Quaternary

We present a record of pollen and spores of coprophilous fungi from a sediment core from Auel infilled maar, Eifel, Germany, covering the period from 42,000 to 36,000 yr b2k. We can show that vegetation cover was dominated by a boreal forest with components of steppe and cold-temperate wood taxa. The proportion of wood taxa was higher during interstadials, whereas steppe-vegetation became more prominent during stadials. During Heinrich stadial 4, temperate taxa are mostly absent. Spores of coprophilous fungi show that megaherbivores were continuously present, albeit in a larger number during stadials when steppe environment with abundant steppe herbs expanded. With the onset of Greenland stadial 9, forests became more open, allowing for steppe-environment to evolve. The shift in vegetation cover coincides with the highest values of herbivore biomass at the time that Neanderthal humans demised and Anatomically Modern Humans most probably arrived in Central and Western Europe. Megaherbivore biomass was a direct consequence of vegetation cover/availability of food resources and thus an indirect consequence of a changing climate. Herds of large herbivores following suitable (steppe) habitats may have been one cause of the migration of AMH into Europe, going along with their prey to productive hunting grounds. Full article

Nowadays, wild grapevine populations are quite limited and sporadic mainly due to habitat destruction, land-use change, and the spread of pathogens that have reduced their distribution range. Palaeoecological, archaeobotanical, and genetic studies indicate that modern cultivars of Vitis vinifera are the results of the domestication of the dioecious, and sometimes hermaphrodite, wild species standing in riparian zones and wet environments. Wild grapevine populations have declined as a consequence of various forms of anthropogenic disturbance and were assigned by the IUCN Red List of Threatened Species to the Least Concern category. The River Crati Natural Reserve (Riserva Naturale Foce del Crati), located in southern Italy, hosts a population of Vitis vinifera subsp. sylvestris in a rewilding wet forest close to the Ionian Sea. These protected areas are of high scientific, biogeographic, and conservation interest in terms of Mediterranean biodiversity. Dendroecological and pollen morpho-biometric analyses of the wild grapevine are presented in this study. Palaeoecological perspectives for a landscape management strategy aimed at conserving and restoring the relic grapevine population are discussed. Full article

This essay is a personal insight based on my own experience in the Iberian Pyrenees, which addresses three situations common in paleoecological research, such as the verification of previously devised hypotheses (anticipation), the finding on unknown events in unstudied sites (discovery) and the finding of unexpected outputs in already known areas (serendipity). The account is concentrated on the value of the coring sites by themselves as generators of paleoecological knowledge, rather than on the actual findings, which are presented and discussed in the corresponding data papers. The main aim is to show that there is still much room for new findings, even in areas that have been surveyed for a long time and are supposed to be well known, from a paleoecological perspective. Finally, some general lessons are derived and conceptualized. Full article

Well-preserved Quaternary sedimentary sequences in the central coast of Ecuador have provided sufficient relevant information for paleogeographic reconstruction and climatic evolution, from stratigraphic, geochemical, and biological analysis. The Jaramijo canton site is one of the most remarkable results in the stratigraphic correlation of lithological units with delineation of a paleo sea-cliff of age ¹⁴C 43,245 ± 460 B.P. (belonging to the MIS-3). This MIS-3 is associated with a period of glaciation, but the data obtained, such as δ 18O, indicate paleo-temperature values of −1 to −1.5, which are interpreted in this study, indicate that the central coast of Ecuador has an interstadial phase (warm years in a glacial stage). Two more paleo-coastal cliffs have been mapped from orthophoto analysis, but these are younger. The sedimentary levels analyzed in this study include deposits that occurred in MIS 3 to MIS 1. Holocene transgression has modified the central coast of Ecuador and increased the level of coastal climate hazard by sea level rise. Indeed, paleo-coastlines have been evidenced from bathymetric data in the depth contours of −5.5 m and −7.6 m, at 440 and 650 m distances from the up-to-date coastline. For the Jaramijó site, the rate of cliff-erosion and wave-cut platforms are in the order of 1.1 to 2.4 m/yr. These cliff-erosion rates, with a moderate to high coastal vulnerability index, can be increased if we consider mathematical models with an estimated sea-level rise scenario to be, in 2100, about +1 to +1.4 m. Full article

Mining activity at Taxco produces seven mining waste deposits, which are problematic for the health of the community and for the environment in general. This study targets the Guerrero I mining waste dam (the youngest of the region), located south of Taxco de Alarcon, in the northern portion of Guerrero State, Mexico. This study reports the vertical magnetic susceptibility prospecting results and geochemical characterization of 27 tailing samples from the Guerrero I dam. Results from magnetic techniques provide evidence for different deposit layers of variable mineral composition, in agreement with the lithological column. The short evolution period of this relatively young dam is corroborated by the practically constant and close to 1 S_-300 ratio (low oxidation degree of the magnetic mineralogy) and the mainly neutral pH character at the dam’s upper part. Most maximum concentrations of potentially toxic elements are below the maximum permissible levels for agriculture/residential use, except for those of Pb and Zn, with average enrichment factors above 90 and 50 times the corresponding regional background concentrations, respectively. Simple sample preparation and fast magnetic and X-ray fluorescence elemental concentration measurements, together with a suitable systematic sampling distribution, result in an advantageous proxy method for a quick and cost-effective heavy metal evaluation of mining waste dams. Full article

Lake Kolon (Hungary), situated in the middle of the Turjánvidék area between the saline lakes of the Danube valley and the Homokhátság, is one of the most significant natural aquatic habitats in the Danube–Tisza Interfluve region. The central question of this study is how the lake changed, and how environmental factors and human activities have influenced these paleoenvironmental changes in Lake Kolon. A multiproxy analysis of a core sequence (loss on ignition, grain size, magnetic susceptibility, and geochemistry) provided crucial insights. Notably, correlations are observed in the following relationships: (1) clay, organic matter, and elements derived from organic sources, such as Na, K, and Zn; (2) MS, sand, inorganic matter, and elements originating from inorganic sources, such as Fe, Al, Ti, Na, K, and P; and (3) carbonate content and elements originating from carbonate sources, such as Ca and Mg. The lake’s paleoenvironment underwent significant changes in the past 27,000 years. Late-Pleistocene wind-blown sand provided the bottom for an oligotrophic lake (17,700 BP), followed by a calcareous mesotrophic Chara-lake phase (13,800 BP). Peat accumulation, along with the eutrophic lake phase, began at the Pleistocene–Holocene boundary around 11,700 BP. From 10,300 BP, with the emergence of an extended peatland phase, the percentage of organic matter (peat) increased significantly. Anthropogenic changes occurred from around 9000–8000 BP due to the different emerging cultures in the Carpathian basin, and from 942–579 BP due to the Hungarian settlements and activity nearby, respectively. Full article

This study covers the examination of four loess–paleosol profiles in Hungary through grain size composition, organic matter, carbonate content and magnetic susceptibility measurements. One of the profiles (with a thickness of 25.72 m) can be found in the Gödöllő hills, on the border of town Pécel, and the other three profiles (Kisdorog-West—5.60 m, Kisdorog-East—6.40 and Bonyhádvarasd—8.16 m) are located in the Tolna hills of the Transdanubia region. The sections were continuously sampled with an interval of 4 cm. The same interval was also applied to the other three profiles. During the field exploration of the Pécel profile, we were able to study the complete loess wall, which was deposited on the sediment of the nearby Rákos stream. Based on the Ostracod fauna of the clay sediment beneath, the fluvial deposit can be considered as originating from the Upper Miocene. In the case of the Transdanubian sections, a significant change can be observed in the prevailing wind direction based on the grain size analyses. In addition, the results of magnetic susceptibility measurements suggest that the development of the Pécel profile took place during MIS 9–10, while the age of the three Transdanubian sections can be assumed to be the MIS 2–4. Full article

Understanding sedimentation processes in response to past hydrogeological and climatic changes and capturing millennial-scale variations is a key focus of lacustrine paleoenvironmental research. This study presents the first high-resolution chronology and sedimentary data for the small thermal-spring-fed Lake Pețea, NW Romania, and unravels the evolutionary history of the lake harboring a unique endemic fauna. Its small size and single source of water make it particularly sensitive to hydrological changes. In the recent past, over-exploitation of the thermal water has led to the complete drying up of the lake and the extinction of its fauna. Nevertheless, past spatio-temporal variation of environmental factors, in particular the fluctuation of lake levels and water temperature, must have had a significant impact on the survival and evolution of the endemic mollusk fauna. This fact makes this study particularly important. Based on our results, a three-stage sedimentary evolution occurred, mainly controlled by major climate-driven hydrological changes also seen in regional records, i.e., 17.5–14.5 ka shallow eutrophic lake, 14.5–5.5 ka oligotrophic carbonate-rich lake, and 5.5–0.5 ka shallow eutrophic lake. A major lowstand at 11.7–10.2 ka due to drier climate was followed by progressively rising water levels up to 5 ka followed by a drop. The main control on lake level fluctuations and sedimentary phases was the varying input of thermal water due to recurring increased/decreased recharge of the underground shallow karst water system. The driving factor of thermal water discharge was different during the Late Glacial than the Holocene. It was the warming of the climate at 14.5 ka cal BP and melting of regional ice sheets in addition to increased precipitation that created an oligotrophic lake by recharging the underground thermal water system. Conversely, during the Holocene, increasing/decreasing moisture availability driven by major climate forcings was in control of thermal water recharge, erosion, and fluctuating lake levels. Full article

This research focuses on the recent pollen image of several vegetation types in NW Italy. In 201 arboreal, shrubby, and herbaceous plant populations, pollen samples were taken from moss polsters, and the corresponding vegetation was recorded using the phytosociological method. Since studies on recent pollen rain in the Mediterranean mountains and coast are rare, this research aims to provide new data and tools to better interpret fossil pollen spectra. Pollen analysis provided data for the comparison between surface spectra and vegetation. Davis indices, fidelity, dispersion, and the relation with vegetation data were calculated for each taxon, and PCA was carried out. Most vegetation types are identifiable through the taxa dominating the pollen spectra, as frequently happens in woodlands (e.g., beech woods, chestnut woods, etc.). Characterizing shrubland and certain tree-dominated vegetation types (e.g., Larix forests) through pollen data is more complex. In this regard, Davis indices are particularly useful for identifying pollen/plant association, over- and underrepresentation of pollen, and taxa indicating vegetation types. Pollen threshold values were calculated which allow the assessment of the local presence of a plant. Overall, the achieved results partially confirm those of previous research carried out in the region, greatly expanding the comparisons between several different plant communities and the database in view of future sharing through the EMPD. Full article

Fluvial terrace formation is a complex process governed by the interplay of climatic and tectonic forcings. From a climatic perspective, an incision is usually related to climatic transitions, while valley aggradation is attributed to glacial periods. We have reconstructed the formation of Late Pleistocene fluvial terraces along the middle, mountainous section of a temperate zone river (Mureş/Maros) in order to identify the roles of different climatic periods and potential vertical displacement in terrace development. Investigations were based on two profiles representing two different terrace levels. The profiles were subjected to sedimentological and detailed geochronological analyses using optically stimulated luminescence (OSL). The results indicated that the investigated terraces represent different incision events coinciding with climatic transition periods. However, a joint MIS 3 valley aggradation period can be identified at both of them. Thus, the relatively mild but highly variable climate of the MIS 3 facilitated sediment mobilization from upland catchments. On the other hand, there is no evidence of aggradation under the cold and stable climate of MIS 2. However, the tectonic setting favours incision at the site. Based on our results, we concluded that the timing of the main events was controlled primarily by climatic forcing. The terrace formation model recognised might also be applied at other rivers in the region. Full article

This paper presents palynological data obtained from a trench excavated at the Neolithic pile-dwelling archaeological site of Palù di Livenza (northeastern Italy). The site is in a wetland located in a tectonic basin at the foot of the Cansiglio plateau, crossed by the Livenza river. Environmental conditions have made this wetland a suitable area for settlements since prehistoric times. Thanks to the peaty sediments that characterise the area, archaeological materials and botanical remains have been exceptionally well preserved. Their study has shed light on a Neolithic pile-dwelling settlement that developed in various phases between c. 6350 and 5600 cal BP (c. 4400 and 3650 BC), and has also allowed for a detailed environmental reconstruction of the surrounding environment. A vertical sequence of 20 samples was analysed to study pollen, non-pollen palynomorphs and microcharcoals. An age-depth model was performed based on three radiocarbon dates. The palynological analysis provided insight into the response of vegetation to environmental changes caused by both climatic fluctuations and human pressure. In this sense, it was possible to highlight differences in vegetation cover, some fires, the use of woody resources, the spread of cereal fields, as well as the presence of other cultivated plants and plant processing by the people within the village. Full article

Phytolith analysis is a well-established archaeobotanical tool, having provided important insights into pre-Columbian crop cultivation and domestication across Amazonia through the Holocene. Yet, its use as a palaeoecological tool is in its infancy in Amazonia and its effectiveness for reconstructing pre-Columbian land-use beyond archaeological sites (i.e., ‘off-site’) has so far received little critical attention. This paper examines both new and previously published soil phytolith data from SW Amazonia to assess the robustness of this proxy for reconstructing pre-Columbian land-use. We conducted the study via off-site soil pits radiating 7.5 km beyond a geoglyph in Acre state, Brazil, and 50 km beyond a ring-ditch in northern Bolivia, spanning the expected gradients in historical land-use intensity. We found that the spatio-temporal patterns in palm phytolith data across our soil-pit transects support the hypothesis that pre-Columbian peoples enriched their forests with palms over several millennia, although phytoliths are limited in their ability to capture small-scale crop cultivation and deforestation. Despite these drawbacks, we conclude that off-site soil phytolith analysis can provide novel insights into pre-Columbian land use, provided it is effectively integrated with other land-use (e.g., charcoal) and archaeological data. Full article

The Late Holocene fossil pollen records from the Zemu glacier, located in Yabuk, North Sikkim, in the eastern Himalayas, effectively generated quantitative climate reconstructions based on the transfer function model. The transfer function model was developed by establishing a modern pollen–climate calibration set from the temperate alpine belt of North Sikkim. A redundancy analysis was carried out to detect the pattern of variation of climatic variables in the modern pollen datasets. The mean annual precipitation (MAP) and mean temperature of the warming month (MTWA) had the strongest influence on the composition of the modern pollen samples among the climatic variables considered in the analysis. Proxy data in the form of fossil pollen records were analyzed for reconstructing past climate based upon the relationships between modern pollen vegetation assemblages and climatic patterns. Transfer functions for MAP and MTWA were developed with the partial least squares (PLS) approach, and model performance was assessed using leave-one-out cross-validation. The validated model was used to reconstruct MAP and MTWA for the last 2992 cal years BP (1042 BC) in North Sikkim. The variability observed in the reconstructions was analyzed for past global climatic events. It was further compared with the available regional and hemispheric proxy-based climate reconstructions. The reconstructions captured comparable Medieval Warm Period (MWP) and Little Ice Age (LIA)-like events from the Zemu glacier region. The fossil pollen data and climate reconstructions were further compared with the mineral magnetism data of the subsurface sediment profile. Full article

While the North American mylodont sloth, Parmylodon harlani, has been identified in multiple localities in Mexico, most of these records are from the southern part of the country. Consequently, there is a large geographic gap between its distribution in Mexico and the more northern records of the species in the United States. The recovery of the remains of multiple individuals of Paramylodon harlani, as part of a late Pleistocene fauna in San Clemente de Térapa, Sonora, Mexico, partially fills this geographic gap and provides a broader understanding of the differences in the species’ ecology over a wide latitudinal range. A comparison of the paleoecology of the Térapa site with other sites with P. harlani in the fauna to the south and north provides valuable information on how regional topography and different plant communities impact the sloth’s distribution and underlying causes for its extinction. Full article

The Gulf of Corinth is a semi-isolated basin in central Greece interrupting the Pindus Mountain Range, which nowadays is a biodiversity hotspot. Considering its key location, deep drilling was carried out within the International Ocean Discovery Program (IODP; Expedition 381: Corinth Active Rift Development) aiming to improve our understanding of climatic and environmental evolution in the region. Here, we present a new long pollen record from a Mediterranean setting in the southernmost tip of the Balkan Peninsula recording the vegetation succession within the Quaternary. The Corinth pollen record shows no major shifts in arboreal pollen between glacial and interglacial intervals, while Mediterranean and mesophilous taxa remain abundant throughout the study interval. During interglacials, the most frequent reconstructed biomes are cool mixed evergreen needleleaf (CMIX) and deciduous broadleaf forests (DBWB), while graminoid with forb (GRAM) and xerophytic shrubs (XSHB) dominate within glacials. Our findings support the hypothesis that the study area was a significant refugium, providing suitable habitats for Mediterranean, mesophilous and montane trees during successive Quaternary climate cycles. Full article

Buried river valleys from the Neogene–Quaternary time are widespread throughout the Middle Volga region of the Russian Plain. They have been studied for a long period, since the 1940s, with the last major generalizations dating back to the 1980s. This paper presents new results based on GIS mapping using materials from the state geological study of the region in 1960–1970, 1984–1996 and 2000–2002. On the whole, the pattern of the buried valley network is close to the modern valley network of the region. During the Quaternary, the right-sided displacement of the valley incisions prevailed. The incisions of modern river valleys are located above the Neogene (pre-Akchagyl) incisions almost throughout the entire territory. The vertical displacement amplitude ranges from 30 to 200 m. The morphometric characteristics of the paleovalleys (the depth and width of the incisions, as well as the gradients of the bottoms of the paleovalleys) exceeded modern ones. The maximum values were typical for the middle Paleo-Volga valley: the width of the valley reached 10 km, the incision depth was−201.4 m below sea level and the bottom gradient was 0.9–5.0 m/km. The most important factor that influenced the position of paleovalleys and their morphological appearance was fluctuations in the level of the Caspian paleowaterbody. According to this study, the development of paleovalleys began in the Miocene and ended in the Early Quaternary. The alluvial–lacustrine type of sedimentation was predominant. The results of this work contribute to the study of the paleogeography of the Cenozoic of the southeast of the Russian Plain. Full article

Crop yield prediction is one of the crucial components of agriculture that plays an important role in the decision-making process for sustainable agriculture. Remote sensing provides the most efficient and cost-effective solution for the measurement of important agricultural parameters such as soil moisture level, but retrieval of the soil moisture contents from coarse resolution datasets, especially microwave datasets, remains a challenging task. In the present work, a machine learning-based framework is proposed to generate the enhanced resolution soil moisture products, i.e., classified maps and change maps, using an optical-based moderate resolution imaging spectroradiometer (MODIS) and microwave-based scatterometer satellite (SCATSAT-1) datasets. In the proposed framework, nearest-neighbor-based image fusion (NNIF), artificial neural networks (ANN), and post-classification-based change detection (PCCD) have been integrated to generate thematic and change maps. To confirm the effectiveness of the proposed framework, random forest post-classification-based change detection (RFPCD) has also been implemented, and it is concluded that the proposed framework achieved better results (88.67–91.80%) as compared to the RFPCD (86.80–87.80%) in the computation of change maps with σ°-HH. This study is important in terms of crop yield prediction analysis via the delivery of enhanced-resolution soil moisture products under all weather conditions. Full article

Earthquake precursors are the indicators that appear before an earthquake. The release of radon gas, ionospheric disturbances, anomalous animal behavior, and so on are examples of seismic and aseismic events. Ionospheric perturbations can be proved to be a reliable method in earthquake prediction. The GNSS data detect changes in the ionosphere through the time lag of the transmitted GPS signals recorded at the Earth-based receivers. A negative TEC anomaly is caused by the stress released from the rocks before the earthquake, which elevates positive ions or p-holes in the atmosphere and decreases the ions in the ionosphere. A positive TEC anomaly follows this because of the increase in ions in the ionosphere. The ionospheric disruption in the Himalayan region is examined before five random earthquakes. For this, data from 15 separate GNSS stations are investigated using IONOLAB-TEC. A promising total electron content (TEC) data estimate with a temporal resolution of 30 s was analyzed. The results of the TEC data analysis depict the anomaly a month before the five earthquakes, followed by the later perturbation in the earthquake preparation zone. TEC anomalies are enhanced more by the uniform spatial distribution of GNSS stations in the epicentral region than by randomly distributed stations. The results of IONOLAB-TEC and the widely used GPS-TEC software were compared. Owing to its temporal resolution, IONOLAB-TEC has edge over the GPS-TEC software in that it can identify even the slightest negative anomalies before an earthquake. Full article