Elena G. Lapteva

In modern paleoecological research, subrecent (modern or near-modern) data are the basis for constructing calibration models that allow us to interpret the fossil records. Therefore, it is important to understand how accurately subrecent data reflect the composition and structure of modern plant communities, especially in areas where vegetation distribution is highly dependent on topography, local microclimate, and regional climatic parameters. The article presents the results of a comprehensive study into the composition of 17 surface samples collected in plant communities of the Malozemelskaya tundra within the vicinity of Lake Golodnaya Guba. Surface samples were collected from both typical zonal shrub/dwarf-shrub moss tundra and extra-zonal spruce and birch forest areas that are atypical for tundra. The samples were studied using pollen and plant macrofossil analyses. Our data show that the subrecent pollen spectra and macro-remain complexes as a whole reliably reflect the composition of shrub tundra plant communities, characterizing the zonal and local components. However, the degree of participation of individual plant species does not always correspond to their role in communities. The subrecent pollen spectra and macro-remain complexes of the extrazonal forest stands are similar to those of the forest-tundra, reflecting the forest type of vegetation. Spruce and birch pollen does not show a significant deformation on zonal subrecent pollen spectra. Macrofossils of these tree species were found only sporadically outside extrazonal forest areas. The presence of pine pollen, as a long-distance component, does not have a significant effect on the subrecent spectra. Macro-remains of pine were not found in subrecent complexes. The adequacy of subrecent pollen spectra and macro-remain complexes to plant communities is confirmed by cluster analysis, according to which the most statistically similar spectra and complexes are formed in phytocenoses with similar floral composition. The revealed patterns and features of plant communities composition as reflected in subrecent spectra and complexes will enable more accurate paleo-ecological reconstructions within the Malozemelskaya tundra based on pollen and plant macrofossil analyses.

A comprehensive paleoecological study of permafrost peat deposits from three locations in the middle reaches of the Yuribei River in the subzone of modern subarctic shrub tundra of the Yamal Peninsula has been performed. Based on the results of palynological and carpological methods and of radiocarbon dating, the changes in regional and local vegetation and climatic conditions of Central Yamal in the Late Glacial and the Postglacial periods are reconstructed. It is found that shrubby tundra with Betula nana was widespread in this area under climatic conditions close to modern ones in the Younger Dryas about 12.6–11.7 cal ka BP. The penetration of tree species (Betula sect. Betula, Picea obovata, and Larix sibirica) and accompanying boreal herbaceous plants began due to more favorable climatic conditions during the Early Holocene warming about 10.2–9.7 cal ka BP. The most favorable conditions for the growth of birch tree, larch, and spruce existed in Central Yamal in the Early and the Middle Holocene in the range of 10.2–4.4 cal ka BP. At that time, open woodlands or even closed forests were common, and the climate was much warmer than the modern one. Forest vegetation degraded and open landscapes with tundra communities were formed at the end of the Middle Holocene (4.5–4.4 cal ka BP). The climatic conditions became similar to modern ones.

Динамика природной среды Верхнего Прикамья в голоцене по материалам изучения болот

An Archaeobotanical Study of the Bukhta Nakhodka Fort, the Yamal Peninsula (13th to Early 14th Century)

The paper presents new paleobotanical data in combination with the results of radiocarbon dating obtained from organomineral deposits of the northern shore of Lake. Pechevalavato (70°13’22.3” N, 71°50’57.6” E) in the Seyakha river basin and characterizing the dynamics of vegetation in the northern part of Central Yamal in the Holocene. It has been established that in the Early Holocene (10.2–8.7 thousand years ago) in Yamal, tree-shaped birch (Betula sect. Betula) grew no less than 400 km north of the modern northern limit of distribution of Betula pubescens ssp. tortuosa. Favorable conditions for the existence of birch woodlands at this time were due to the higher temperature of the growing season, exceeding by approximately 3–4 °C the modern parameters of the warmest month of the summer season. At the end of the Early Holocene (after 8.5 thousand cal BP), forest vegetation began to degrade, and open landscapes with diverse plant communities of the subarctic tundra and single trees in the river valley spread. About 6.5 thousand cal BP the northern subarctic tundra began to form the zonal appearance of the study area in climatic conditions close to modern ones.

The paper presents new paleobotanical data in combination with the results of radiocarbon dating obtained from organomineral deposits of the northern shore of Pechevalavato Lake (70°13′22.3″ N, 71°50′57.6″ E) in the Seyakha River basin and characterizing the dynamics of vegetation in the northern part of Central Yamal in the Holocene. It has been shown that a tree birch (Betula sect. Betula) grew in Yamal in the early Holocene (10.2–8.7 cal kyr BP) no less than 400 km north of the modern northern limit of distribution of Betula pubescens ssp. tortuosa. Favorable conditions for the existence of birch woodlands at this time were provided by a higher temperature of the growing season, exceeding the modern parameters of the warmest month of the summer season by approximately 3–4°C. At the end of the early Holocene (after 8.5 cal kyr BP), forest vegetation began to degrade, and open landscapes with diverse plant communities of the subarctic tundra and single trees in the river valley spread. About 6.5 cal kyr BP, the northern subarctic tundra began to form the zonal appearance of the study area in climatic conditions close to modern ones.

We have performed a comprehensive paleoecological study of the peat bog deposits from six localities of the Seyakha, Yuribey and Khadytayakha rivers in the subarctic tundra zone on the Yamal Peninsula. Radiocarbon dating, as well as pollen and plant macrofossil analyses were used to track the chronological changes of the plant communities on the peninsula along the North-South transect in the Late Glacial and Postglacial periods. It was found that open woodland with tree birch and spruce existed in the Yuribey river valley during the Bölling-Allerød interstadial (between 14.7 and 12.7 cal. ka BP). Shrub tundra with Betula nana was widespread in this area during the Younger Dryas, between 12.6 and 11.7 cal. ka BP, under climatic conditions similar to modern ones. The spread of arboreal species (Betula sect. Betula, Picea obovata, Larix sibirica) and associated boreal herbaceous plants began later (between 10.2 and 9.7 cal. ka BP) as climatic conditions improved. The most favorable conditions for tree birch and larch existed in the Seyakha river valley between 10.2 and 8.7 cal. ka BP, whereas the best conditions for the same species and spruce in the Yuribey river valley were observed between 10.2 and 4.4 cal. ka BP. It was much warmer than it is today, and open woodland or even closed forests were widespread. Forest degradation and spread of open landscapes with tundra communities occurred in the Seyakha river valley after 8.7–8.5 cal. ka BP and in the Yuribey river valley after 4.7–4.3 cal. ka BP. Climatic conditions became similar to modern ones. Today, arboreal species grow in the Khadytayakha river valley, forming extrazonal forest communities in the subarctic tundra zones.

This paper provides the first paleolimnological studies performed in the upper Kama basin (Perm region). These yielded a detailed pollen record characterizing the changes in the natural conditions of the transition from the periglacial environment of the Late Glacial period to the interglacial conditions of the Holocene between 14.15 and 10.0 cal ka BP. It was found that open birch woodland with larch existed in the Allerød period (14.15–12.7 сal ka BP) and was replaced by larch forest-steppe during the Younger Dryas (12.7–11.5 cal ka BP). The spread of spruce began in the early Holocene between 11.5 and 10.7 cal ka BP, whereas open larch and spruce woodlands became dominant between 10.7 and 10.0 cal ka BP. Quantitative palaeoclimatic reconstruction reveals that the average temperature of the warmest month (July) and the annual precipitation were considerably lower than modern values. The average July temperature increased from 10 to 16ºС between 14.15 and 12.7 cal ka BP. Then, small fluctuations within 1ºС occurred between 12.7 and 10.0 cal ka BP. The average annual precipitation was 200-300 mm below modern values between 14.15 and 10.7 cal ka BP and reached them only after 10.7 cal ka BP.

В статье рассматриваются результаты комплексного археоботанического изучения серии образцов из культурного слоя городища Бухта Находка (XIII — начало XIV в. н.э.) на п-ове Ямал Западной Сибири. На основе детального анализа таксономического разнообразия микро- и макроостатков растений реконструированы существовавшие в то время в окрестностях поселения травяно-мохово-кустарничковые тундры. Обилие пыльцевых зерен и остатков вегетативных частей растений в культурном слое внутри построек подтвердило ранее сделанное по материалам раскопок предположение об использовании при их строительстве торфо-дерновых брикетов, которые получали при снятии слоя дерна. Выявлена трансформация растительного покрова тундр на территории городища и в непосредственной близости от него: нарушение целостности почвенного покрова в период строительства городка; активное расселение тундровых рудеральных растений-апофитов и частичное восстановление дернового слоя во время функционирования поселения; формирование вторичного задернованного напочвенного покрова, отличающегося от естественных тундровых сообществ, после прекращения функционирования. Найдены остатки дикорастущих пищевых растений, а культурных — не обнаружены. На основе комплексных археоботанических данных установлено, что растительные ресурсы субарктических тундр п-ова Ямал доненецкое аборигенное население использовало преимущественно как строительный материал в бытовом хозяйстве и, вероятно, в своем пищевом рационе.

The work presents the results of archaeological and paleobotanical studies of samples of the cultural layer and associated soils from the identified cultural heritage site Syroy Agan 24 settlement, which is located in the extreme soil and climatic conditions of the middle taiga of Western Siberia, aimed at assessing the possibility of using spore-pollen analysis with the purpose of selecting the main anthropogenic bioindicators to study the characteristics of the economic activity of an ancient person of the Early Iron Age (mid-second half of the 1st millennium BC) and determining the exact boundaries of the cultural layer. The specifics of the formation of pollen spectra in the cultural layer is considered in detail. It is established that signs of anthropogenic impact on landscape changes are recorded by the spore-pollen method. Anthropogenic bioindicators are identified. It is suggested that the use of anthropogenic bioindicators will make it possible to accurately determine the boundaries of the cultural layer, which will contribute to the preservation of cultural heritage.