Atlantic Period Research Articles

Fossiliferous Holocene tufa of Mende (Lozère, southern France): implication for the Atlantic vegetation of the Causses Basin

AbstractTufas bearing plant macroremains are uncommon in the Causses Basin (southern France). Here, we report a new fossiliferous tufa deposits at Mende, in Lozère. This palaeontological site is the first Quaternary tufa from the northern part of the Causses Basin that yields such an abundance of plant macroremains. The radiocarbon dating shows that these Holocene deposits are related to the Atlantic period. Geomorphology and mineralogy show that the plant-bearing deposit is a calcareous tufa only composed by calcite, deposited near to an outlet of cool water, linked to the karstic hydrological system of the Causse de Mende. The flora exposed in this article is dominated by angiosperms. Leaves and reproductive structures were assigned to Acer platanoides, Corylus sp., Hedera sp., Salix cf. cinerea, and Tilia cordata. This new palaeobotanical data complements our scarcely knowledge of the Atlantic floras from the Causses Basin. During the Atlantic period, and in the northern part of the basin, whereas Pinus-dominated forests and oak groves were probably well-developed, valleys were locally inhabited by diversified wet angiosperm-dominated forests.

Composition of Atlantic forest in northern Carpathian foothills, from a charcoal record from a Neolithic domestic site at Żerków (Poland): The relevance of oak and hazel

Abstract A study of firewood remains from the foothills of the Western Carpathians in Poland yielded information about the history of forest communities growing in the vicinity of human settlements in the Atlantic period. The anthracological material was collected at Żerków, a Neolithic site of the Linear Band Pottery culture, situated on the highest parts of a hill covered by fertile soil. The anthracological assemblage was dominated by Quercus and Corylus avellana, followed by Acer and Maloideae, suggesting that those taxa probably were significant constituents of the local forest during the Atlantic period. Based on the ecological requirements of the identified taxa, such communities occupied areas of more open canopy, but it is unclear whether the material reflects the composition of the primeval forest or rather the presence of open canopy created by human impacts on local ecosystems during the period of settlement.

Paleolimnological record of the climate and pre-historic settlement from chalk karst region (Chełm Hills, SE Poland)

The multi-proxy study (subfossil Cladocera and Ostracoda, palynology, sediment chemistry, stable isotopes) of the sedimentological record from three, closely situated, shallow lakes reveals multiple interactions between the lake esosystems and the main drivers of their mid- and late-Holocene development – climate changes and human actions within their vicinity. Such multi-proxy studies, built upon four complete cores obtained from three nearby situated sites, provide us with an unique advantage/opportunity to disentangle climate and human influence, as well as to trace in detail the ecosystem response. Starting from the Atlantic period, the favourable natural conditions of the Chelm Hills region (mainly rich, workable soils) attracted early settlement more than did nearby regions. This settlement grouped with close vicinity to natural water sources: lakes and small river valleys. Despite the rather low impact of the early settlement on the natural environment, its traces can be made visible from the pollen record of lake archives, as well as from eutrophication signals revealed by subfossil Cladocera and Ostracoda. In this study, three main settlement phases were noted. Herein, hemp retting practices were identified for all the lakes. This is put forward as the most profound factor in this lake ecosystem development (resulting, among other issues, in severe anoxia) and therefore, it was studied in detail as well as the issue of its further recovery

Factors influencing temporal changes in chemical composition of biogenic deposits in the middle Tążyna River Valley (Kuyavian Lakeland, central Poland)

AbstractThe present paper discusses the influence of geochemical properties on biogenic deposits in the Wilkostowo mire near Toruń, central Poland. The analysed core has allowed the documentation of environmental changes between the older part of the Atlantic Period and the present day (probably interrupted at the turn of the Meso- and Neoholocene). In order to reconstruct the main stages in the sedimentation of biogenic deposits, we have used stratigraphic variability of selected litho-geochemical elements (organic matter, calcium carbonate, biogenic and terrigenous silica, macro- and micro-elements: Na, K, Mg, Ca, Fe, Mn, Cu, Zn, Pb, Cr and Ni). The main litho-geochemical component is CaCO3; its content ranges from 4.1 per cent to 92 per cent. The variability of CaCO3content reflects mainly changes in hydrological and geomorphological conditions within the catchment area. The effects of prehistoric anthropogenic activities in the catchment of the River Tążyna, e.g., the use of saline water for economic purposes, are recorded in a change from calcareous gyttja into detritus-calcareous gyttja sedimentation and an increased content of lithophilous elements (Na, K, Mg and Ni) in the sediments. Principal component analysis (PCA) has enabled the distinction the most important factors that affected the chemical composition of sediments at the Wilkostowo site, i.e., mechanical and chemical denudation processes in the catchment, changes in redox conditions, bioaccumulation of selected elements and human activity. Sediments of the Wilkostowo mire are located in the direct vicinity of an archaeological site, where traces of intensive settlement dating back to the Neolithic have been documented. The settlement phase is recorded both in lithology and geochemical properties of biogenic deposits which fill the reservoir formed at the bottom of the Parchania Canal Valley.

Early Holocene hydrology and environments of the Ner River (Poland)

The Ner River valley (central Poland) underwent substantial transformation during the Weichselian–Holocene transition as a result of fluvial processes and climate changes, resulting in the establishment of its present shape in the Holocene. A multiproxy study based on organic deposits from a palaeochannel fill (Lutomiersk–Koziówki) shows that after the channel was cut off during the late glacial termination, it became a shallow oxbow, fed by local springs. In the Boreal period, the oxbow lake was also fed by precipitation and became a telmatic environment overgrown by rush and swamp vegetation. Finally, it was covered by overbank deposits. The first flooding phase (9900–9600cal. BP) was followed by the accumulation of overbank sediments (after 9500cal. BP) and flooding increased after ca. 9300–9000cal. BP. Pollen data provide information on the regional vegetation context for local and regional changes. In the Atlantic period, an increase in both summer and winter temperatures is inferred from the pollen data, corresponding to an expansion of thermophilous deciduous forests. While in general, flooding phases of the Early Holocene are poorly recognised in Eastern Europe, the Lutomiersk–Koziówki site may be considered as one of the reference points for this phenomenon in the region.

Holocen history of vegetation at “Uroczysko Mokradła” (SW Poland) – paleobotanical research

Two peat bogs were studied in the Bory Dolnośląskie, the forest complex in Lower Silesia (Poland). An Instorf drill was used to collect two peat profiles from the deepest places. The macroremains analysis showed that after the initiation of peat-forming processes phytocoenoses responsible for the deposition of transition sphagnum peat were developed at both locations. Later on, the development of both peat bogs differed. The smaller peat bog continued to develop, whereas the big bog was shifted to ombrotrophic water regime. Therefore, phytocoenoses accumulated 1.3 m of <em>Sphagnum</em> peat. The peat-forming process was initiated at different times in both sites. For the smaller peat bog, it took place during the Atlantic period, while in the case of the larger peat bog – several thousand years later. The first identified forest phytocoenoses in the Atlantic period are mesophilic multi-species deciduous forests. Dry coniferous forests and mixed birch-pine forests grew in dry habitats. Riparian forests occupied lower grounds. In the Subboreal period, the oak–hazel communities initially developed and mixed coniferous forests were partially replaced by light oak forests. The encroachment of spruce, fir, hornbeam, and beech resulted in the development of dry ground forests, including beech–fir woods. The importance of riparian forests increased, whereas in dry grounds pine and mixed coniferous forests continued to occur. In the Subatlantic period, the transformations in forest communities were associated with the spread of hornbeam, beech, and fir and thereby vast fertile habitats were colonized by dry ground communities and beech woods. Pine and mixed forests as well as riparian forests were of lesser importance. Pollen records from the last 500 years showed the clear presence of humans. It was evident from the presence of cereal and weed pollen and from the disturbances in the pollen records caused by peat extraction in the Middle Ages.

The Origin and Development of the Central European Man-made Landscape, Habitat and Species Diversity as Affected by Climate and its Changes – a Review

The Origin and Development of the Central European Man-made Landscape, Habitat and Species Diversity as Affected by Climate and its Changes – a Review

Reconstruction of palaeoecological changes in Lake Łebsko on the basis diatom analysis (the southern Baltic coast, Poland)

This study focuses on diatom assemblages occurring in core Łeb1 of Late-glacial and Holocene deposits from Lake Łebsko, off the southern coast of the Baltic Sea. Diatom-inferred environmental characteristics, e.g., water level, water salinity (conductivity), trophic status and pH, from the Holocene are presented. In the sediments from the early Boreal/early Atlantic period, an increase in the participation of brackish-freshwater species is observed, as well as increased numbers of Chaetoceros spores in the samples. The Atlantic sediments of Lake Łebsko mirror conditions typical of the Littorina Sea phase during the development of the Baltic Sea (from c. 7,500 BP to c. 5,000 BP). However, communities of that period dominated by fresh-brackish water species suggest the relatively low salinity of the waters. The presence of isolated frustules of Terpsinoe americana and other typically marine species, e.g., Mastogloia smithii, and the occurrence of silts with Cardium shell detritus point to the Littorina transgression and the functioning of a lagoon within the area of present-day Lake Łebsko. During Subboreal occurrence, a higher number of brackish-freshwater diatoms corresponds to an increase in the water level of the Baltic Sea (approximately 3,000 14C BP). Changes in diatom community structure imply a close relationship with the climate controlled eustatic rise of ocean level and the consequent Littorina transgression, as with other southern Baltic Sea localities.

The 8200 calBP climate event and the spread of the Neolithic in Eastern Europe

At 8200 calBP, the beginning of the Atlantic period, there was a drastic change from warm and humid climatic conditions to cold conditions. The abrupt cooling at 8200 calBP has been documented in different parts of Europe. In western, and some parts of southern, Europe, this event was a trigger for new forms of economy and migrations of groups of Neolithic farmers. This paper considers the different ways in which ceramic traditions developed in eastern Europe in the steppe,steppe-forest and forest zones as a result of the rapid climate changes at about 8200 calBP.

Natural transformation of the Romoty paleolake (NE Poland) during the Late Glacial and Holocene based on isotopic, pollen, cladoceran and geochemical data

“Romoty” is the name of a sediment profile from the overgrown lake located in Ełk Lakeland (NE Poland). The sediment core, which is 8.4 m in length, documents the development of the reservoir since the melting of dead ice and formation of the lake basin, i.e., before 13,000 years BP, until it became overgrown with plants. The characteristics of the sediments changed from mineral deposits on the bottom (silty sands) to biogenic deposits consisting of dark olive calcareous detritus gyttja and light calcareous gyttja with increasing carbonate content and to peat in the upper part.Based on the data (chemical, stable isotopes, subfossil Cladocera remains, pollen), we have distinguished three main stages of the evolution of Romoty paleolake. The first stage includes the formation of the lake basin in the Late Glacial and early Holocene (Preboreal). The second stage is characterized by the harmonic, natural development of the Romoty paleolake from the Boreal to Subboreal. This stage coincides with a period of climatic warming, and biogenic sediments accumulated in this reservoir at that time. The third stage concerns the disappearance of the lake in the late Holocene (Subatlantic). The lake conditions declined, and the reservoir completely filled with sediments and has transformed into a mire. The characterization of each stage involves a description of environmental conditions occurring in the Romoty paleolake, particularly the Cladocera community, the chemical composition, the temperature and trophy of the water, the water level, the nature of bottom sediments, and the plants occurring in the reservoir and its surroundings.The lowest water temperature occurred in the Late Glacial and Preboreal periods. Since the Boreal period, gradual warming is observed and is expressed through a positive trend in both δ18O and δ13C and changes in both Cladocera and plant compositions. The lake was deepest at the beginning of the Holocene as a result of dead ice melting (supply of melt water; lowering of the lake bottom) and/or increased precipitation (change in atmospheric circulation). The water level fell during the Atlantic period. Additionally, the cladoceran and non-pollen palynomorph data indicate low trophy followed by an increase in the mesotrophic state. Human impact was documented only by a low occurrence of pollen grains of Cerealia in the youngest sediments (Subatlantic period), suggesting a low penetration by human groups of the area near the Romoty paleolake.

Modern changes of the high-mountain landscapes and glaciation in Southern Siberia (Russia) by the example of the Eastern Sayan mountains

The period of observations of glaciation of the Munku-Sardyk mountain massif in Siberia is one of the longest, i.e. 155 years. However, the data obtained are scattered and not systematic. The paper presents an integrated analysis of the materials collected since the first description by the explorer of Siberian mountains G.I. Radde Istoriy (1896) and extended by Peretolchin (1908) and Komarov (1953), as well as by glaciologists Maksimov (1965), Arefiev and Mukhametov (1996). The authors considered the current state of the glaciers and interaction of natural geosystems of the massif taking into account the nival-glacial processes. Since the beginning of the current millennium, regular observations have been conducted on the Munku-Sardyk massif by the V.B. Sochava Institute of Geography SB RAS, Limnological Institute SB RAS, and East-Siberian State Academy of Education. The studies revealed the leading landscape-forming factors and examined the landscape structure of the surroundings of the contemporary nival-glacial geosystems with due regard for the manifestations of altitudinal zonation. A medium-scale landscape-typological mapping was carried out. Presented are the quantitative parameters of the dynamics of the nival-glacial geosystems obtained on the basis of modern remote sensing instruments, GPS measurements and surface laser scanning using GIS analysis. The stump and stem of larch detected in the valley of the Bugovek River 300 m above the contemporary upper forest limit and 1330 m up the valley show that most likely there was no glaciation during the Atlantic period (7000–7300 years ago). The modern glacier complex has formed only during the last 4000–5000 years. The trend of shrinkage of glaciers since the end of the Little Ice Age can be traced, especially in recent years. The length and area of the open part of the glaciers have decreased by half (from 0.68 to 0.34 km2). The presence of small forms of glaciation on the southernmost limit of the Siberian glaciation 1500 m below the theoretical (climate) boundary suggests that this area can be considered a unique key site to identify trends in development of the mountain and nival-glacial geosystems, and provides an opportunity to built reconstructive and predictive models of development of mountain landscapes under the conditions of ever-increasing anthropogenic influence.

PALEOGEOGRAPHY OF THE ZAONEZHYE PENINSULA IN THE LATE PLEISTOCENE AND HOLOCENE

The paper summarizes the results of long-term paleogeographical research of the Zaonezhye Peninsula conducted by the staff of the Institute of Biology and Institute of Geology of the Karelian Research Centre RAS, including the authors of the article. The history of landscape and Quaternary deposits evolution, vegetation dynamics affected by climate change, deglaciation and transgression-regression cycles of Lake Onega during the Late Glacial and Holocene are analyzed. Global warming in the Holocene caused a gradual change of the Late Glacial periglacial-steppe and tundra communities with light birch forest-tundra. Birch and pine-birch light northern taiga forests appeared around 9600 BP. Middle-taiga pine forests reached their distribution maximum around 8900-8000 BP. Temperature rise and increasing humidity in the Atlantic period contributed to the distribution of Ulmus, Quercus, Tilia, Acer, Corylus and Alnus glutinosa especially in the interval between 7000 and 6000 BP (6580 ± 80 BP, LU-3422) resulting in the southern taiga vegetation. Spruce forests expanded along with pine and pine-birch forests and became dominant especially in the second half of the Subboreal. Southern taiga forest types are preserved to the present day on the Zaonezhye Peninsula; secondary forests arisen from intensive human activities are also diverse. Based on the obtained data some assumptions on the possible location of settlements in different periods of the Holocene are made. It is established that agriculture in the territory began around 1100-900 BP (1140 ± 50 BP, LE-6531; 950 ± 110 BP, LE-6796).

New pedoanthracological data for the long-term history of forest species at mid-high altitudes in the Queyras Valley (Inner Alps)

In the context of global change, the assessment of the past history and current dynamics of forest species is essential for improving our knowledge of the settlement and evolution of the present-day landscape. Several paleoecological approaches are well suited for reconstructing past landscapes and Holocene dynamics. Today, the subalpine forest of Queyras is composed primarily of larch, with lesser proportions of stone pine, mountain pine and fir. During the Holocene, the subalpine forest was subject to natural disturbances, particularly fires. By the end of the Atlantic period, human perturbations resulting from agro-sylvo-pastoral practices became an important factor, and this factor serves to explain the landscape dynamics and the dominance of certain woody species. In this study, a pedoanthracological approach was used to enhance existing knowledge of the history of forest species and to reach a good understanding of the processes that have shaped the current floristic assemblage.The results of the analyses of soil charcoal performed in this study provide the following new information: (i) a longer Holocene history for larch and stone pine, (ii) a lack of evidence for a natural presence of fir and (iii) a long-term history for Scots pine. The dates obtained reveal the early occurrence of recolonization by stone pine and larch following the last glaciation. The charcoals analyzed demonstrate the overall presence of stone pine, which is found throughout the studied history of the area. In terms of the changes presently occurring, among which both the abandonment of human land-use practices and climate change are especially important, the current conditions at mid-high altitudes might potentially allow the establishment of larch forests for a long period as preclimax ecosystems. The low frequency of fir in charcoal samples raises questions about the status and possible presence of fir in the past despite palynological evidence.

Evolution of landscapes of the Moskva River floodplain in the Atlantic and Subboreal: Pedological and palynological records

Floodplain deposits in the valley of the Moskva River contain a series of buried soils of the Holocene age, which can be an important source of paleoecological information. These soils were dated as follows: Soil 1 — 100BP, Soil 2 — cal 1200AD–500BC, Soil 3 — 900–2700BC, and Soil 4 — 3700–6000BC. Archeological monuments associated with these soils belong to the Neolithic (Soil 4), Early Bronze Age (Soil 3), and Iron Age and Middle Ages (Soil 2). Buried soils have well developed profiles and diagnostic features. Dark-colored soils of the Atlantic period (Soil 4) in most cases can be attributed to Phaeozems. Pollen analysis shows that these soils were formed under forest-steppe communities. Buried soils of the Subatlantic period (Soil 2) are usually referred to as Luvisols. Unlike them, the soils of the Subboreal period (Soil 3) are traced in rare cases and have no clear diagnostic features allowing reconstruction of the paleoenvironment. These soils have a light-colored humus horizon, which does not allow them to be classified as Phaeozems. However, they do not have the Bt horizon characteristic of Luvisols. This paper describes the results of a new comprehensive study of the Moskva River floodplain near the Zvenigorod Biological Station (ZBS) of Moscow State University. The buried soils of the Atlantic and Subboreal periods were studied by palaeopedological and palynological methods. The findings confirmed previously obtained results and indicated that the buried Soil 3 at the ZBS site could be developed under mixed forests dominated by spruce. These results suggest that the landscapes of the lower levels of the valley changed dramatically between 5000 and 4500calBP. The forest-steppe communities were replaced by dense forests due to the early Subboreal climate change. The paper also examines the specifics of soil and pollen records of the landscape evolution. The anthropogenic influence on the floodplain landscapes is also considered.

Holocene Vegetation and Climate History of the Cheshskaya Bay Region, SE Barents Sea, Inferred from the First Pollen Archives

First high-resolution micropaleontologic investigation was carried out for bottom sediments of the Cheshskaya Bay (SE Barents Sea) and marine beds exposed in abrasive terrace along the eastern coast of the Kanin Peninsula. Sediments from 2 gravity cores and a 7.5-m thick terrace section were analyzed for pollen and non-pollen palynomorphs (NPP), including spores, freshwater green algae and cysts of marine dinoflagellates. The age of the sediments was constrained by the reference to the regional sea-level history from the earliest Holocene to present, thus the pollen records reveal the environmental history for the last ca. 10.0 ka. Sparse treeless vegetation with dwarf Betula and halophytic inhabitants of seaside watts (cereals, wormwood and sedges) indicating arctic desert environment with colder and drier than present climate dominated the Cheshskaya Bay coast during the early Preboreal period. Gradual advance of shrubby-birch and piny forest-tundra with alder communities along river valleys resulted from significant climate amelioration which concurred with the Pholas inundation since the Boreal period. Postdated expansion of tree-birch inland the Kanin Peninsula and firry-birch light-forests along the Cheshskaya Bay coast marked the Holocene regional climate optimum. Re-establishment of the dwarf-birch and piny forest tundra signalized vegetation feedback to the cooling since the end of Atlantic period.

STEPPE AND FOREST-STEPPE VOLGA REGIONS IN THE EARLY NEOLITHIC PERIOD: THE PROBLEM OF CONTACTS

According to the radiocarbon chronology formation of the Neolithic communities acquainted with manufacturing baked clay pottery takes place in the Steppe and Forest-steppe Volga region in the early Atlantic period about 6000 BC. Weakly ornamented Yelshanka point-bottomed pottery borrowed from Transurals was developing in the Forest-steppe Volga region at this period. As for the Steppe Volga region, plain-bottomed richly ornamented Cairshak pottery influenced by the traditions of the Transcaucasus Neolithic centers was spreading. Establishing close contact between Steppe and Forest-steppe Volga regions population dates as far back as the last quarter of the 6 th millennium BC which caused extrinsic for the Asiatic region features of the Yelshanka pottery such as smoothed body rib, crown bulge, geometrized ornament of drawn lines and dimples forming triangles, punctured zigzags. In the early 5 th millennium BC latitudinal contacts tended to substitute longitudinal ones which is proved by differences having appeared between the Steppe and Forest-steppe Volga region pottery. Tradition of producing ribbed vessels with crown bulge continued in the steppe was lost in the forest-steppe. Distribution of the non-ornamented plain-bottomed pottery of the Lugovskoy type in the Middle-Volga area also confirms the fact of developing latitudinal contacts. There is no such pottery in the Steppe Volga region but it can be found in numerous cultures south of the Russian Plain. As the most ancient sets of such pottery were found in the Bugo-Dnestr culture so it could be supposed that its dispersion beyond the original territory happened under the eastward pressure of the Tripolye culture. External character of the non-ornamented plain-bottomed pottery of the Lugovskoy type is proved by its typological heterogeneity. Vessels with body rib and crown bulge are characteristic for some of the pottery sets with sporadic ones having dimple-pearly girdle (e.g. Ust-Tashelka). In other sets the number of vessels with dimple-pearly girdles is much bigger while there are much less vessels with body rib and crown bulge (e.g. Krasny Gorodok, Lugovoye III) which reflects the process of assimilating the new-comers by the descendants of the Yelshanka culture.

Palynological investigations at the Late Bronze–Early Iron Age lakeshore settlement of Luokesa 1 (Moletai District, Lithuania): a contribution to the Middle-Late Holocene vegetation history of the south-eastern Baltic regions

Today, the settlement site of Luokesa 1 (L1) lies under water at the northern edge of Lake Luokesa in the Baltic Uplands, south-eastern Lithuania. Its 60 cm-thick Late Bronze–Early Iron Age cultural layer lies on top of lake marl. During excavations in 2008 and 2009, core samples at L1 were taken for the purpose of multidisciplinary investigations. From this material, five on-site pollen diagrams were created in parallel with geo-archaeological investigations and the examination of the botanical macro-remains. Two of these cores mainly comprised the cultural layer, another two consisted largely of the underlying lake marl and the fifth contained primarily the transition from the lake marl to the cultural layer. The chronological sequence was established through 11 AMS dates. The woodland history, starting from the Late Atlantic period, was recorded. The Quercetum mixtum values are quite low in the Subboreal, with the coniferous forest consisting mainly of Pinus and, though significantly less, Picea. At the transition to the cultural layer (Subatlantic) the pollen curves are highly variable, showing peaks in the curves for Betula and Alnus. Pollen from aquatic plants is also present. Changes in riparian vegetation and turbulent sedimentation conditions are to be expected and can be explained by a drop in the water level. As L1 was located on damp ground at that time, water influxes alternating with dry episodes were observed. In the area around L1 the sedge belt was less pronounced, and riparian woodland extended all the way to the shores of the lake. Pollen analyses of four sheep/goat dung samples provide information on the grazing season and pasture location of these domestic animals. The paper also discusses layer formation processes such as water level fluctuations and hiatuses.

Paleosols, paleovegetation and Neolithic occupation of the Moskva River floodplain, Central Russia

This article describes the results of a comprehensive study of the first Zvenigorod Neolithic site, the cultural layer of which lies in the buried soil of the Moskva River floodplain. The soil dates to the late 5th – beginning of the 4th millennium BC. Pedological methods placed this soil in the Chernozem soil group, which is markedly different from modern Fluvisols and Albeluvisols. Similar Chernozem soil, dated 5000–3500 cal BC, has been found previously in other sites of the Moskva River valley. Pollen analysis of the buried soil showed that in the second half of the Atlantic period the vegetation of the floodplain consisted of meadow-steppe and broad-leaved forest elements. This vegetation is notably different from the vegetation of the late Holocene, which consisted mostly of spruce-deciduous forests. Archaeological and radiocarbon data indicate that this Neolithic site was a long-term settlement. Some traces of human impact on the vegetation of the Neolithic were revealed. The potential nature of the economy of Neolithic settlements in Moscow area is discussed.

Postglacial occurrence and decline ofBetula nanaL. (dwarf birch) in northeastern Poland

The Late Glacial and Holocene presence of Betula nana L. (dwarf birch) in northeastern Poland was reconstructed through palaeoecological analyses of sediment cores from the Taboly mire located in the territory of the Knyszynska Forest. Peat records spanning thousands of years were analysed for plant macrofossils along with radiocarbon dating. Betula nana was present in Taboly from ca 13 000 to ca 9000 yr BP. The presence of this species was described in the Late Glacial period, most likely in the Allerod and Younger Dryas. However, our research on the palaeoecology of dwarf birch showed that after the Late Glacial/Holocene transition, the species did not disappear from northeastern Poland and still existed in the Preboreal, Boreal and lower Atlantic periods. The occurrence of Betula nana was documented by the presence of generative remains (nuts and catkin scales) in sediments, which is the best evidence of its in situ position. The later disappearance of the studied species could be related to the negative effects of palaeoenvironmental conditions in the Atlantic, which resulted in a temperature increase and high precipitation, causing the waterlogging of the substratum and rendering it unsuitable for dwarf shrub that prefers severe climate conditions. The Taboly site seems to be one of separate locations of B. nana during the Atlantic in this part of Europe.

Cladocera record from Budzewo (Skaliska Basin, north-eastern Poland)

ABSTRACT The sediment sequence from Budzewo (Skaliska Basin, north-eastern Poland) contains cladoceran records beginning from the early Holocene. A total of 33 Cladocera taxa were identified in the entire sequence. The cladoceran fauna of the initial stage of palaeolake history in the Preboreal shows high similarity to early Holocene Estonian and Scandinavian records. Benthic Alonella nana was dominant at that time. After that, probably during the Boreal and early Atlantic periods, Cladocera species diversity increased and planktonic forms (bosminas) became dominant, pointing to a rise of water level. The species composition indicates that the lake was meso- to eutrophic. The lake began to shallow during the middle Atlantic. The process was completed in the Subboreal and the lake transformed into a bog. The fall in water level and finally the terrestrialization of the lake is correlated with similar processes recorded in other sediment sequences in northern Poland, suggesting that this event may have been driven by regional factors such as lower precipitation.