondatra zibethicus) increase in faunal assemblages of local archaeological sites, while remains of anadromous fish decrease. We postulate that the apparent increase in human populations throughout the region during the Late Archaic may be attributed to an increase in the resource base within both upland and wetland areas resulting from the development of hardwood forest in response to climatic cooling.  相似文献   

12.
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.  相似文献   

13.
The islands of Torres Strait occupy a shallow area of submerged continental shelf narrowly separating Cape York Peninsula, Australia, from New Guinea. The human history of Torres Strait is unique with respect to mainland northern Australia. Island vegetation, however, exhibits a strong affinity with the environments of the western lowlands regions of Cape York Peninsula and with the vegetation of seasonal tropical Australia in general. Cape York Peninsula is both climatically and biologically diverse, yet few pollen studies have been carried out in its seasonally tropical environments. A summary presentation of palynological results, tracing the nature of vegetation change in Torres Strait, offers a possible framework for vegetation changes in similar environments on mainland Australia and also provides an opportunity to explore the relationship between Quaternary change in humid-tropical Australian environments and their seasonal-tropical counterparts.Six pollen records from Torres Strait provide evidence of vegetation change and fire history over approximately the last 8000 years. Near-shore sediments reveal a Holocene succession in vegetation incorporating lower-tidal mangrove, upper-tidal mangrove, saltmarsh and freshwater swamp communities. Extensive stable mangrove communities dominated coastal Torres Strait between approximately 6000 and 3000 radiocarbon years before present (yr BP). Inland, the strongest Myrtaceae-forest and rainforest representation occurs around the mid-Holocene only to be replaced by open sclerophyll woodlands, as tree density and diversity decline in the last 3000 years. The development of continuous island freshwater swamp conditions, at the coast and inland, is similarly restricted to the late Holocene (c. 2600 yr BP) and fire, as a prominent feature in the Torres Strait environment, is also a relatively recent phenomenon. Comparisons with regional mainland Australian palynological records reveal a degree of consistency in results from Torres Strait suggesting a similarity in late Quaternary trends through Australian humid and seasonally tropical environments. A number of differences, however, are also apparent, highlighting a degree of diversity which warrants further attention.  相似文献   

14.
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.  相似文献   

15.
Aim This study aims to separate regional and local controls on Holocene vegetation development and examine how well pollen records reflect climate change in a semi‐arid region. The relative importance of climate and human activity as agents of vegetation change in the Sahel during the late Holocene is also considered. Location Jikariya Lake, an inter‐dune depression in the Manga Grasslands of north‐eastern Nigeria. Methods Pollen and charcoal were used to provide a record of Holocene vegetation history. Palaeoclimate and hydrological changes were reconstructed from sedimentary and geochemical data. Regional and local influences were separated by comparing the evidence obtained from Jikariya Lake with previously published data from the Manga Grasslands. Results The Manga Grasslands experienced a prolonged wet period during the early and mid‐Holocene, during which swamp forest vegetation with Guinean affinities (Alchornea, Syzygium, Uapaca) occupied the inter‐dune depressions. However, variation in the pollen records between sites suggests that their establishment was dependent on conditions being locally favourable, rather than being directly coupled to regional climate. The pollen records from the Manga Grasslands are more consistent in suggesting the colonization of the dunefields by trees associated with Sudanian savanna (Combretaceae, Detarium) c. 8700 cal. yr bp . The Jikariya Lake pollen data are in accordance with the sedimentological and geochemical data from the region in indicating that the onset of arid conditions occurred progressively during the late Holocene (from c. 4700 cal. yr bp ). Abrupt changes in pollen stratigraphy, recorded at other Manga Grasslands sites 3500 cal. yr bp , appear to be the product of the local passing of ecological thresholds. The dunefield vegetation (Sahelian savanna) appears to have been resilient to (or at least palynologically silent regarding) to the climatic variability of the late Holocene. Main conclusions While climate appears to have been the primary control on vegetation development in the Manga Grasslands during the Holocene, local conditions (particularly depression size and sand influx) had a strong influence on the timing of pollen stratigraphic changes. Anthropogenic influences are difficult to detect, even during the late Holocene.  相似文献   

16.
Charcoal recovered from middens and graves in the neolithic site of Kadero, north of Khartoum, Sudan was analysed. The site lies within the semi-desert vegetation zone at present. During the occupation period (5960-5030 uncal B.P.), a scrub and thorn savanna grew around the site. It is further suggested that the vegetation during the neolithic period at Kadero was already under strong human impact through controlled fires, felling and grazing.  相似文献   

17.
Recent drilling eventually reached to the base of the sediments of Lynch's Crater on the Atherton Tableland within the humid tropics of north-eastern Australia. This paper incorporates results from the sequence extension into a complete record from the site, much of which has only been presented previously in summary form. A more certain chronology for the record is provided by recent radiocarbon dating on the topmost sediments and the application of time series analysis to the whole sequence. This suggests that the vegetation and climate are forced essentially by northern hemisphere insolation and ice volume, probably operating through sea level and sea surface temperature changes. The extended record is considered to cover the last 230,000 years and the pattern of complex rainforest expansion during wetter interglacial periods and its replacement by drier rainforest and sclerophyll vegetation during drier glacials is maintained. Superimposed on this cyclicity are trends resulting from both the evolution of the lake basin as well as external influences that include climate and, within the last 45,000 years, people.  相似文献   

18.
A new pollen sequence (ca. 15,700-1250 yr BP) is presented for three stratigraphical sections of Carihuela Cave (Granada, southeastern Spain), thus completing a record that covers from the last Interglacial to late Holocene. The Late Glacial is characterized by open landscapes with junipers and early colonisation of Quercus, while the Holocene is depicted by mixed oak forests, with a diversity of broad-leaf trees and scrub, which decrease after ca. 5470 yr BP synchronously with the expansion of xerophytes and occurrence of indicators of anthropogenic disturbance. The whole pollen record of Carihuela fits into the general trends described for reference pollen sites of southern Europe, including Padul in the province of Granada, and other sequences from Mediterranean Spain, through which the heterogeneity of environmental change increases from mid to late Holocene. We conclude that, in contrast with other regions of Spain, deciduous Quercus-dominated forests are very old in eastern Andalusia, thus conflicting with floristic phytosociological models of vegetation change that imply that monospecific Q. ilex/rotundifolia woodlands are the potential mature forest in the region. Dating results suggest that the last Neanderthals of Carihuela lived between ca. 28,440 and 21,430 yr BP, which agrees with the postulation that southern Spain was the latest refugium for this human species in Europe.  相似文献   

19.
Pollen profiles, based cores taken in Lake Kahala and from the adjoining mire, were used to establish general vegetation history and to reconstruct the extent and types of land-use over most of the Holocene. Modern pollen deposition was studied using moss polsters and the results were used in the interpretation of the fossil pollen data in terms of former land-use practices. The modern-day samples are from settlements, hay meadow and pasture, and overgrown pasture. Indications of human activity can be traced back to the Stone Age. At ca. 6400 cal. B.C., the first indications of possible woodland utilisation by humans are recorded. This may have involved grazing within the forests. From 4200 cal. B.C. onwards, animal husbandry with changing intensity was practised. Arable farming, involving cereals, was introduced to the area at ca. 1800 cal. B.C., but it was only at ca. 500 cal. B.C. that it assumed an important role in the farming economy.Secale cereale (rye) was introduced during the Roman Iron Age, intensive rye cultivation started at the end of the Iron Age, at ca. cal. A.D. 800. Ever increasing farming pressures triggered the formation of openalvars. Open landscape similar to that of today has persisted, with minor forest regeneration phases, since at least 500 cal. B.C.  相似文献   

20.
A late Holocene pollen profile from the Megaris on the eastern Gulf of Corinth shows a vegetation which was strongly influenced by human impact throughout. A Pistacia-Phillyrea maquis, which is reflected in the older parts of the profile, changed later to a more degraded vegetation type. In the uppermost part Pinus dominates the pollen spectrum. A continuous record of Ceratonia siliqua pollen older than cal a.d. 100 is of special interest.  相似文献   

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