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The vicinity of the Rozprza archaeological site (central Poland) has been the area of a series of palaeoecological studies tracking the environmental history of the Luciąża River valley up to ca. 13,200 cal. BP. Numerous subfossil palaeomeanders of different sizes have been discovered in the valley floor. Here, we present the first results of multiproxy research on the paleo-oxbow lake fill, one of the oldest in the region. The wide range of palaeoecological analyses resulted in reconstructions of vegetation history, climatic, hydrological and habitat changes. The studied oxbow was an aquatic ecosystem with diverse invertebrate fauna until the end of Younger Dryas when it transformed into a limno-telmatic habitat. The sediment composition indicates active denudation processes and several episodes of turbulent hydrological conditions. Such an increased river activity could have caused flooding, resulting in an allochthonous matter supply to the oxbow lake in Late Vistulian. Environmental changes were strictly related to the regional features of the catchment, the transformation of soils, and the hydrogeological conditions. The chironomid- and pollen-inferred climatic reconstructions indicate periods of high and low continentality. The chironomid record indicates relatively cool summer conditions in the Allerød, especially ca. 13,000 cal. BP, possibly related to the Gerzensee Oscillation. On the other hand, a distinct increase of summer temperatures in Younger Dryas (up to 16 °C) was recorded. Such a situation was also confirmed in some other studies from the region, suggesting that it might be the effect of some specific, local palaeoclimatic conditions. Fundator badań: Fundator badań: Optional.empty

The paper presents new data on the subfossil insects and molluscs, as well a new radiocarbon date for the Gornovo site in the Southern Fore-Urals. As a result, the stratigraphic interpretation of the sediments of the lower part of the first above floodplain terrace of the Belaya River is corrected and they are assigned to the Tabulda Horizon (MIS 3) of the Upper Pleistocene in the regional scheme of the Fore-Urals Quaternary. The malacofauna of the locality is represented by 27 species of terrestrial and freshwater molluscs. The composition of molluscs in the deposits of MIS 3 indicates the succession of deposit accumulation in the river valley from the stage of reservoirs that periodically connecting with the river to the stage of the overgrown oxbow lake. Single occurrence of mollusc shells in the loams of MIS 2 is a result of sharp climate change. New insect material includes 136 species of Coleoptera from 17 families, as well as Heteroptera and Hymenoptera representatives. 29 species of beetles (Carabidae, Histeridae, Scarabaeidae, Elateridae, Tenebrionidae, Chrysomelidae, Brentidae and Curculionidae) are recorded for the Pleistocene for the first time. The insect assemblages from Gornovo site are assigned to periglacial and humid boreal faunal types. The entomofauna of the periglacial type has no analogues in the recent fauna; it corresponds to the deposits assigned to the middle of MIS 3. This entomofauna is characteristic to the MIS 2 and MIS 3 insect assemblages from the south of West Siberian Plain. Based on entomological data, the climate of the middle of MIS 3 of the Southern Fore-Urals is reconstructed as dry and cold, extracontinental, with mean July temperature not exceeding +15 °C. Steppe landscapes likely prevailed in open areas and coniferous forests were restricted to river valleys. Beetles from deposits dated to end of MIS 3 are assigned to the fauna of the boreal humid type. These insect assemblages are significantly poorer in diversity than periglacial type assemblages and are represented mainly by near water and forest Coleoptera. Based on these species, meadow and forest landscapes were reconstructed. The reconstructed mean air temperature of July ranged from +16 to +19 °C. This suggests a trend towards more mild conditions in the region connected to the climate warming at the end of MIS 3. It is likely that humidification during this period was regional, determined by the proximity of the site to the Southern Urals Mountains.

Lake ecosystems in arid Central Asia are in crisis due to water abstraction and eutrophication, and it is important to understand their response to combined climate and human impacts. In this study, based on the relationship between modern chironomids and salinity, we studied subfossil chironomid remains in a ~4550-year sedimentary record from Lake Ulungur in northwest China, with the aim of reconstructing past ecosystem dynamics, especially in response to climate change and human impacts. The results show that from 4550–580 cal yr BP the hydrological status of Lake Ulungur was transformed from close to open and the salinity decreased causing an increase in freshwater chironomid species. Comparison with regional paleoclimatic records makes us to infer that the lake ecosystem evolution has been primarily controlled by changes in the westerly driven by the Northern Hemisphere insolation. Since 580 cal yr BP, the lake returned to be closed and the structure of the aquatic community reorganized. In recent centuries, human activities have made a more significant effect on lake ecosystems in northwest China than natural climate changes, which largely was induced by a surge in the human population related to national policies. Furthermore, due to the combined effects of global warming and intensifying human activities, lake ecosystems in Central Asia are subject to unprecedented anthropogenic pressures and urgent action is needed to protect them.

Subfossil remains of the Quaternary megafauna from two Ukrainian natural history collections stored at Kaniv Nature Reserve and the National Museum of Natural History NAS of Ukraine were examined. Most of the bones were collected in 1965–1966, in the building pit and the gateway of the Kaniv hydroelectric power plant. The fauna is represented at least by ten taxa (Gulo gulo, Mammuthus trogonterii chosaricus, Mammuthus intermedius, Coelodonta antiquitatis, Megaloceros giganteus, Alces alces, Bison priscus, Cervus elaphus, Capra cf. ibex, and Equus ferus). Skeletal parts are represented mainly by skulls, long bones, horns, and tusks. Based on the species composition of proboscideans, at least part of the faunal assemblage is dated by the end of the Middle Pleistocene (Dnieper Stage = Saale, Warta, MIS 6), but majority of bones could be older or younger (Late Pleistocene and Holocene age) due to the alluvial origin of accumulation.

Cladocerans are biological indicators of environmental changes. Their remains provide information on past changes in lake environments. We studied the correspondence between contemporary Cladocera assemblages and their subfossil remains from an oxbow lake. We sought to demonstrate that there were differences among the various sites of an oxbow lake with different utilization based on contemporary and subfossil Cladocera assemblages and physical–chemical variables. The oxbow lake’s two sides are used as fishing sites, where angling is the main activity. The middle site of the lake is under nature protection with high macrovegetation coverage. Contemporary and subfossil Cladocera assemblages were sampled from 21 sampling sites along the oxbow lake. Our research showed that the subfossil Cladocera assemblages had higher species richness and densities (36 taxa) than the contemporary species (29 taxa). We found one species of the Polyphemidae family only in the contemporary assemblage. Among the sites, Cladocera assemblages differed in their species composition and density. The highest densities were found in the second fishing site due to the appearance of the small-sized Bosmids. The relationship between Cladocerans and the physical–chemical variables showed that some variables, such as chlorophyll-a, biological oxygen demand, dissolved oxygen, copper, phosphide, and organic matter content, significantly affected Cladocera composition. We found that the subfossil Cladocera assemblage was significantly more diverse and abundant than the contemporary one, indicating that an integrated sampling may be sufficient to provide better results on the total species composition of the water body.

The physical, mechanical, and chemical properties of both stem wood and knot wood were investigated from two subfossil Scots pine (Pinus sylvestris L.) trunks retrieved from a lake in Finnish Lapland, dated to 404–486 CE and to 1318–1444 CE. Both the stem wood and the knot wood of the younger trunk had higher moisture content, lower density, and lower strength properties in comparison to the older trunk. The ash content of the stem wood of the younger trunk was lower, but the ash content of the knot wood was higher than that of the older trunk. Due to the degradation that occurred over time, all the values of physical and mechanical properties were lower compared to typical values of recently grown Scots pine wood. The chemical composition of both stem wood samples was close to the composition of the recently grown wood, and the only exception was the small decrease of the cellulose and hemicellulose in the subfossil samples. The bulk extractives were well-preserved, but terpenes and fatty acids underwent transformation, resulting in more stable compounds. The SWOT analysis (strengths, weaknesses, opportunities, and threats) showed pros and cons for the productization of subfossil wood, with the branding value of an ancient material being the potential enabler in developing commercial niche uses.

In the Netherlands, several proxies of climate change during the Last Glacial-Interglacial Transition (LGIT) (c. 14,700 to 11,700 b2k) have been investigated in detail over the last few decades. The present paper presents two tree-ring chronologies LETR-A (n = 16, timespan 106 rings) and LETR-B (n = 24, timespan 201 rings) from in situ subfossil pine remains (Pinus sylvestris) discovered at Leusden-Den Treek in the Netherlands that date from the Bølling-Allerød interstadial (GI-1). Using a multiproxy approach (both abiotic and biotic), it was possible to study local woodland development in detail as part of long-term environmental change. Moreover, the trees opened up possibilities for dendrochronological and dendroclimatological research. The tree-ring series show the occurrence of two successive phases of pine woodland development, which were 14C dated with high precision and calibrated using the recent IntCal20 14C calibration curve: 13,450–13,396 to 13,370–13,316 calBP (series LETR-A) and 12,952–12,937 to 12,754–12,739 calBP (series LETR-B). At the north-western boundary of its ecotone, Pinus was highly sensitive to climate change during the latter part of GI-1 and the transition to GS-1. The inability to set fruit and the disappearance of the pine woodland within decades before and after c. 12,745 calBP is interpreted as the vegetational response to abrupt climate deterioration at the start of the Younger Dryas (12,807 ± 12 cal BP).

At present, most lakes in the world are facing the threat of eutrophication, especially mesotrophic lakes, which are in a critical period of ecosystem transformation. However, how the internal biological composition and structure of these lakes change accordingly has not yet been explored extensively. Here, a paleolimnological evaluation of subfossil Cladocera was initiated to study ecological and hydrological environmental changes in Nanyi Lake, which is a large (203 km2) shallow freshwater lake in the lower reaches of the Yangtze River Basin, China. In this study, subfossil Cladocera data combined with several geochemical proxies from three well-dated sediment cores were obtained. Both the sedimentary subfossil Cladocera and the modern Cladocera in the water column indicated that Bosminidae was the dominant species in Nanyi Lake. We observed that the changes in the density of Bosminidae and Cladocera had strong ties to changes in the cultivated land area, which could cause the obvious alteration of the sedimentation rate around the lake. In addition, the ratio of planktonic species to littoral species (P/L ratio) in Nanyi Lake responded to the occurrence of several extreme hydrological phenomena, such as flooding corresponding to a high P/L ratio and drought corresponding to a low P/L ratio, during the past 200 years. The analysis of Cladocera assemblages and the geochemical indices of the three cores in Nanyi Lake indicated increases in trophy and water levels, especially since the modern 1970s.

Combined use of radiocarbon-dated subfossil wood within lateral moraines and surface exposure ages on moraine boulders provides an approach to better constrain times of glacier advance and onset of retreat. We test this method at Gilbert Glacier in the southern Coast Mountains of British Columbia where units of sediments associated with glacier expansion date to 4.8–4.6, 4.5–4.3, 4.0–3.9, 3.8–3.6, 3.4, 3.2–2.9, 2.7, and 0.5–0.3 kilo calendar years BP (ka; 2-sigma age range). Surface exposure (10Be) ages reveal times of moraine stabilization at 1.83–1.78, 1.38–1.28, 0.85–0.76, and 0.13–0.06 ka (interquartile range). Analysis of both datasets, as well as previously published regional advance records, narrows the age range of four late Holocene advances to 2.0–1.8, ∼1.5–1.3, ∼0.9–0.8, and 0.4–0.1 ka. We advocate for widespread use of our tandem approach at other sites throughout Earth's high mountains to narrow the uncertainties associated with glacier expansion and better understand how glaciers respond to climate change.

Fennoscandia is one of the most prominent regions in the world for dendroclimatological research. Yet, millennium-long tree-ring chronologies in this region have mainly been developed from Scots pine (Pinus sylvestris L.). To explore the possibility of building long-term chronologies using other dominating tree species in the region, this paper presents the first two millennia-long Norway spruce (Picea abies (L.) Karst.) ring-width chronology from Northern Europe. The chronology is composed of living trees and subfossil wood and covers the period from BCE 115 to 2012 CE. A sufficiently replicated and robust chronology is built for the past 360 years back to 1649 CE. Further back in time, the common growth signal is reduced, and hence the reliability of the earlier section of the chronology is lower. The climate calibration results show that the spruce ring-width correlation with June-July mean temperatures over the period 1901–2012 is positive and significant (r = 0.6, p

Subfossil Pediastrum, a genus of green algae (Chlorophyceae) which is sensitive to changes in the aquatic environment, is a potential proxy indicator of the evolution of aquatic ecosystems and climate change. We synthesized subfossil Pediastrum records from arid central Asia (ACA) and the Asian summer monsoon (ASM) region in order to characterize their hydro-climatic evolution during the Holocene. In ACA, low concentrations of subfossil Pediastrum during the early Holocene resulted from the higher salinity caused by a dry climate or lower lake levels. The increasing trend of subfossil Pediastrum content during the middle-late Holocene is consistent with the occurrence of wetter regional climatic conditions. In the marginal areas of the Asian summer monsoon (MASM) region of northern China, the variations in subfossil Pediastrum concentration coincide with increased summer monsoon rainfall during the middle Holocene, but concentrations were generally lower during the late Holocene as a result of increased salinity or alkalinity associated with a weakened summer monsoon. In the Tibetan Plateau, the variations in subfossil Pediastrum abundance are more complicated due to divergent moisture/precipitation patterns influenced by both the ASM and the mid-latitude westerlies. In the Indian summer monsoon-dominated region, subfossil Pediastrum abundance was high during the early Holocene and then gradually decreased after ~8 cal kyr BP. The observed asynchronous changes in subfossil Pediastrum in ACA and the MASM region during the Holocene may reflect the specific moisture/precipitation patterns of the monsoon- or westerlies-dominated climatic regimes. We suggest that high evaporation in arid and semi-arid areas would have rapidly increased the salinity and/or alkalinity of lakes, while aquatic environments may have been more stable in more humid areas.