Renata Stachowicz-Rybka

The Late Glacial and Holocene development of vegetation in the area of a fossil lake in the Skaliska Basin (north-eastern Poland) inferred from pollen analysis and radiocarbon dating

ABSTRACT The development of vegetation in the Skaliska Basin has been reconstructed on the basis of palynological analysis and radiocarbon dating (AMS technique) of 6 sites from the late phase of the Bolling- Allerod interstadial complex to modern times. Although the area covers 90 km2, the mosaic character of habitats led to the development of different patterns of vegetation changes during the Late Glacial and Holocene. Only one site located in the eastern part of the Skaliska Basin reflected the ‘pine phase’ of Allerod, and this is the oldest data on vegetation in the Skaliska Basin. Interesting discrepancies were recorded during the Younger Dryas when patches of shrublands with Juniperus were distinct around some of the sites, while steppe with Artemisia was common in others. The beginning of the Holocene brought an expansion of birch-pine forest, but around 9600 cal. BC a cold oscillation took place which was reflected in an increase in birch in the woodlands in the western and eastern part of the Skaliska Basin. In the Preboreal chronozone elm (Ulmus) also expanded in the area but its appearance was non-synchronous. The vegetation of the Boreal chronozone was similar in the whole area and the most characteristic feature was the rapid expansion of hazel (Corylus avellana) which displaced Betula from the most of its sites. At that time a distinct redeposition of pollen material in the Parchatka river valley was detected which was probably the effect of an increase in fluvial activity of the river (humid oscillation). The following stage of vegetation development was climax woodlands with Tilia cordata, Ulmus, Quercus, Corylus avellana, and Alnus in damp places. At the beginning of the Subboreal chronozone the expansion of Quercus took place, which was subsequently replaced by Picea abies and partly Carpinus betulus. The pattern of Picea abies expansion distinctly presents two maxima which is characteristic of many sites in the north-eastern Poland. The Subatlantic chronozone is represented only by the profile from the Skaliski Forest, where, because of sandy ground, Pinus sylvestris was the dominant element. Human impact was poorly reflected through the rare occurrence of pollen grains of Cerealia type in the pollen profiles spanning the time from the Subboreal chronozone to modern times. In most profiles AMS dating produced age discrepancies, which limited the possibility of establishment of a detailed chronology. However, dates obtained from the material contaminated by mixture of glycerine, thymol and ethyl alcohol, pretreated by alcohol, showed reliable results in most cases.

The development and genesis of a small thaw lake filling the Skaliska Basin during the Late Glacial and Holocene

ABSTRACT The northern part of the Mazury Lake District is marked by the presence of a depression described as the Skaliska Basin. At the end of the Pleistocene, the Skaliska Basin was the site of functioning of a thaw lake, within series of laminated clayey sediments were formed. The surface of the clayey sediments was overlain by a sandy fan. Blocks of dead ice underlying the fan and the overlying surface of the clayey sediments were the origin of small isolated water basins. Since the Allerod they were filled with limnic sediments, passing into peats towards the upper part. In order to reconstruct the vegetational history of the Skaliska Basin and the conditions of sedimentation of the lacustrine gyttjas and peats, several sections were obtained from such basins and subjected to examination of plant macroremains, palaeolimnological analysis and AMS dating. Sedimentation of lacustrine sediments began with sands with an admixture of silt and peat. The beginning of sedimentation of lacustrine sands of aeolian origin falls within the Allerod, whereas the end of that process in ca the middle of the Preboreal. Sands are frequently overlain by a strongly decomposed lacustrine dy sediment. Subsequently a sequence of detritus gyttja accumulated. The complex of gyttjas is interbedded with occasional Scirpo-Typheti peats. Sedimentation of lacustrine sediments is followed by accumulation of peats formed within communities with tall sedges. These communities, according to their compoition, correspond to the associations of Cicuto- Caricetum pseudocyperi Boer. et Siss. and Caricetum elatae Koch. The upper part comprises peats resembling the present-day community of Sphagnum centrale, displaying features of a transition bog. Also the occurrence of Eriophorum vaginatum confirms changes towards ombrotrophic conditions. The uppermost part of the sections often comprises heavily decomposed peat with components no longer identifiable by macroscopic analysis.

Record of environmental and climatic changes in middle Pleistocene sediments from Łuków (eastern Poland) on the basis of plant macroremains analysis

Abstract Lacustrine sediments at the Łuków site bear a record of the Ferdynandovian interglacial, correlated with Marine Isotope Stage (MIS) 13-15, including two warm periods of interglacial rank (climatostratigraphic units Ferdynandovian 1 and 2) separated by cooling/glaciation (Ferdynandovian 1/2). On the basis of plant macroremains analysis, the type of local vegetation in the lake and its surroundings as well as changes in climate, trophic conditions and water level were reconstructed in detail. Ferdynandovian 1 was a time of development of tall sedge swamps. The presence of Najas marina and N. minor also suggests high levels of eutrophication, particularly in the younger part of the climatic optimum. The occurrence of Zannichellia palustris indicates habitats of variable water level and high salt content. In the terminocratic phase of Ferdynandovian 1, the communities showed the reoccurrence of Betula nana, B. humilis and Larix sp., the disappearance of thermophilous trees, and the intensification of succession processes linked to climate cooling. In the cool Ferdynandovian 1/2, Betula nana and Cenococcum geophilum increased their frequencies, most likely due to enhanced supply of mineral matter to the basin. During Ferdynandovian 2, the next climate warming of interglacial rank, communities of aquatic vegetation with the highest share of thermophilous taxa included the extinct Aldrowanda borysthenica, Brasenia borysthenica, and Scirpus atroviroides, as well as Cyperus glomeratus, a species not presently found in the flora of Poland. Another cooling in the Sanian 2 (Elsterian 2) glaciation is indicated by the development of peat communities, with numerous Carex sp., Menyanthes trifoliata, Eriophorum vaginatum, and Andromeda polifolia, accompanied by the extinct Carex paucifloroides, Caulinia macrosperma, and Potamogeton praemaackianus. The provided description of the Ferdynandovian succession includes taxa which are extinct, not found in the Polish flora nowadays, or characteristic of a climatic context. The identified species included Brasenia borysthenica, Aldrovanda borysthenica, Caulinia macrosperma, Potamogeton praemaackianus, Scirpus atroviroides, Cyperus glomeratus, Eleocharis praemaximoviczii, Nymphaea cinerea, and Ranunculus gailensis. It has not yet been resolved whether the flora of Łuków includes Euryale sp., a particularly important taxon.

Palaeobotanical studies on Late Glacial and Holocene vegetation development and transformations of the ‘Wielkie Błoto’ mire near Gołdap (north-eastern Poland)

ABSTRACT This paper presents the results of palynological, macrofossil and peat analyses that were conducted on deposits from a profile collected from the Wielkie Błoto mire near Bałupiany (north eastern Poland). The investigation revealed that the recorded changes of vegetation span the period from the decline of the Younger Dryas (ca 9600 cal. yr BC) to the late Subboreal or early Subatlantic chronozone, but due to a 40 cm long sediment gap a complete reconstruction was not possible. At the beginning, the area was occupied by steppe and tundra communities together with abundant Juniperus stands. A subsequent expansion of birch (Betula) woodlands with pine (Pinus sylvestris) took place in the Preboreal chronozone in which a rise in the water level and/or basin deepening was recorded at the site as well. The domination of such woodlands lasted to the end of the Boreal chronozone when Corylus avellana expanded rapidly. In the Atlantic chronozone multispecies deciduous forests developed with Tilia cordata and Quercus, while Ulmus together with Alnus spread in damp habitats. During this chronozone, traces of the occurrence of Carpinus betulus were detected in the macrofossil analysis, while the pollen analysis failed to record its presence. The expansion of Carpinus betulus and Picea abies was characteristic of the Subboreal chronozone when both taxa presented antagonistic optima. Alone in north-eastern Poland, there was a re-expansion of deciduous forest in the younger part of the Subboreal chronozone caused probably by low human impact, which is reflected in the whole profile. The first probable traces of human activity were noticed in the Atlantic chronozone and attributed to peoples of the Mesolithic or Early Neolithic cultures, while the first evidence of cultivation was correlated to the Bronze Age. However, the low resolution of the radiocarbon dates did not allow a more precise reconstruction of the chronology. The analysis of macrofossils and tissues indicated two episodes of oligotrophication of the mire. The first one took place during the Boreal chronozone, while the second fall in trophy was triggered by spruce expansion in the Subboreal chronozone. On the other hand, a rise in human impact during the first Carpinus betulus maximum caused eutrophication of the mire.

Vegetation of the Ferdynandovian interglacial (MIS 13–15) based on plant macrofossils from a new profile of the stratotype site

Abstract Early Middle Pleistocene palaeolacustrine sediments of the Ferdynandów site (E Poland), serving as a stratotype for the Ferdynandovian interglacial, were subjected to a new drilling in 2011. The obtained profile, covering the late Sanian 1 glaciation, two interglacial successions (Ferdynandovian 1 and 2), the cold Ferdynandovian 1/2 interval, and the early Sanian 2 glaciation, permitted a high-resolution plant macroremains analysis, correlated with the results of a palynological examination. In detailed studies of plant macroremains from the profile, new taxa were discovered for the Polish Pleistocene flora: specifically, species that are extinct or not found nowadays in Poland. On the basis of the taxonomic diversity and occurrence of bioindicators, the division into warm and cold units of the Ferdynandovian interglacial as well as units associated with the Sanian 1 and 2 glaciations, already applied in pollen studies, were confirmed, and the periods were described in terms of plant macroremains. The Ferdynandovian succession is correlated with the Cromerian Complex (Cromerian III and IV) in the Early Middle Pleistocene of Western Europe, as well as with Marine Isotope Stages (MIS) 13-15. New geological and palaeobotanical data enabled a description of the palaeogeographic context and conditions of functioning, as well as the evolution of the interglacial lake at the stratotype site. The outcome of plant macroremains analysis is presented and interpreted in comparison with corresponding results previously obtained for the Ferdynandów B profile, studied by Janczyk-Kopikowa (1975). Particular consideration is given to similarities between the succession of Ferdynandów 2011 and the profiles of Ferdynandów B and the nearby drilled Łuków 3A. Study of the macrofossil flora of Ferdynandów 2011 revealed the presence of species absent in the archival Ferdynandów B. Taxa not formerly recorded in early Middle Pleistocene floras, such as Brasenia borysthenica, Aldrovanda borysthenica, Pilularia borysthenica, Caulinia goretskyi, and Potamogeton saryanensis, were identified. These species and other taxa of stratigraphic or climatic significance provided the basis for a more detailed description of the Ferdynandovian flora, afterwards compared with other stratigraphically corresponding Polish and European early Middle Pleistocene floras. The composition of characteristic taxa also was used for comparisons between two bimodal interglacial sequences, namely the Ferdynandovian (correlated with MIS 13-15) and Augustovian (correlated with MIS 19-21), and the Domuratovian succession (correlated with MIS 17).

Environmental and climate changes reflected in the Domuraty 2 section (NE Poland) based on analysis of plant macroremains

Abstract Research in the Domuraty 2 section was focused on a series of lacustrine-river-swamp deposits in which the full spectrum of vegetation and climate changes was recognised in a detailed analysis of plant macroremains and a comparison with the results of pollen analysis. Based on plant macrofossil data, two (Dom II, Dom III) of three palynologically documented warm units were distinguished in the Domuraty succession. The palaeobotanical data from the Domuraty succession document several successive local vegetation changes in both interglacial and glacial periods, which can be related to global climate oscillations. The succession of local vegetation stands and changes in the vegetation, climate, water level, and trophy during the period of the Domuraty succession were analysed and compared with corresponding parameters of the Augustovian and Ferdynandovian interglacials. The taxonomically most diverse unit is Warm unit Dom II, with the highest share of taxa with high thermal requirements, which was compared to the older Augustovian (A II) and younger Ferdynandovian (F II) units. The comparison of the Domuratovian interglacial flora to that of the Korchevian interglacial in Belarus shows high similarity; most of the extinct taxa or taxa unknown in the present-day flora are common to the Korchevian and Domuratovian floras, suggesting similar age for these two communities. However, the Domuratovian flora lacks a few species important to the Korchevian flora, such as Stratiotes goretskyi, Carex rostrata-pliocenica, Brasenia sp., Caulinia antiqua, Aldrovanda borysthenica, and A. zusii.