NE Poland Research Articles

Anthracological analysis of wooden shaft remains from the Roman‐period sacrificial lake of Nidajno, Czaszkowo 1 site, north‐eastern Poland

AbstractHere, we report on an archaeobotanical study of charred wood remains from eight iron spearhead sockets from a sacrificial aquatic site at Nidajno/Czaszkowo 1, Mazurian Lakeland, NE Poland (c. second–fifth c. CE), in search of botanical evidence for the selection of wood for manufacture of wooden shafts used with iron spearheads. The samples were analysed using a Nicon Eclipse ME600 metallographic microscope. The results show significant botanical data for Fraxinus excelsior L. and Tillia sp.The results of this research illustrate the material standard of the finds from a unique sacrificial site of the Scandinavian ‘sacrificial bog’ type, such as the sacrificial site at Nidajno/Czaszkowo 1—one of the most scientifically prospective in the entire zone of the North European Barbaricum. They also reveal a clear preference in the way spears and javelins were made, linked to the use of ash wood for this purpose. This choice is rational, justified by the technological and operational properties of this type of wood, but it also has connotations from the world of symbolic religious imagery.

Developing a European aquatic macrophyte transfer function for reconstructing past lake-water chemistry

Quantitative paleoecological reconstructions using biological proxies, such as diatoms, Cladocera, and chironomids, have revolutionized paleolimnology and have greatly contributed to the understanding of the past local and regional environmental changes, as well as to nature conservation. While macrophytes are good ecological indicators, they have rarely been used to reconstruct past lake-water chemistry. The present study investigates which environmental variable best explains aquatic plant community composition in Finnish, Polish, and Swedish lakes for its further use in quantitative paleoenvironmental reconstructions. The method involved the creation of a modern macrophyte-environment calibration dataset, calculation of modern calibration functions using simple averaging regression, and final reconstruction of past environmental conditions in Lake Linówek (NE Poland) from a fossil assemblage using weighted averaging calibration. The data demonstrate that conductivity and alkalinity best explained macrophyte community composition in our dataset. Species “optima” for alkalinity were influenced by the presence/absence of carbon concentrating mechanisms (CCMs), enabling the utilization of HCO3− as a carbon source. Quantitative paleoenvironmental reconstruction indicates that past water conductivity and alkalinity fluctuated depending on internal lake processes and the supply of basic ions to the lake from the catchment related to climate and soil development in the watershed during the late Glacial (∼14,500–11,700 calibrated years before the present; cal BP) and the Holocene (11,700 cal BP–recent). We conclude that macrophytes can be successfully used for past lake-water chemistry reconstruction. Furthermore, calculated modern calibration functions for conductivity and alkalinity can be used in nature conservation for determining habitat requirements of numerous endangered macrophyte species as a basis for successful (re)introductions.

Influence of Hydrological and Climatic Changes on Tree Growth in Narew National Park, NE Poland, over the Past 50 Years

Over the last 50 years, groundwater levels have been decreasing and air temperatures have been increasing in Poland. Maintaining this trend may make it impossible to maintain hydrogenic habitats in good condition. Reactions to ongoing climate change recorded in tree rings may be a good indicator describing the degree of this threat. The aim of this study was to determine the influence of climatic and hydrological changes on the growth of scotch pine (Pinus sylvestris L.) and black alder (Alnus glutinosa (L.) Gaertn) in the Narew National Park over past 50 years. The research was based on tree increment cores extracted from 42 pine trees and 57 alder trees that were randomly selected and ranged in age from 25 to 88 years, as well as climatic and hydrological data. Standardised data (5-year index) were analysed by species, generation (Y—21–40 years, M—41–60, O—61–90), and decade using correlation analysis. The results of the study show that pine responded more strongly to changes in air temperature and changes in precipitation totals, while alder growth was more strongly related to fluctuations in the water level of the Narew River and changes in precipitation totals. Our research showed that differences in response to environmental factors also occur between tree generations. The decrease in the water level of the Narew River that occurred over the last 50 years did not adversely affect the condition of the trees. Analysis of DBH growth rates showed that the younger generations (Y, M) grow faster than the older generation (O). This is positive news for managers of commercial and protected forests, but accelerated tree growth may be associated with specific consequences, such as increased wind damage as a result of reduced wood density or reduced sensitivity of trees to climate and hydrological changes.

Petrogenesis of microgranular enclaves in the A-type granitoid Krasnopol intrusion (Mazury Complex, northeastern Poland): Evidence of magma mixing

The origin of magmatic microgranular enclaves has been investigated in the Mesoproterozoic granitoid Krasnopol intrusion (1.5 Ga), part of the AMCG (anorthosite–mangerite–charnockite–granite) Mazury Complex in the East European Craton (NE Poland). The granitoids are ferroan and metaluminous, and display the typical characteristics of A-type granites, with high contents of Zr, Nb, Ga and rare earth elements (REEs). The enclaves are metaluminous and have a broad compositional range with two groups distinguished: silica-poor (45–50 wt% SiO2) and silica-rich (54 to 59 wt% SiO2), the latter overlapping in composition with the granitoid samples. The silica-poor enclaves are enriched in REEs compared to the silica-rich type, while the silica-rich enclaves exhibit trace-element patterns similar to those of the granitoids. Initial whole rock εNd values range between -3.8 and -4.0 for the granitoids and give a slightly wider range from -2.6 to -3.8 for the enclaves. The 87Sr/86Sr initial values vary from 0.7084 to 0.7138 for the granitoids and between 0.7052 and 0.7075 for the enclaves and indicate that the granitoids and enclaves are not isotopically identical. These may suggest that the two magmatic systems represented by the granitoid host rock and the enclaves, were probably derived from different sources, but with sufficient interaction, which led to a progressive change in the composition of the enclaves towards intermediate composition. We suggest that the mafic melts of the enclaves were generated at the base of the thickened crust through partial melting of the lower crustal source, with a significant contribution from mantle material. The increase in temperature resulted in anatexis of the lower crust and the formation of the granitoid parental magma.

Peat formation potential of temperate fens increases with hydrological stability

Peat formation is the key process responsible for carbon sequestration in peatlands. In rich fens, peat is formed by brown mosses and belowground biomass of vascular plants. However, the impact of ecohydrological settings on the contribution of mosses and belowground biomass to peat formation remains an open question. We established seven transects in well-preserved fens in NE Poland along an ecohydrological gradient from mesotrophic sedge-moss communities with stable water levels, to more eutrophic tall sedge communities with higher water level fluctuations. In each transect, we measured the production of brown mosses (using the plug method), aboveground vascular plant biomass (one year after cutting) and belowground biomass (using ingrowth cores). Decomposition rates of all biomass fractions were assessed using litter bags. The first-year surplus of potentially peat-forming fractions, i.e., mosses and belowground biomass, decreased with increasing water level fluctuations and along a vegetation gradient from sedge-moss to tall sedge communities. Moss production was highest in the sedge-moss fen with a stable water level at the ground surface. We did not detect any difference in belowground biomass production across the gradient but found it to be consistently higher in the upper 0–5 cm than in the deeper layers. The decomposition rate also showed no response to the gradient, but differed between biomass types, with aboveground biomass of vascular plants decomposing 2.5 times faster than belowground biomass and mosses. Pattern of peat formation potential along the ecohydrological gradient in rich fen was strongly driven by brown moss production. Sedge-moss fens with a stable water level at the ground surface have the highest peat formation capacity compared to other vegetation types. In the part of the gradient that is poorer in nutrients, vascular plants invest in belowground production, and mosses dominate the aboveground layer.

Large-scale bedforms in the vicinity of Serwy Lake (NE Poland): their morphometry and links to the high-energy glaciofluvial environment

Large-scale bedforms in the vicinity of Serwy Lake (NE Poland): their morphometry and links to the high-energy glaciofluvial environment

Air pollution in Białowieża forest: Analysis of short-term trends from 2014 to 2021

Air pollution caused by sulphur dioxide (SO2) and nitrogen oxides (NOx) has negative impacts on forest health and can initiate forest dieback. Long-term monitoring and analysis of these pollution are carried out in Białowieża Forest in NE Poland due to the threats from abiotic, biotic and anthropogenic factors. The main objective of our study was to monitor the levels and trends of air pollutant deposition in Białowieża Forest. During a short-term monitoring period over six years (2014–2021), the concentration of SO2 in the air decreased significantly (from 2.03 μg m−3 in December 2015 to 0.20 μg m−3 in July 2016), while the concentration of NO2 in the air showed a non-significant decrease (from 8.24 μg m−3 in December 2015 to 1.61 μg m−3 May 2016). There was no significant linear trend in the wet deposition of S–SO4 anions. Mean monthly S–SO4 deposition varies between 4.54 and 94.14 mg m−2month−1. Wet nitrogen deposition, including oxidized nitrogen (N–NO3) and reduced nitrogen (N–NH4), showed a non-significant increase. Mean monthly precipitation of N–NO3 and N–N H4 ranged from 1.91 to 451.73 mg m−2month−1. Neither did total sulphur deposition nor total nitrogen deposition exceed the mean deposition values for forests in Europe (below 6 ha−1yr−1 and 3–15 ha−1yr−1, respectively). Our results indicate that air pollutants originate from local sources (households), especially from the village of Białowieża, as demonstrated by the level and spatial distribution of air pollutant deposition. This indicates that air pollutants from the village of Białowieża could spread to other parts of Białowieża Forest in the future and may have a negative impact on forest health and can initiate forest dieback. It is therefore important to continue monitoring air pollution to assess the threats to this valuable forest ecosystem.

The Quality of Winter Wheat Grain by Different Sowing Strategies and Nitrogen Fertilizer Rates: A Case Study in Northeastern Poland

The present study was undertaken to determine the effect of different sowing strategies and spring nitrogen (N) fertilizer rates on the technological quality of winter wheat (Triticum aestivum L.) grain in terms of its milling quality, protein complex quality, and enzyme activity (falling number). Winter wheat grain for laboratory analyses was produced in a small-area field experiment conducted between 2018 and 2021 in the AES in Bałcyny (53°35′46.4″ N, 19°51′19.5″ E, NE Poland). The experimental variables were (i) sowing date (early: 6 September 2018, 5 September 2019, and 3 September 2020; delayed by 14 days: 17–20 September; and delayed by 28 days: 1–4 October), (ii) sowing density (200, 300, and 400 live grains m−2), and (iii) split application of N fertilizer in spring (40 + 100, 70 + 70, and 100 + 40 kg ha−1) at BBCH stages 22–25 and 30–31, respectively. A sowing delay of 14 and 28 days increased the bulk density (by 1 and 1.5 percent points (%p), respectively), vitreousness (by 3 and 6%p, respectively), and total protein content of grain (by 1% an 2%, respectively). A sowing delay of 14 days increased grain hardness (by 5%), the flour extraction rate (by 1.4%p), and the falling number (by 3%) while also decreasing grain uniformity (by 1.9%p). In turn, a sowing delay of 28 days increased the wet gluten content of grain (+0.5–0.6%p) and improved the quality of the protein complex in the Zeleny sedimentation test (+1.5%). An increase in sowing density from 200 to 300 live grains m−2 led to a decrease in grain uniformity (by 2.6%p), the total protein content (by 1.5%), and the wet gluten content of grain (by 0.7%p). A further increase in sowing density decreased grain vitreousness (by 1.4%p). The grain of winter wheat fertilized with 40 and 100 kg N ha−1 in BBCH stages 22–25 and 30–31, respectively, was characterized by the highest hardness (64.7), vitreousness (93%), flour extraction rate (73.9%), total protein content (134 g kg−1 DM), wet gluten content (36%), and Zeleny sedimentation index (69 mL).

Energy allocation is revealed while behavioural performance persists after fire disturbance.

Metabolic physiology and animal behaviour are often considered to be linked, positively or negatively, according to either the performance or allocation models. Performance seems to predominate over allocation in natural systems, but the constraining environmental context may reveal allocation limitations to energetically expensive behaviours. Habitat disturbance, such as the large-scale fire that burnt wetlands of Biebrza National Park (NE Poland), degrades natural ecosystems. It arguably reduces food and shelter availability, modifies predator-prey interactions, and poses a direct threat for animal survival, such as that of the wetland specialist root vole Microtus oeconomus. We hypothesized that fire disturbance induces physiology-behaviour co-expression, as a consequence of changed environmental context. We repeatedly measured maintenance and exercise metabolism, and behavioural responses to the open field, in a root voles from post-fire and unburnt locations. Highly repeatable maintenance metabolism and distance moved during behavioural tests correlated positively, but relatively labile exercise metabolism did not covary with behaviour. At the same time, voles from a post-fire habitat had higher maintenance metabolism and moved shorter distances than voles from unburnt areas. We conclude there is a prevalence of the performance mechanism, but simultaneous manifestation of context-dependent allocation constraints of the physiology-behaviour covariation after disturbance. The last occurs at the within-individual level, indicating the significance of behavioural plasticity in the context of environmental disturbance.

Notes on <i>Candelariella reflexa</i> s. str. (Ascomycota, Candelariaceae) in Poland

This paper presents new localities of the epiphytic lichen <i>Candelariella reflexa</i> (Nyl.) Lettau found in NE Poland. The species has been reported in Poland for over two decades, but the progress of research on the taxonomy of this genus requires confirmation of the data by the currently accepted taxonomic approach. The paper also discusses the diagnostic features of the species that help distinguish it from other similar taxa.

Unobvious geoheritage in sacral buildings: millstones in churches of NE Poland from a geological and geomorphological perspective

The article highlights the importance of medieval churches with embedded millstones as geocultural objects with a great geotouristic and educational potential. In the lowland areas of Northeastern Poland, 79 millstones and their semi-finished products were inventoried. Their sizes ranged from 70 to 100 cm in diameter. The majority of them were made of erratic boulders, mainly granitoids of Fennoscandian origin. Additionally, gneisses, sandstones, pegmatites, and basaltoid were also identified. An attempt was made to determine the degree of weathering of the millstones over several hundred years of exposure to external conditions. Measurements of moisture content and salinity of the walls surrounding 10 millstones embedded in the walls of 8 churches were taken three times (in spring, summer, and winter). Lower wall moisture was observed in the vicinity of the millstones, but only in the case of three walls, the salinity of the mortar binding the bricks and stones was at a low level. A weak but statistically significant negative correlation was found between the age of the churches and the hardness of the millstones measured with a Schmidt hammer.

Hydrology as a Determinant of Riparian Habitat Structure in Lowland River Floodplains

The objective of the study was to determine the relationship between the structure of phytocenoses in riparian wetland ecosystems and the hydrologic regime in a lowland river floodplain. The hydrobotanical study was conducted over three years—2017, 2018, and 2019—which differed in hydrological conditions (wet, average, and dry) in a middle section of the Supraśl floodplain (NE Poland) as a case study. The results showed that the structure and pattern of phytocenoses in the floodplain are primarily controlled by the hydrological regime of the river and the geomorphological features of the area. The reach and duration of the flood contributed to a specific pattern of riparian vegetation. Based on the plant community structure and riparian habitat indicators such as soil moisture, fertility, reaction pH, soil granulometry, and organic matter content, four habitat types were identified and supported by linear discriminant analysis (LDA): wet, semi-wet, semi-dry, and dry zones. The indicator species analysis (ISA) revealed species characteristic of the zones with the dominance of reed rush, reed canary grass, anthropogenic or partially natural herbaceous communities along watercourses or riparian meadows, respectively. Natural inundation of the river water is an important driver of site-specific vegetation elements and habitat types and determines habitat availability, biodiversity, and ecosystem functions of wetlands. This knowledge can serve as the basis for conservation efforts, sustainable management practices, and decision-making processes aimed at maintaining the biodiversity and ecological integrity of riparian ecosystems in similar regions.

Vegetation response to cold climate oscillations during the Holocene – preliminary results of the pollen analysis of the sediments of Lake Boczne (the Great Masurian Lakes District, NE Poland)

Vegetation response to cold climate oscillations during the Holocene – preliminary results of the pollen analysis of the sediments of Lake Boczne (the Great Masurian Lakes District, NE Poland)

Recycling and deposition of inorganic carbon from calcium carbonate encrustations of charophytes

AbstractMany aquatic primary producers can use bicarbonates as a carbon source for photosynthesis. Charophytes of the two genera: Chara and Nitellopsis are quite efficient in this process. Some species of these macroalgae produce carbonate encrustations, mainly calcium carbonate, constituting up to 86% of the summer maximum dry weight of the standing crop. In this study, we analyzed the fate of inorganic carbon accumulated this way in Chara spp. and Nitellopsis obtusa from six Polish lakes located in two regions (warmer W Poland and cooler NE Poland). Our study distinguished two groups of charophyte species that differed in the way of CaCO3 release from their summer standing crops. On average, the corticate Chara rudis and C. tomentosa belonging to the first group were less efficient in depositing CaCO3 from summer to autumn than the less corticate C. contraria and ecorticate N. obtusa of the second group. The latter two species were more efficient in inorganic carbon burial in sediments. On the contrary, dissolution of encrustation was more typical of the first species group and was facilitated by decreasing the pH and saturation index of calcite in lake water. The final output of CaCO3 loss mainly resulted from combined species‐specific features, lake water properties and overwintering patterns. Our study revealed that inorganic carbon cycling through charophytes involves burial and dissolution and is more complex than previously thought.

New fungal non-pollen palynomorphs from moss polsters collected from the Białowieża Forest (NE Poland)

This paper reports on new, previously undescribed non-pollen palynomorphs (NPPs) of fungal origin preserved in moss polsters in a forest environment of a temperate zone. Modern NPPs were recovered from moss samples from 114 sites located in different types of forest ecosystems of Białowieża Forest, north-eastern Poland – a forest complex with a high degree of naturalness, similar to forests that covered large areas of Europe in the past.98 types of fungal NPPs were identified, of which 20 morphotypes presented here are considered new, not previously described. Half of the new remains could be identified to species or genus level, thereby conferring ecological indicator value to them. Each new, determined NPP can be a useful tool in environmental reconstructions.This study shows that moss polsters in forested areas contain many undescribed NPPs, the description and analysis of which can deliver additional ecological information about ecosystems.

Efficiency of emergency conservation methods: a case study of the alcon blue butterfly (Phengaris alcon) and its specific parasitoid

A complicated life history and specific habitat requirements make the Alcon blue butterfly Phengaris alcon a very sensitive species to land-use change. Eggs are oviposited on some Gentiana and Gentianella plants, in whose flowerheads larvae initially feed, after which they continue their development as social parasites in the nests of specific Myrmica ants, once they have been adopted by workers. One of the main threats to their existence is mowing at a time when most individuals are still on gentians. In our research, we tested an emergency conservation method on a site of the butterfly subjected to this kind of pressure in the Białowieża Forest (NE Poland). Previous studies showed that the focal population (dependent on Gentiana pneumonanthe and Myrmica scabrinodis) was characterized by an extremely high density of adults as well as of Ichneumon eumerus, i.e. the rare and specific parasitoid of P. alcon. In mid-August 2020 we performed an unplanned experiment to save caterpillars present in freshly cut plants. We selected about 1800 shoots bearing the eggs or egg shells of the butterfly. Seven hundred and fifty preadoption larvae were transported to the site and placed close to the nests of host ants located in patches without G. pneumonanthe. In the following season we observed that the P. alcon infestation rate of experimental colonies was similar to a control patch, and proportions of parasited pupae did not differ, either.Implications for conservation. Our experiment proved that such actions can be highly effective as emergency conservation methods, and possibly also in (re)introductions of P. alcon.

Assessing the threats of small lowland reservoirs under climate change on the example of Supraśl Water System (NE Poland)

The Supraśl River is a stable water ecosystem in North-Eastern Poland. This is indicated by the flow rate over many years, as well as the water quality monitored for years. Despite this, there are periods of oxygen deficiency in the water, causing massive fish kills. Our research shows that climate change resulting in an increase in the frequency of hydro-meteorological extremes may contribute to negative processes taking place in aquatic ecosystems. On the example of Supraśl Water System (SWS), we present an analysis of the phenomenon of suspension caused by the underground inflow, supplying the surface waters with a significant load of organic matter. The accelerated decomposition of peat formations in the Supraśl River catchment after heavy rains makes it easier for organic matter to penetrate into the aquatic ecosystem. Intensive flushing of valley and river bed sediments during summer floods has a particularly negative impact on the ecosystem of inland waters. If there are organic sediments on the bottom, their re-suspension is very dangerous. Then there is the immediate demand for oxygen, which can lead to deoxygenation of the water. Although this is a natural process, alarm and monitoring procedures should be established and countermeasures sought to respond in time and prevent mass fish kills.

Late-Weichselian (Vistulian) environmental changes in NE Poland – Evidence from Lake Suchar Wielki

By applying pollen and subfossil Cladocera analyses to the Late-Weichselian section of the sediment profile from Lake Suchar Wielki, we aimed to track paleoenvironmental changes in NE Poland, locally (lake formation and its early development) and regionally (terrestrial plant succession). The article aims to indicate how not only stadial-interstadial changes were noticeable in the study area, but above all even short-term climatic fluctuations.The obtained record covers the period of ca. 13,400–11,500 cal. BP, i.e. the part of the Allerød interstadial (GI-1c1 to GI-1a), the Younger Dryas stadial (GS-1), and the very beginning of the Holocene. During the Allerød, a short-lasting cooling was recognized (the Gerzensee oscillation, GI-1b). It is the first study for this part of Poland evidencing the inter-Allerød cooling by the Cladocera-based mean July temperature reconstruction. In the palynological record it was reflected in an increased temporary share of Betula alba t. pollen, while in the Cladocera record in the appearance of cold-water taxa and low total abundance. At the transition to the Younger Dryas further cooling took place that was evidenced by the increase in the proportion of herbaceous plants together with a distinct decrease of tree pollen concentration in sediments as well as by important changes in Cladocera communities including reduced species diversity, disappearance of more demanding temperate taxa and the expansion of cold-tolerant species. The palaeobotanical record revealed that the proportion of juniper pollen in the studied area was lower than in other regions of NE Poland. A case study demonstrated this was mainly due to local conditions. Moreover, it is noteworthy that, at the end of the Younger Dryas, spruce appeared temporarily in local forest stands. The results of the study suggest climate change, which has also been recorded in ice cores from Greenland as cooling ca. 11,800–11,600 cal. BP.

Changes in Stormwater Quality and Heavy Metals Content along the Rainfall–Runoff Process in an Urban Catchment

Stormwater quality in an urban watershed can be influenced by several factors, including land use patterns, atmospheric deposition, and human activities. The objective of this study was to investigate spatial and temporal changes in stormwater quality and heavy metal content during the rainfall–runoff in an urban sub-catchment (30 ha) in the town of Olsztyn (NE Poland). Samples were collected from six locations along the rainfall–runoff pathway, including the following direct rainfall and runoff locations: roof runoff, surface runoff, storm collector, and the river. Parameters such as pH, specific conductivity, fluorescent dissolved organic matter (fDOM), total dissolved solids (TDS), and turbidity were measured in situ, while samples were analyzed for heavy metal content (Cu, Cr, Fe, Ni, Zn, and Pb) in the lab (ICP-OES). The results showed significant changes in water quality along the runoff. The highest concentrations of heavy metals were found in samples from a stormwater collector and surface runoff, particularly in winter and spring, due to the increased deposition of air pollutants and salt washout from roads. This study highlights the importance of monitoring stormwater quality and heavy metals in urban watersheds in terms of impacts on the river ecosystem as a recipient of stormwater. Solutions such as green infrastructure and stormwater management are proposed to mitigate the impacts of urbanization on water quality and protect the aquatic environment.

Palaeoecological and palaeoenvironmental responses to abrupt climate changes during the Late Glacial: The unique archive recorded at the Osinki site (NE Poland) and its regional importance

The reconstruction of environmental changes at the termination of the Last Glaciation range in NE Europe during the Late Glacial is hampered by the multiplicity of processes underway at that time and during the Holocene that dynamically modified the Young Glacial landscape. In lake sediments, these changes are recorded in a manner that is almost always incomplete or disturbed. For this reason, the succession that was successfully reconstructed in two profiles from the Osinki site in NE Poland is extremely valuable. Palynological, Cladocera and geochemical analyses, as well as fragmentary malacofauna and diatom analyses, made it possible to trace the changes in the environment that took place in two differently functioning parts of a single lake, in not interrupted periods from the Oldest Dryas to the Younger Dryas. Detailed research results show that despite the proximity of natural environment components, their developments in both cases were conducted in different ways, what they prove to the changes in pollen record, Cladocera, and geochemical composition of sediments. Climate changes affected the changes in the vegetation, the composition of malacofauna, Cladocera and diatoms. They also influenced the erosion processes within the catchment and the oxidation-reduction conditions. On the basis of the research results, changes in water trophy, from oligotrophic to eutrophic, were also observed. In this case, we also observe significant differences between the two analysed profiles. These changes first occurred in Allerød in the shallow part of the lake, and then in its deeper zone in Young Dryas.In addition, Late Weichselian profiles from the Poland–Belarus–Lithuania borderland area were analysed in detail, and the age of the bottom of sediments is usually estimated to the Allerød, and the Bølling. The results of analyses from Osinki and Osinki2 profiles (beginning of sedimentation in the Oldest Dryas) indicate that the reason for this discrepancy is to be found in, among other things, the methodological limitations of the palynological analysis for most of the sites. The above-standard amount of mineral sediment allows the age of the sediment to be established as being much older than if determined using only pollen analysis of organic sediments.