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Chu et al. (2015, Lilliput effect in freshwater ostracods during the Permian–Triassic extinction) reported a sharp decrease of the size of freshwater ostracods through the terrestrial end-Permian extinction (EPE) interval of the Dalongkou Anticline section in Northwest China. The proposed work is however unacceptable because of taxonomic and methodological issues. Most of the identifications are rejected because of too poor preservation and generic misidentifications due to the unawareness of the abundant literature published for years on Permian freshwater ostracods. The proposed analysis of the size of the misidentified genus Darwinula considers the totality of the recovered specimens but is meaningless by ignoring the aspect of the ontogenetic development of ostracods. As a consequence, the observed reduction of size of ostracods could be related to changes in the taphonomic conditions or in the proportions of juveniles under special environmental, which have already been suggested for marine ostracods through the EPE. [ABSTRACT FROM AUTHOR]

The Indo-Pacific Warm Pool (IPWP) is the primary supplier of heat and moisture to the global atmosphere, and exerts a significant impact on tropical and worldwide climate variability. This special issue expands our understanding of the paleoceanographic and paleoclimatic evolution of the IPWP since Neogene times with implications for understanding future change. It contains fifteen research articles addressing two primary themes: (1) Ocean-atmosphere coupled processes via the ocean water-column, sea surface, atmospheric evaporation/precipitation; and (2) Sediment source-to-sink and biogeochemical carbon-cycles, and their interactions with oceanographic, hydrological, tectonic and other factors. These contributions improve our understanding of thermocline temperature, salinity, oxygenation, hydrography, carbon cycle, biological productivity, and sedimentary response in the IPWP across Neogene and Quaternary time scales, as well as aiding in the forecast of future climate responses in the context of current global warming. The special issue will capture the attention of geologists, climatologists, and anybody else interested in global climate change. • This is the editorial preface for the VSI on Indo-Pacific Warm Pool. • 15 papers are included and shortly introduced. • Two themes are included. • The 15 papers provide new views on paleoceanographic and paleoclimatic changes in the Indo-Pacific Warm Pool. [ABSTRACT FROM AUTHOR]

The silicon (Si) cycle is intimately interlinked with other biogeochemical cycles (e.g., carbon and nitrogen) and plays an important role in regulating long-term global climate change and biotic evolution in Earth's history. The abundance of cherts in Mesoproterozoic shallow-marine carbonates implies unique environmental conditions for silica precipitation, but the driving mechanism behind the Si cycle in Mesoproterozoic oceans remains unclear. In this paper, we report an integrated study of the cherts from the ∼1.48 Ga Wumishan Formation of North China. The Wumishan cherts predominantly consist of microquartz (∼90%), with some silica-replaced carbonate (∼5%) and minor pyrite (∼1%) grains, indicating that the cherts were largely formed through primary silica precipitation. High germanium/silicon molar ratios (Ge/Si = 0.71–19.1 μmol/mol; mean = 8.83) and positive europium anomalies (Eu/Eu* = 0.41–2.42; mean = 1.41) of the cherts suggest a considerable contribution from hydrothermally derived Si. Diverse microbial components, including organic-rich filaments, EPS (extracellular polymeric substances) relics, mat fragments and picocyanobacteria fossils, are observed in the Wumishan cherts. These components, together with abundant organominerals resulted from the interactions of microbes and dSi in ambient environments, imply that microbial activities played critical roles in silica deposition. The Si liberated from degraded EPS or EPS-Si complex may have locally increased the dSi concentrations and changed chemical conditions in the substrate and pore-waters, promoting silica precipitation. Given that picocyanobacteria and some other prokaryotes can accumulate significant amounts of silica in their cells and EPS, biogenic silica from decomposed microbial biomass may have exerted an important influence on silica precipitation in shallow-marine environments of the Mesoproterozoic ocean. [Display omitted] • Chert deposition in the ∼1.48 Ga Wumishan Fm was promoted by decomposed EPS-Si. • Si primarily sourced from seawater with a low contribution of hydrothermal-fluid silica. • The dSi concentrations of ∼0.67–1.0 mM estimated for the chert deposition lower than previous estimates for Precambrian oceans. • Microbial processes played critical roles in silica polymerization and the chert formation. [ABSTRACT FROM AUTHOR]

The Holocene Temperature Conundrum refers to the mismatch between proxy-based temperature records and those based on climate model simulations. A possible reason for this mismatch is a putative proxy-based bias in reconstructed summer temperatures, and therefore, regional reconstructions of seasonal temperature are crucial for resolving the conundrum. In this paper, we reconstruct vegetation and climate changes over the last ∼10,000 years BP based on a high-resolution pollen record from Gushantun peatland, Changbai Mountains, Northeast China. Multiple quantitative reconstruction approaches were used and weighted averaging partial least squares regression (WAPLS) was found to be the most appropriate method for reconstructing Holocene temperature and precipitation. The reconstructed climate record shows that the Holocene Climate Optimum occurred between 8 ka and 6 ka and exhibited a cold month mean temperature that was 3 °C warmer than modern temperatures. Climate gradually cooled during late Holocene with a minimum cold month temperature of −19.6 °C. Four prominent cold events occurred around 8.7 ka BP, 7.8 ka BP, 5.7 ka BP, and 2.5 ka BP with an amplitude variation up to 3 °C. The synthesized seasonal temperature time series and a comparison with other proxies show that the decreasing trend in mean annual temperature is not a seasonal bias caused by summer temperature change. This study provides evidence of a Holocene seasonal temperature change at a regional scale and insights for further understanding of the Holocene Temperature Conundrum. • Reconstructed seasonal temperature changes based on a new high-resolution fossil pollen record in the Changbai Mountains • Synthesized climatic series in Northeast China to investigate the characteristics of regional temperature changes and their driving factors • Reconstructed winter temperature as evidence to address the alleged seasonal bias for the Holocene temperature conundrum [ABSTRACT FROM AUTHOR]

Hainan Island in southern China is situated within the Indo-Burma biodiversity hotspot, and has attracted the attention of evolutionary biologists, geologists, and biogeographers. However, the palaeogeography of Hainan Island and its relationship with mainland China remains contested. In this paper, we report RAD-seq data for Engelhardia roxburghiana populations from Hainan Island and adjacent mainland areas to identify genetic diversity, structure, divergence time, and demographic dynamics over geologic time. Findings were assessed using climate model data to constrain suitable distribution areas. Results indicate that E. roxburghiana dispersed from the Chinese mainland to Hainan Island via a hypothetical land bridge during the late Eocene so that the drift of Hainan Island was impossible. We cast doubt on the hypothesis that Hainan Island was connected to Vietnam and Guangxi at this time. We emphasize that higher genetic diversity in the Yunnan-Guizhou Plateau and Chiang-nan regions is the result of mixed populations or the existence of refugia, and lower genetic diversity in the Indochina Peninsula is due to a historical bottleneck. From the late Eocene to Oligocene, the arid belt that dominated East Asia retreated, facilitating the expansion of E. roxburghiana from the Indochina Peninsula to southern China. The main diversification of E. roxburghiana occurred in the Miocene following the strengthening precipitation within the East Asian Summer Monsoon. Climatic oscillations during the Quaternary led to the contraction of E. roxburghiana in the Indochina Peninsula, with expansion after Last Glacial Period (LGP; 119 to 11.7 ka). Southern China has served as a refugium and continues to do so in the future. In summary, our study elucidates the evolutionary trajectory of E. roxburghiana through large-scale sampling, providing insights into the palaeogeography of Hainan Island and itsbiogeographic relationships with adjacent mainlands. • A land bridge facilitated the spread of Engelhardia roxburghiana from Chiang-nan to Hainan Island in the late Eocene. • Engelhardia roxburghiana 's evolution follows Asian climate shifts, spreading north as arid zones retreated. • The diversification of Engelhardia roxburghiana occurred concurrently with intensified EASM precipitation during the Miocene. • Southern China was the refugium during the Quaternary glaciations and continues to do so in the future. [ABSTRACT FROM AUTHOR]

Dynamic fluctuations in sea surface temperature within the North Atlantic Ocean (NA-SST) exert a pivotal influence on global climate change. Yet, the specific impacts of these variations on the temperature shifts within the Qinling-Bashan Mountains (QBM) of China, remain to be fully elucidated. Furthermore, a debate surrounding the manifestation of the Little Ice Age (LIA) within the QBM is ongoing, primarily due to the scarcity of reliable, long-term, and high-resolution temperature records. To bridge these knowledge gaps, in this paper, we present a ∼ 250-year temperature reconstruction (Tmax 11 – 7) developed based on a tree-ring-width chronology from the QBM. The new reconstruction not only aligns with a local winter temperature reconstruction based on historical document evidence, but also reveals robust regional and hemispheric temperature signals. Intriguingly, the study shows that the warming trend observed in the QBM since the Industrial Era is less pronounced than that witnessed across China and the Northern Hemisphere. The Tmax 11 – 7 reconstruction provides a glimpse into the final stages of the LIA, highlighting a relatively colder 19 th century followed by a warmer 20 th century. Notably, the warming trend post-1970s remains within the bounds of the 250-year temperature framework. The research further uncovers that NA-SST has predominantly governed the QBM's temperature fluctuations over the past centuries, as evidenced by the tight positive correlation between Atlantic multidecadal Oscillation (AMO)/Atlantic multidecadal variability (AMV) and Tmax 11 – 7. However, this dominant influence of NA-SST was temporarily subdued between 1900 and 1930 CE due to the interference of Pacific Decadal Oscillation (PDO). This finding serves as a reminder that future temperature projections for the QBM must account not only for the primary role of NA-SST but also the modulating effects of the PDO. The study is essential for shaping effective environmental management and adaptation strategies in the region. • A ∼ 250-year temperature reconstruction is developed using tree rings from the QBM. • The QBM saw the last stage of the LIA and recent warming is within historical frame. • North Atlantic SST (NA-SST) played a positive and dominant role on QBM'S temperature changes. • Weakened NA-SST's impact on temperature in 1900–1930 CE was due to PDO's interference. [ABSTRACT FROM AUTHOR]

The Arctic Ocean is rapidly warming. In this paper, we document changes in the source, distribution, and accumulation rate of organic matter (OM) for three sediment cores in the Bering and Chukchi seas to investigate changes to the oceanic carbon cycle over the past ∼75 years. Analyses were undertaken using bulk properties, such as total organic carbon (OC), total nitrogen (TN), stable carbon isotope (δ13C), OC to TN molar ratio (C/N), and biomarkers (lignin phenols). The OC, TN, and lignin (Σ8, in mg (g sediment)−1) contents were found to be significantly related to the fraction of sand (Sand%) as a result of sediment sorting and/or different sediment sources. Using an end-member mixing model, we estimated marine OM accounted for ∼67% of all organic matter in all cores, being the dominant source. Moreover, terrestrial OM mainly originated from angiosperm non-woody tissue, while moss contribution was negligible. In the Bering Sea shelf, OC% has not changed over time, but there have been some extreme peaks around the 1960s–1970s and in 2005, which correspond to increased terrestrial input from North American rivers. In the southern core from the Chukchi Sea, the OC% showed an apparent decrease after 2000, accompanied by an increase in sand content, likely due to enhanced delivery of volcanic rocks by the Pacific Inflow from the Bering Sea. In contrast, in the northern core from the Chukchi Sea, the OC% showed a significant increasing trend, with some peaks occurring at the same time as in the Bering Sea core. The mean increase rate was compared to the increase in Siberian riverine discharge, which both could be caused by long-term climate changes. The results highlight the regional differences in the response of OC preservation to climate change and other controlling factors. Further studies with higher spatial resolution are required to better understand the preservation of OC in response to climate change. [Display omitted] • The main vegetation source was vascular plant, contribution from moss was limited. • Marine source accounted for ∼67% of the sedimentary OC in the (sub)Arctic cores. • OC preservation changed differently in the (sub)Arctic Ocean in past decades. [ABSTRACT FROM AUTHOR]

The periodicities of the climate change have long been explored by researchers not only because they reflect the inherent characteristics of the climate systems, but also because they are the foundations of climate-change predictability. This paper reports the periodicities of the hydroclimate variations reconstructed from a lacustrine sequence at Tiancun section (TC section) in the Luoyang Basin within the Central Plains of China and the sequence covers the first half of the Holocene. Our reconstruction shows that the hydroclimate variations at the TC section during the period from ∼10,135 and ∼ 5890 cal. yr BP were well corresponding with the effective soil moisture variations recorded by the stalagmite δ13C sequence at the Magou Cave. This corresponding relationship suggests that when the effective soil moisture increases (i.e., more negative δ13C values), the ratio of evaporation over precipitation in the paleolake at the TC section decreased, resulting in lower CaCO 3 content. It also suggests that when the effective soil moisture increases, more inflowing water entered the paleolake, resulting in coarser sediments. Our reconstruction also shows that the hydroclimate variations or lake level variations in the Luoyang Basin were characterized by millennial-scale quasi-periodicities that were most likely paced by the changes in ITCZ (Inter-tropical Convergent Zone) position and also by alterations in ENSO-like phase. And, both (ITCZ and ENSO) were most likely regulated by the solar activity. Our further analysis shows that the hydroclimate in the Luoyang Basin also experienced centennial-scale variations. Specifically, the grain size data express the following cycles: 692-year, 538-year, 217-year, 170-year and 123-year, all at the 99% confidence level. And, the CaCO 3 content data express the following cycles: 202-year, 184-year, 169-year and 85-year, all at the 99% confidence level. These cycles are approximately coincident with the widely-reported solar-activity cycles. • This paper reports the periodicities of the hydroclimate variations reconstructed from a lacustrine sequence in the Central Plains of China and the sequence covers the first half of the Holocene. • The hydroclimate variations were primarily paced by changes in ITCZ position and also by alterations in ENSO-like phase. And, both (ITCZ and ENSO) were most likely regulated by solar activity. • The centennial-scale hydroclimate variations were approximately coincident with the widely-reported solar-activity cycles. [ABSTRACT FROM AUTHOR]

Focusing on the evolution of coral reefs in the South China Sea, this special issue is dedicated to enhancing our understanding of Holocene environmental and climate changes in the region and their driving mechanisms. It comprises twenty-four papers organised into seven themes: (1) Palaeoclimate and palaeoenvironment evolution recorded by coral reefs; (2) Palaeo-ENSO activity recorded by coral reefs; (3) Palaeo-storm activity recorded by coral reefs; (4) The formation and evolution of coral reefs; (5) Carbonate diagenesis in coral reefs; (6) The application of new geochemical record indicators to coral reefs; and (7) Lipid biomarker records in coral reefs. This special issue provides an improved understanding of Holocene paleoclimates and paleoenvironments within the South China Sea, and the development of its coral reefs. It is hoped that these findings will deepen our knowledge of the natural and anthropogenic processes that contribute to climate and environmental change in the region, and aid the long-term protection of coral reef systems. • This special issue on recent advances of coral reefs in the South China Sea comprises twenty-four papers. • This special issue focuses on the evolution of coral reefs and their records on paleoenvironmental and paleoclimate changes. [ABSTRACT FROM AUTHOR]

The combined effects of climate change and human disturbance has degraded lake ecosystems worldwide in recent times, but there are few studies that explore the relative impact of these factors over long timescales. In this paper, we use sedimentary pigment data to reveal variations in algal abundance and the lake ecological environment of a typical subalpine lake (Beilianchi Lake) in the southwestern Chinese Loess Plateau, to distinguish the relative effects of natural climate change and human disturbance over the past 5000 years. Our data show that between 5000 and 1400 cal yr BP, algal abundance exhibited a slow decline without obvious fluctuations, mainly driven by a gradually drying and cooling climate. After 1400 cal yr BP, algal abundance showed large and rapid fluctuations characterized by a pattern of a decline, then increase, and then decline again. During this period, human activities began to affect lake ecology and gradually overshadowed the role of climatic changes as the main driving factor. Enhanced human disturbances caused a rapid and synchronous decline in algal abundance due to increases in soil erosion and reductions in water transparency. Algal biomass levels recovered when the soil erosion intensity decreased during 800–500 cal yr BP corresponding to the period from Southern Song to Yuan Dynasties. Thereafter (during the period of Ming and Qing Dynasties), as human activities became further enhanced and the soil erosion intensity became very high, the lake ecosystem rapidly transitioned to a stable state of low algal growth. This indicates that the lake ecosystem may have had the capacity to recover from moderate external disturbances in the early stages of human activity, but the resilience of the lake ecosystem began to decrease under stronger human disturbances. Our findings provide important empirical evidence for evaluating the current state of lakes and for sound lake management in the future. • High-resolution sedimentary pigment data reveal the lake ecological evolution of an alpine lake since 5000 yr BP. • Human activities began to exceed climate in driving lake ecological changes since 1400 yr BP. • The effect of human activities on lake ecological changes is more dramatic. • Lake ecosystem may have the capacity to recover from moderate human disturbances. [ABSTRACT FROM AUTHOR]

The sedimentary sequences of the Yangtze River delta comprise important Quaternary records of tectonics, sea-level oscillation, and climatic change; however, analysis is hampered by a lack of a reliable chronological framework. In this paper, we present an integrated chronology for two sedimentary sequences (core ZKW2 and ZKW4) on the southern side of the Yangtze River delta, based on magnetostratigraphy and absolute methods (OSL, 14C, and ESR dating). The basal ages of the core ZKW2 and ZKW4 are ca. 2.25 Ma and 2.96 Ma, respectively. The integrated chronology indicates significant increases in the sedimentary accumulation rate at ∼0.15 Ma, rather than the Matuyama-Brunhes boundary as indicated by magnetostratigraphy alone. The observed sedimentary transition is possibly controlled by regional subsidence of the Zhe-Min Uplift, and climate evolution during the last interglacial period. • High-quality magnetostratigraphy is obtained for the Quaternary sediments in the YRD. • The SARs of the YRD sediments significantly enhanced since ∼0.15 Ma. • Tectonics and climate factors jointly control the sedimentary evolution in the YRD. [ABSTRACT FROM AUTHOR]

This paper is a review article focussing on the research on past environments of Zimbabwe. The paper synthesises the current knowledge on palaeo-climates and other environmental parameters that inform debates and discussions on climate change and human adaptation. The study of palaeoenvironments provides environmental knowledge that chronologically goes beyond the range of written climatic records that are available in the country. The palaeoenvironmental data now available shows that our human ancestors in Zimbabwe have survived numerous climatic upheavals since the beginning of the Stone Age. However, limited research in the Stone Age and the variety of proxy data available creates a less coherent record. Extrapolation of evidence from the region makes the data less reliable for archaeological interpretations. The paper shows conflicting signals across the region at some specific periods. There are numerous gaps in the record. The paper concludes by calling for multidisciplinary research on the past environments of Zimbabwe. [ABSTRACT FROM AUTHOR]

Coastal wetlands provide valuable ecosystem services and understanding their response to past climatic changes may help predict their possible future responses. In this paper, we obtained records of pollen, algae, sediment grain-size, and other environmental proxies, from a late Holocene sediment core (CFD-E) from the Caofeidian area, on the northwest coast of the Bay of Bohai, China. Our results indicate three major stages of environmental change. During Stage I (3500–2800 cal yr BP), arboreal pollen content was high (mostly >60%), especially for Pinus and Quercus , and the PCA sample scores on Axis 1 were negative indicating that regional vegetation was temperate broadleaved forest and the climate was wet. During Stage II (2800–2350 cal yr BP), the arboreal pollen content decreased substantially (mostly <40%), and the PCA Axis 1 sample scores were positive indicating a decrease in forest vegetation, grassland expansion, and a drier climate. During Stage III (2350–1400 cal yr BP), the arboreal pollen content increased again (mostly >40%), although it remained lower than during Stage I, indicating that forests expanded under a relatively humid climate while the wetland area decreased slightly. Our results also record the 2.8 ka and 2.4 ka events of monsoon weakening, which were characterized by increases in herbaceous pollen (indicating grassland expansion) and the drying of the regional climate. There are several differences in the regional expression of these two climatic events. During the 2.4 ka event, Chenopodiaceae pollen increased substantially (average of 42.0%), indicating the expansion of halophytes; whereas during the 2.8 ka event, an increase in Artemisia indicates the occurrence of a dry climate throughout the region. We suggest that the aridity during the 2.8 ka event was triggered by decreased solar activity and the resulting changes in the El Niño-Southern Oscillation, which weakened the East Asian summer monsoon. However, we suggest that the 2.4 ka event was driven by the weakening of the Atlantic Meridional Overturning Circulation. • Significant increase in halophytic vegetation during 3500–1400 cal yr BP • The 2.8 ka and 2.4 ka events were characterized by climate drying lasting ∼150 years. • During these two events the area of forest decreased and grassland expanded. [ABSTRACT FROM AUTHOR]

The Carnian Pluvial Event (CPE) induced an intense carbon-cycle disturbance and biological crisis at a global scale. The eruption of the Wrangellia Large Igneous Province (W-LIP) is considered a possible triggering mechanism; however, this cannot fully explain the significant differences in environmental perturbations across different regions. In this paper, we present detailed records of petrography, mercury geochemistry, carbon and sulfur isotopes, trace elements, and provenance data for the Triassic lacustrine facies of the Ordos Basin in the North China Plate, which provide insights into the important effects of volcanic activities, other than the W-LIP, on palaeoenvironment during the CPE interval. Massive emissions of SO 2 , CO 2 , and pyroclastic deposits resulting from these volcanic activities triggered four humid episodes, each characterized by lake-level rise, negative δ13C org excursion, a transition from mudstones to organic-rich shales facies, as well as algal bloom within a time span of 180 kyrs. The establishment of an age framework in the Ordos Basin enables comparative analyses of environmental evolution during the Carnian age across the North China Plate, the western Tethys domain, and the South China Plate. During the period of global climate perturbation driven by the W-LIP eruption, we conclude that short-term localized volcanic activities may have further induced high frequentcy environmental perturbations, which influenced biological shifts and increase organic carbon burial. These short-term volcanic activities with different occurrence times and frequencies complicate local-scale palaeoenvironmental evolutions, which may be an important reason contributing to significant differences in environmental perturbations during the CPE interval across different regions of the globe. • Four humid episodes and sedimentary changes occurred within 0.18Ma in the Ordos Basin during Carnian age. • Environmental changes in the Ordos Basin was related to the local volcanisms in its nearby Qinling orogenic belts. • Short-term local volcanisms can complicate the environmental evolutions in different parts of globe during the CPE interval. • Local volcanic processes may cause inconsistent environment perturbation in different parts of globe during the CPE interval. [ABSTRACT FROM AUTHOR]

The distribution pattern of arid–humid climate in the modern northwest–southeast confrontation in Asia evolved from the zonal distribution pattern of the Paleogene. However, this evolutionary process remains poorly constrained by geological evidence. In this paper, we analyze the characteristics of sporopollen assemblages recorded in Late Eocene strata of the Jianchuan Basin in southwest China. We show that vegetation patterns exhibited a remarkable shift from tropical–subtropical sparse forest to subtropical–temperate mixed broad-leaved–coniferous forest at ∼40.6 Ma; this shift is further indicated by the rapid decrease in drought-tolerant plants, mostly Ephedra and Chenopodiaceae, evidence that the previous hot–dry climate was replaced by a warm–humid climate at this time. This evidence suggests that the Asian monsoon began to affect the study area at ∼40.6 Ma. We then comprehensively integrated sporopollen results from several basins across East Asia, revealing that the frontal edge of the humid monsoon climate moved intermittently to the northwest after the Late Eocene, and may have advanced to the Lunpola–Lanzhou line by the early Late Oligocene, this being similar to the position of the leading edge of the modern monsoon. Moreover, the frontal edge of the humid monsoon climate may have extended as far as the Qaidam Basin during the Middle Miocene, but then gradually retreated to the position of the modern monsoon front. The uplift of the Tibetan Plateau and global climate change may have played dominant roles in this evolution. • A Late Eocene sporopollen record was obtained from the subtropical Yunnan region. • The Asian monsoon extended from tropical to subtropical regions around 40.6 Ma. • The Asian monsoon reached the modern monsoon front in the early Late Oligocene. • The Asian monsoon advanced on one occasion to the Qaidam Basin in the Mid-Miocene. [ABSTRACT FROM AUTHOR]

Mountain glaciers are one of the most sensitive indicators of climate change. Reconstructing past glacier extents provides valuable insights into the climate change for specific regions where instrumental records are not enough and even absent. In the paper we mapped the outlines for 691 Little Ice Age (LIA) glaciers in terms of prominent moraines beyond contemporary glaciers in the Tanggula Mountains, central Tibetan Plateau (TP). Based on these glacier outlines, we reconstructed the ice thicknesses and surfaces for the LIA glaciers in the region. Accordingly, we calculated the equilibrium-line altitudes (ELAs) for contemporary and LIA glaciers. By comparing the ELAs between the contemporary and LIA glaciers, we estimated the LIA summer temperature decreases in different subregions of the Tanggula Mountains. Since the LIA, the ELA have risen by 35.6 ± 18.8 m, 26.1 ± 17.6 m, and 63.1 ± 38.6 m in the respective western, central, and eastern subregions of the Tanggula Mountains. Assuming no change in precipitation, the LIA summer temperature would decrease by 0.22 ± 0.12 °C, 0.14 ± 0.09 °C, and 0.34 ± 0.21 °C in the three subregions, respectively. Moreover, glaciers in the western, central, and eastern subregions have lost 13.3%, 23.9%, and 42.8% of their area, 15.4%, 25.3%, and 39.6% of their length, and 20.8%, 39.0%, and 61.0% of their volume, respectively. By compiling the LIA ELA data from previous studies, we also estimated the LIA summer temperature changes for other regions of the TP. The LIA ELA and summer temperature changes relative to the present showed a decreasing trend from the edges towards the interior on the TP. • LIA glaciers and summer climate were reconstructed at the Tanggula Mountains. • LIA summers were 0.22 ± 0.12 °C, 0.14 ± 0.09 °C, and 0.34 ± 0.21 °C cooler than present in three subregions. • Summer temperature change had a decreasing trend from the edges towards the interior on the Tibetan Plateau. [ABSTRACT FROM AUTHOR]

Southwestern China, a biodiversity hotspot, underwent dramatic climate change following the Last Glacial Maximum and intensive human activity also exerted a major impact since the late Holocene. In this paper, we report a pollen record from Yilong Lake in Yunnan Province, southwestern China, to understand vegetation response to long-term climatic variation and human activities at a regional-level over the last 27,000 years. Findings show that temperate and coniferous taxa were dominant before 18 cal kyr BP reflecting the glacial climate. Between 18 and 14 cal kyr BP, thermophilic taxa increased in response to global deglaciation. A notable shift from deciduous to evergreen forests occurred at approximately 14 cal kyr BP, after which pollen concentration increased but pollen diversity decreased. Pollen assemblages indicated dense forests, primarily composed of evergreen oaks developed under warm and strong summer monsoon conditions from 13 to 8 cal kyr BP. High rates of vegetation change occurred during the middle Holocene before vegetation diversity gradually increased during the Holocene Thermal Optimum, with high variability of precipitation in the Yilong Lake region. Anthropogenic forcing progressively became the main factor affecting vegetation composition and vegetation change rates over the past three millennia. • We reported a pollen record from Yilong Lake in Yunnan province, China. • Cold-tolerant taxa dominated before 18 cal kaBP after which thermal-like taxa increased. • Evergreen forests replaced deciduous forests around 14 cal kaBP. • Vegetation change rates peaked in mid-Holocene with mega-thermal but frequent droughts. • Departure of vegetation and potential climax occurred in late-Holocene due to human activities. [ABSTRACT FROM AUTHOR]

Reconstructions of ecosystem dynamics in tropical East Africa during the latest Pleistocene and the Holocene provide important long-term ecological insights, but so far, only a few, sometimes incomplete terrestrial records exist. In this paper, we present a new high-resolution palynological record from the Lake Victoria basin, covering the period from 16,600 to 9000 cal yr BP, when Afromontane forests and tropical rainforests gradually replaced the savanna. We discuss this dataset in the context of published palaeoclimate data, TEX 86 inferred temperature and δD leaf wax inferred precipitation records, to assess long-term ecological successions and their potential causes. By ca. 16,500 cal yr BP, the movement of the Afrotropical rainbelt, not only brought an increase in temperature and moisture into the Lake Victoria basin, but also promoted the spread of arboreal taxa, such as Celtis and Podocarpus, at the expense of the savanna. At that time, fires were prominent in the sparse Afromontane vegetation. Later from ca. 15,500–15,000 cal yr BP, temperature and humidity rose and Afromontane trees such as Olea and Macaranga spread slightly, while grasses were burning in the savanna. During the period from 13,250 to 10,700 cal yr BP, Afromontane vegetation dominated by Olea became more prominent and expanded towards the lowlands where the tropical rainforest or gallery forest established; however, the savanna only marginally retreated. An initial spread of tropical rainforests occurred from ca. 11,500–11,100 cal yr BP during the onset of the Holocene, when temperatures and moisture further increased. Subsequently, between 10,700 and 10,300 cal yr BP the tropical savanna was largely replaced by the tropical rainforest, while the Afromontane forest likely spread to higher elevations, similar to the patterns observed today. Our high-resolution record demonstrates the dynamic response of African tropical ecosystems to major temperature and humidity variations from 16,600 to 9000 cal yr BP, including some of the most important landscape transformations in East Africa in the past 20,000 years. • Lake Victoria's first high–resolution pollen record (latest Pleistocene-Early Holocene). • Afromontane species prominent at lower elevations prior to the onset of the Holocene. • Moisture prevails over temperature in early Holocene's vegetation shifts. • Warm and/or humid conditions favoured both Afromontane and rainforest communities. • Colder or drier periods were associated with savanna grassland vegetation. [ABSTRACT FROM AUTHOR]

A transition from cereal-based agriculture to pastoralism in North China occurred around 3600 cal yr B.P., and corresponded to Northern Hemisphere cooling and the onset of an arid climate over North China. In this paper, we investigate the mechanisms for the ~3600 cal yr B.P. climate transition that may have triggered this change in Chinese civilization based on a compilation of 33 high-resolution paleoclimate records spanning the 4000–3000 cal yr B.P. interval. Results show that North and South China experienced a meridional dipole pattern of the climate change. From 4000 to 3600 cal yr B.P., the region north of 30°N was wet and the region south of 30°N was dry, then from 3600 to 3000 cal yr B.P., the pattern reversed with a drier north and a wetter south. We found that this climate transition was related to the onset of a more El Niño-like state in the tropical Pacific Ocean after ~3600 cal yr B.P., which resulted in more precipitation in South China but less precipitation in North China. Climate in the marginal monsoon areas of North China deteriorated, becoming more cold and arid, and pastoralism replaced cereal agriculture as the dominant mode of subsistence. Our study highlights the important role of the paleo-El Niño-Southern Oscillation (paleo-ENSO) for the evolution of civilization in China. • North China transitioned to pastoralism around 3600 cal yr B.P. • A shift in East Asia's dipole climate pattern was observed at the same period. • This climate change was influenced by the paleo-ENSO. • The paleo-ENSO significantly impacted the progression of Chinese civilization. [ABSTRACT FROM AUTHOR]

Sedimentological studies of ancient fluvial systems commonly do not consider in detail palaeosols in floodplain deposits. This is the case of the upper Paleocene Esplugafreda Formation (Pyrenees, Spain), a 100–340 m thick alluvial succession, in which palaeosols represent more than 80% of its thickness. This unit closely predates the climate crisis of the Paleocene/Eocene transition, the PETM (Paleocene/Eocene Thermal Maximum). The purpose of this paper is to define the palaeoenvironmental conditions of formation of these palaeopedogenic conditions, and to establish possible changes during the late Paleocene directly prior to the onset of the PETM. This paper analyses the palaeosols in terms of variations in 'aquic conditions', concerning to water saturation, reduction and formation of redoximorphic features in soils. The uppermost part of the Esplugafreda Formation consists of cumulative sandy mudstone palaeosols, laterally associated with sparse channel deposits. Two pedotypes were recognised: Pont d'Orrit and Areny. A mud content >60% (mainly montmorillonite), pedogenic slickensides, wedge-shaped aggregates, mukkara and blow structures indicate that both pedotypes belong to the Vertisol order. They reveal a climate characterised by strong seasonal moisture variations. The Pont d'Orrit pedotype, which dominates the lower portion of the succession, shows reddish brown horizons (Bss), calcareous nodules concentration (Bssk horizon) and scarce redoximorphic features, which indicate a semi-arid climate. The Areny pedotype, which prevails in the upper part, shows a yellow horizon (Bssg) containing goethite and abundant redoximorphic features, which reveal aquic conditions. There is no clear sedimentological evidence that river flooding became relatively more frequent in the upper part of the succession, suggesting that the aquic conditions were caused by an increase in precipitation. This study demonstrates that (i) changes in some pedogenic features within the Vertisols enable interpretation of palaeoenvironmental variations and (ii) this region experienced a changing climate in the late Paleocene, before the onset of the PETM. • Paleocene Esplugafreda Formation displays Vertisols with surface-water gley. • Late Paleocene continental alluvial succession records an increase in precipitation. • Floodplain palaeosols record environmental changes hidden in coeval fluvial deposits. [ABSTRACT FROM AUTHOR]

In this paper, the stratigraphic occurrence of n -alkanes (C n) is investigated in three peat cores (Mildred, JPH4 and McMurray) from the ombrotrophic peatlands in northeastern Alberta, Canada, to determine their origin, biomass input, and paleoclimatic significance. The molecular composition of n -alkanes is dominated by the >C 21 medium- to long-chain homologues, with a strong odd over even predominance. A number of n -alkane-based indices (e.g. predominant n -alkane, C 23 /C 29 , C 23 /(C 27 + C 31), P aq , ACL, and CPI), show changing conditions in the organic matter (OM) input from Sphagnum species or terrestrial vascular plants, which increasingly contributed upwards in the peat profiles, and through time. P aq and C 23 /(C 27 + C 31) proxies are similar in the three cores, and allow us to infer vegetation variations that coincide with the climate alternations of the Medieval Warm Period (MWP), Little Ice Age (LIA), and modern Recent Warming (RW). The utilization of ACL-ket and (C 23 + C 25)/(C 27 + C 29 + C 31)-ket proxies, performed in comparison with n -alkane proxies, further support the biomarker-based reconstructions of paleoclimate variations over recent centuries. This study suggests that n -alkane homologues are sensitive to vegetation and climate changes and thus are reliable biomarkers for tracking past shifts in vegetation and climate variations in peat archives. • Determine organic matter source of peat sediments from n -alkane biomarkers. • C 23 /(C 27 +C 31) n -alkane proxy is proposed and can effectively characterize climate changes. • P aq proxy indication could be misleading when the contribution of Sphagnum fuscum to the peat is large. • n -Alkan-2-one proxy is studied to further confirm the biomarker-based reconstruction of paleoclimatic changes. [ABSTRACT FROM AUTHOR]

Abstract The relationship between ungulate stable carbon isotope values and environmental variables (temperature, relative humidity, precipitation) remains poorly understood. In this paper, we evaluate this relationship for, predominantly, C 3 ecosystems in the winter rainfall areas of southern Africa. In our dataset (290 individuals representing 23 species), δ13C values of ungulate enamel are significantly correlated with mean annual precipitation (MAP), moisture index (MI) and summer aridity index (SAI), variables that also influence the distribution of C 3 /C 4 grasses. Our study confirms previous findings that faunal δ13C values in C 3 ecosystems are most strongly correlated with variables related to precipitation. δ13C enamel values for ungulate browsers are more strongly correlated with a larger number of environmental variables than values for grazers and mixed feeders and vary according to vegetation type. We apply regressions derived from the modern dataset to estimate palaeoclimatic shifts based on δ13C enamel values of browsing fauna at the Pleistocene sites of Hoedjiespunt and Elandsfontein in South Africa. Highlights • Ungulate δ13C correlates best with seasonality of rainfall index SAI, as well as MAP and a moisture index. • Browser δ13C values are correlated with (among others) MAP and MAPE. • Meteorological correlates of δ13C ensembles reveal palaeoenvironments. • Correction for palaeo-pCO 2 has a significant impact on the interpretation of fossil δ13C. [ABSTRACT FROM AUTHOR]

Abstract This special issue of Palaeogeography Palaeoclimatology Palaeoecology on "Cenozoic Climate Change in Eastern Asia" contains a series of multidisciplinary studies representing a wide range of research on paleovegetation, sedimentology, clay mineralogy, geochemistry, magnetostratigraphy, and climate modelling. The general significance of these studies is that analysis of terrestrial paleoclimate changes in eastern Asia may offer insights into the effects of Tibetan Plateau uplift, and ultimately the dynamic processes of global change that took hold throughout the Cenozoic. The present volume is Part II of this special issue. The first part of the special issue was dedicated to understanding eastern Asian paleoclimate variation during the Cenozoic by especially evaluating proxy data from geochemistry and climate modeling. Part II includes additional geochemical studies of terrestrial deposits from different regions of eastern Asia as well as climate modeling. Some of these papers focus on the impact or effect of these climatic changes on various floras and faunas in this region. In these studies, the period investigated ranges from the Eocene to the middle Holocene, thus encompassing most of the Cenozoic. Collectively, these studies provide significant new insights into the Cenozoic paleoclimate framework of eastern Asia. [ABSTRACT FROM AUTHOR]

Abstract This special issue provides new studies in the field of Cenozoic climate change in eastern Asia. The papers in this volume are multidisciplinary in nature and examine a range of topics including paleovegetation, sedimentology, clay mineralogy, geochemistry, magnetostratigraphy, and climate modelling. The findings of these studies demonstrate that analysis of terrestrial paleoclimate changes in eastern Asia may offer insights into the effects of Tibetan Plateau uplift, and ultimately the dynamic processes of global change that took hold throughout the Cenozoic. The second part of this special issue, to be published later, will add a paleoecology component, examining how Cenozoic climate change has impacted floras and faunas in eastern Asia. [ABSTRACT FROM AUTHOR]

Abstract The Eocene was an interval of climate evolution, when the extreme high temperatures of the earliest Cenozoic gave way to a global cooling trend. Fine-grained lacustrine sediments of Eocene age from northeastern China represent an excellent archive to study long-term environmental and climatic changes at high-resolution. The Huadian Basin is a Cenozoic, fault-bounded basin in Jilin Province, northeastern China. Though small in area, it contains numerous oil shale- and coal-bearing layers, which provide an abundant Middle to Late Eocene palynoflora. Eighty-five palynomorph genera and one hundred palynomorph species were identified in the Huadian Formation, allowing to distinguish 4 palynozones. The nearest living relatives of the recovered palynomorph taxa suggest the presence of subtropical evergreen and deciduous broad-leaved forests during deposition of the Huadian Formation. Using the coexistence approach (CA), we calculated seven paleoclimatic parameters, which indicate a subtropical warm and humid climate with a mean annual temperature above 13.6 °C and a mean annual precipitation of at least 887 mm. However, the climate became cooler and drier during the transition from the lower Oil Shale Member to the upper Carbonaceous Shale Member. Palaeoclimatic data from the various Middle and Late Eocene basins of northeastern China (i.e., the Huadian, Fushun, Yilan, Hunchun and Jishu basins) were compared with data from North American and European basins. Middle Eocene climate in the Northern Hemisphere was generally warm and humid, and the mean annual temperature and precipitation in northeastern China were similar to those in North America, though slightly lower than those of Europe. Similar trends in temperature and precipitation on different continents support the existence of a global Mid-Eocene cooling event. This paper is the first systematic study of Middle to Late Eocene seasonality in the Huadian Basin. Our results show an apparent differentiation in both temperature and precipitation between summer and winter, supporting the view that the East Asian Monsoon was established in northeastern China already during the Middle to Late Eocene. This Middle and Late Eocene monsoon was likely driven by the development of Pacific trade winds and an alternating, seasonal high- and low-pressure system over Siberia. The climatic changes observed in our dataset, especially the precipitation changes, appear to have played an important role in controlling oil shale formation in the Huadian Basin. A warmer and more humid climate, with abundant precipitation and high subsidence rates, formed a deeper Huadian depositional lake. High productivity and stable stratification provided the abundant organic matter and favorable preservation conditions necessary for oil shale accumulation. Highlights • The Middle-Late Eocene palynoflora were firstly systematically studied in Huadian Basin. • We quantitatively estimated the Middle-Late Eocene climate based on CA method. • A globally cooler phase was recognized in the Middle Eocene. • Climate seasonality in the Middle-Late Eocene supports the EAM was already prevalent in NE China. • Changes in climate, especially precipitation, play an important role in oil shale formation. [ABSTRACT FROM AUTHOR]

Abstract Floral communities in terrestrial habitats such as steppes are highly sensitive to regional climate changes. Here, we generated carbon and nitrogen isotope profiles for soil organic matter (SOM) in the Weinan loess-paleosol section in order to investigate changes in floral communities on the Chinese Loess Plateau (CLP) and their relationship to climate variation since 75 ka. δ13C SOM at Weinan ranges from −23.6 to −18.0‰ and δ15N SOM ranges from +3.4 to +5.5‰. Modeling based on the δ13C SOM record suggests that the proportion of C4 plants (%C4) has varied from lower during cold intervals (with minima of 24–32% at 73.1 ka, 20.9 ka (LGM), and 0.6 ka) to higher during warm intervals (with maxima of 62–64% at 53.0 ka and 8.2 ka). The δ13C SOM and δ15N SOM profiles are strongly correlated (r = +0.82; p(α) <0.001), suggesting that the N-isotope composition of SOM was also largely controlled by inputs of C4 versus C3 plants, consistent with known patterns of N-isotope variation among modern plants. The %C4 profile exhibits significant covariation with reconstructed mean annual temperatures (MAT) (r = +0.42; p(α) <0.001), mean annual precipitation (MAP) (r = +0.42; p(α) <0.001), and summer monsoon intensity (r = +0.50; p(α) <0.001), suggesting that paleovegetation was controlled by each of these climate variables to a degree. Comparing the Weinan record to SOM profiles across the CLP region, we identified three zones of varying monsoonal influence, with the East Asian Summer Monsoon (EASM) exerting the strongest influence on the southeastern margin of the CLP, and the East Asian Winter Monsoon (EAWM) greater influence on its northwestern margin. This paper provides new insights into deciphering paleovegetation patterns and their links to paleoclimate change on the basis of paired C- and N-isotope records. Highlights • Analysis of δ13C and δ15N of soil organics in Weinan section, Chinese Loess Plateau • δ13C SOM and δ15N SOM profiles exhibit strong correspondence since 75 ka • Both C- and N-isotope compositions controlled mainly by inputs of C3 vs C4 plants • Paleovegetation type strongly influenced by summer monsoon intensity [ABSTRACT FROM AUTHOR]

Abstract: In the 2,500,000 km2 Lake Chad Basin in central Africa, the 2000 Shuttle Radar Topographic Mission (SRTM) data have been used to supplement the existing topographic data. SRTM data produce much sharper images of the region''s topography and provide new insights into debates about the nature and extent of late Quaternary Lake Chad. This paper shows that the accuracy of SRTM30, the recently released 30 arc seconds topographic data from SRTM, largely surpasses that of previous global Digital Elevation Models (DEMs) available in the region. Using a GIS we identified from SRTM30 elevation data key features in the landscape topography providing further evidence for the existence of a Megalake Chad. The SRTM30 data corroborate the presence of two ancient shorelines associated with stillstands of the paleolake at the elevation of the Mayo Kebbi and Bahr el Ghazal spillovers. We found a general flattening of the topography in the region covered by Megalake Chad which is most likely the result of wave-cut action. The SRTM30 data show that the remains of the highest paleoshoreline have a constant elevation of 325±5 m amsl. At its maximum extent, Megalake Chad had an area of about 340 000 km2 (only 8% less than the present-day world''s largest lake, the Caspian Sea). The SRTM30 data also revealed ancient drainage networks in the Sahara that lead to Megalake Chad. We compiled available 14C dates to constrain Holocene Megalake Chad events. The results presented in this paper have significant consequences for improving our knowledge of regional paleohydrology and continental climate change. This study is also the first step for a GIS-based reconstruction of late Quaternary paleohydrology in tropical Africa. [Copyright &y& Elsevier]

The 4.2 ka event was a period of global drought and climate cooling linked to the widespread disruption of Neolithic culture. However, the detailed climatic changes during this period are not completely understood. In this paper, we report a high-resolution pollen record for the Dayanghu wetland in the Zhejiang region of southeastern China, which we use to infer mean annual precipitation (MAP) fluctuations during the period spanning 4600–4000 calendar years before present (cal. yr BP). There was a long-term trend of decreasing MAP during this interval, consistent with weakening of the East Asian Summer Monsoon since the mid-Holocene. This trend was punctuated by episodes of relatively high MAP at 4350–4320, ca. 4260, and 4220–4200 cal. yr BP, and extreme droughts at 4200 and 4150 cal. yr BP. We propose that solar activity promoted El Niño events and contributed to dramatic MAP fluctuations in the Dayanghu wetland. La Niña events and negative-phase intervals of the Pacific Decadal Oscillation may have been responsible for the extreme drought at 4200–4150 cal. yr BP. In summary, we propose a close relationship between MAP and solar forcing, with short-term enhanced solar activity increasing the intensity of the East Asian Summer Monsoon and contributing to increasing decadal variability in the inner tropical Pacific, which ultimately leads to increased precipitation variability in southeast China. The results improve our understanding of the detailed climatic features of the 4.2 ka event. • High-resolution pollen record for ca. 4.2 ka for the Zhejiang region, China. • Pollen-based mean annual precipitation was quantitatively reconstructed. • Long-term droughts tended to occur during 4600–4000 cal. yr BP. • La Niña-dominated ENSO contributed to a catastrophic drought at 4200–4150 cal. yr BP. [ABSTRACT FROM AUTHOR]

The abrupt weakening of the East Asian summer monsoon (EASM) during Younger Dryas (YD) has been attributed to freshwater discharge into the North Atlantic ocean and resultant Northern Hemisphere cooling. Recent studies have found that sea ice variability in the Nordic Sea during the YD exerted a great influence upon the northern high-latitude climate. However, the influence of sea ice upon EASM evolution during YD event remains unclear. In this paper, we report two precisely-dated speleothem oxygen isotope records from the EASM-dominated region of central China. Our records archive abrupt changes in EASM variability during the YD event. Initially, there was a significant strengthening of the EASM during the mid-YD following the gradually increased Atlantic meridional overturning circulation (AMOC). Later this trend reversed at ∼12.15 ka due to northern high-latitude sea ice fluctuations and a consequent reduction of AMOC. At the YD termination, abrupt intensification of the EASM was synchronous with the rapid decline of sea-ice and recovery of the AMOC indicating that sea ice variability was a significant influence on high latitude climate and EASM variation during the YD. • A new speleothem δ18O record show significant EASM strengthening during mid-YD. • Mid-YD oscillation in EASM linked with NH sea ice variability. • Abrupt EASM intensification at YD termination synchronous with the rapid decline of sea ice. • Drier interval following the YD termination in central China. [ABSTRACT FROM AUTHOR]

The vegetation history of the central Tibetan Plateau over the last two millennia provides an important baseline for exploring future vegetation evolution. In this paper, we analyze high-resolution records of pollen, grain-size, total organic carbon (TOC) and total nitrogen (TN) for a 66.5 cm deep sediment core collected from Beilei Co on the central Tibetan Plateau. Between ca. 210 CE and 1988 CE, pollen spectra together with other proxies show that the Beilei Co region was covered by alpine steppe and experienced a relatively stable environment, with only slight changes in vegetation composition and minor climatic variations. However, since 1988 CE, abundances of Artemisia and Cyperaceae have begun to increase, while those of Chenopodiaceae (current accepted Latin name is Amaranthaceae) and Asteraceae have decreased sharply. Both the pollen assemblages and other proxies show that the study area is currently undergoing a major change and that the period of vegetation stability that has characterized the past two millenia has now ended. We argue that the recent changes in the vegetation may be caused by increasing precipitation and/or thawing permafrost due to global warming. In the future, the alpine steppe around Beilei Co may be replaced by alpine meadow. • High-resolution pollen spectra covering last two millennia completed for the central Tibetan Plateau. • Vegetation of the central Tibetan Plateau is stable for most of the time until the last few decades. • The central Tibetan Plateau is experiencing an unprecedented phase of wetting. [ABSTRACT FROM AUTHOR]

High-latitude permafrost peatlands are sensitive to global warming, and understanding their paleohydrological evolution is critical for assessing future hydrological and environmental changes. This paper presents a diatom record from a peat deposit covering the past 3300 years to reconstruct the moisture and acidity conditions in the Tuqiang permafrost peatland in the northern Greater Khingan Mountains of northeast China. Our findings are integrated with previously published records of plant macrofossils, palynology, and geochemistry from the same profile. From 3300 to 2800 cal yr BP, planktonic and benthic diatoms were equally abundant, indicating relatively high moisture conditions, while the low abundance of acidophilous diatoms reflects relatively high pH during this interval. Pollen data show dominance by sedges with input from the surrounding Pinus forest, while LOI data and lithology suggest that the site was a non-peat accumulating wetland. During the period 2800–1100 cal yr BP, the dominance of planktonic diatoms indicates a wetter local environment, concurrent with the dominance of peat-forming sedges (Eriophorum), indicating the development of a peatland. Between 1100 and 500 cal yr BP, a short-lived increase in acidophilous diatoms (Eunotia) marks a decrease in pH. Since 500 cal yr BP, the dominance of benthic diatoms reflects a drier environment, while a vegetation shift from an Eriophorum -dominated rich fen to a Sphagnum- and Ericaceae-dominated poor fen. An increase in Eunotia diatoms prior to the Sphagnum peak may indicate that diatoms are more sensitive to local acidified habitats than moss. Peatland development in the northern Greater Khingan Mountains was likely induced by the onset of a cooler and wetter climate starting at approximately 2800 cal yr BP, a scenario supported by regional paleoclimate records. Since 700 cal yr BP, the peatland has been affected by both anthropogenic activities and climatic changes, as a drying climate and intensified human activities around the study area reduced diatom species diversity and peat accumulation. Under the background of future global warming and enhanced human activities, the decreasing species diversity and carbon accumulation rate of peatlands in high-latitude permafrost regions need more attention. • Diatoms can indicate local moisture and acidity in permafrost peatlands. • Diatoms are likely more sensitive to microhabitats than bryophytes. • TQ peatland formed after 2800 cal yr BP caused by the cooler and wetter climate. • Rich-fen shifted to poor-fen which co-influenced by deforestation and dry climate at LIA. [ABSTRACT FROM AUTHOR]

Bösken et al. (2017) aimed at contributing to the environmental variability of the Gravettian population in ‘southeastern’ Europe during the Last Glacial Maximum (LGM) with an interdisciplinary study at the Upper Palaeolithic site Ságvár Lyukas Hill (Hungary). However, the classification of the site as Gravettian is erroneous because the LGM archaeological record of eastern central Europe is composed of findings of another culture, the Epigravettian. This short comment on the paper of Bösken et al. (2017) presents the archaeological chronology between 34 and 16 kyr BP with a focus on the Gravettian–Epigravettian dichotomy. [ABSTRACT FROM AUTHOR]

Climatic oscillations at the Gelasian/Calabrian transition modified terrestrial palaeoenvironmental settings in the European region. A gradual drop in global temperatures beginning about 2.7 Ma led to drier conditions and to a reduction in, and subsequent disappearance of, sub-tropical vegetation in the central Mediterranean area by ca 1.2 Ma. Large ungulates are sensitive to vegetation changes and faced with harsher environmental settings may shift their feeding strategies to exploit available food resources in different ecosystems. In fossil assemblages such dietary adaptations are reflected by tooth morphology (a phylogenetic signal) and tooth wear degree (a direct signal of the species' diet). In this paper, we investigate how large herbivores responded to palaeoenvironmental changes that occurred at the passage between the Gelasian and Calabrian ages in the Italian Peninsula, analysing the dental wear patterns and hypsodonty of the early Pleistocene fossil ungulates assemblage of Olivola (Aulla, Central Italy). We found that while ungulate feeding behaviours during the Gelasian spanned from browsers to grazers, in the locality of Olivola this group of herbivores display a narrower range of diet types with many taxa adopting a mixed feeding behaviour. Cervids in particular, whose fossils are often associated only with wooded environments, as a response to the reduction of covered sub-tropical vegetation, shifted from a strict browsing diet in mostly closed habitats to a more abrasive one taking advantage of the spread of open landscapes. We also provide new data on the feeding behaviour of the rare fossil caprines, Procamptoceras and Gallogoral meneghinii , suggesting a grass-rich mixed diet for the former and a certain degree of dietary plasticity for the latter. Our research thus contributes to the better understanding of how ungulates adapted in the past to exploit different resource types during pivotal climatic changes and how environments changed in Central Italy on the onset of colder and more arid conditions. [ABSTRACT FROM AUTHOR]

The population history of the Adélie penguin ( Pygoscelis adeliae ) and its response to climatic and environmental changes have been widely studied in maritime Antarctica and several glacial refugia of Adélie penguins were dated back to the Last Glacial Maximum. However, the process of colony expansion during the subsequent glacial-interglacial transition was less well-documented. In this paper, we investigate an ornithogenic core from Vestfold Hills, East Antarctica, to improve knowledge of postglacial penguin colonization. Local deglaciation occurred around 15.6 kyr BP, based on a coarse-grained detrital layer, a date that is earlier than most of those reported in other studies from the same region. Geochemical analysis of the core suggests penguins started colonizing the northern Vestfold Hills around 14.6 kyr BP, the oldest geological record in East Antarctica on penguin occupation, and their population exhibited a broadly increasing trend thereafter. The population expanded at approximately 6740 yr BP, in the mid-Holocene, which corresponds to a local climatic optimum. Although this inference is based on population changes of local sub-colonies, it corresponds well to reconstructions of regional climate change, and changes in the penguin population based on genetic studies. From a consideration of the results of previous studies of the occupation history of sea birds following deglaciation in the Arctic, as well as other parts of Antarctica, we propose that sea birds colonized the emerging ice-free areas shortly after local glacier retreat. Over geological time-scales, the availability of breeding habitat is a key factor controlling the population size and activity range of Antarctic Adélie penguins. [ABSTRACT FROM AUTHOR]

In recent decades, southernmost South America (50–56° S) has experienced marked climate change (regional warming, decreased precipitation, reduced snow cover, and increased frequency of heat waves) related to variations in atmospheric circulation over varied timescales. In this paper, we develop oxygen isotopes from tree-ring cellulose (δ18O TRC) as a proxy for climate and atmospheric circulation in order to extend the regional meteorological record to deeper time intervals. Our work focuses on Nothofagus forests in two areas: (i) deciduous N. pumilio forest in the steppe transition zone near Punta Arenas and (ii) humid evergreen N. betuloides forest in the Navarino Island region. To investigate the potential for reconstructing palaeoclimate, δ18O TRC variations were correlated with local climate parameters as well as regional (Amundsen Sea Low, ASL) and hemispheric (Antarctic Oscillation, AAO) atmospheric circulation modes for the last 60 years. N. betuloides δ18O TRC variations show an overall positive trend, indicating isotopic enrichment over the study period, whereas no trend is recorded for the N. pumilio record. The strongest relationships with climate, together with the widest spatial representativeness, occur in the N. betuloides chronology during the growing season (spring to austral summer) and extend spatially from mid to high latitudes. In contrast, the sensitivity of the records is limited to summer months, and spatial correlations are much more limited. In addition, the N. betuloides record shows greater potential for reconstructing local climate features such as soil water (r = − 0.76), wind speed (r = 0.69), and precipitation (r = − 0.66), as well as regional (ASL, r = − 0.80) and hemispheric (AAO, r = 0.77) patterns of extratropical atmospheric circulation. Overall, we conclude that the N. betuloides record represents the most valuable tree-ring climate proxy for southernmost South America over past centuries. • Two annual oxygen isotope (δ18O) records from Nothofagus tree rings in southern South America are established. • Strong climatic signals in δ18O from Nothofagus betuloides and N. pumilio are related to local and regional climatic variations. • Differences in climatic sensitivity among δ18O records are related to species-specific responses and site specificities. • δ18O TRC record of N. betuloides from Navarino Island shows strong relationships with soil water content (r = − 0.76) with regional (ASL, r = − 0.80) and hemispheric (AAO, r = 0.77) extratropical atmospheric circulation. • δ18O TRC records from N. betuloides forests show high potential to reconstruct climate variations during the last 400–500 years. [ABSTRACT FROM AUTHOR]

Geochemical signatures from biogenic carbonates are being increasingly employed as palaeoenvironmental proxies. In turn, many of these proxy archives including mollusc shells, corals, and otoliths have periodic growth structures, which allow the reconstruction of chronologically constrained records of palaeoenvironmental variability at unparalleled high temporal resolution. Studying the growth and chemistry of these periodic growth structures is known as sclerochronology. Biogenic hard parts accumulate in geological or archaeological deposits, and can be directly dated using radiometric and racemisation methods. They therefore offer the opportunity for high-resolution palaeoenvironmental reconstructions across many time intervals, all over the globe. Such data are important for several reasons: (1) understanding past climate and environmental change provides a means of contextualising current and future climate change and ecological disturbance; (2) high-resolution palaeoenvironmental records are essential for constraining, testing and validating global and regional numerical climate models; (3) palaeoenvironmental records from biogenic carbonates can provide an environmental framework from which to understand the behavioural changes and interactions of peoples with their environment. However, inter and intra-species differences in growth rate, physiology, and environmental response can cause variations in the chemical profiles of biogenic carbonates. Before geochemical data is employed for palaeoenvironmental reconstructions, it is thus necessary to examine modern specimens of the target species, or related taxa, to understand how geochemical variations are influenced by local environmental conditions, kinetic and vital effects. This allows the generation of quantitative and more reliable proxy records of environmental change. This special issue brings together the latest research on palaeoenvironmental proxy development and validation in biogenic carbonates. It includes studies on marine, freshwater and estuarine organisms (molluscs, corals and echinoderms), and on traditional as well as novel geochemical proxies. The papers presented here include in situ field calibration studies, laboratory growth experiments as well as methodological studies into the effects of sampling and pre-treatment. The geographical scope is broad, encompassing both the northern and southern hemispheres including South Africa, South America, Australia, Asia, the Mediterranean Sea and the North Atlantic. [ABSTRACT FROM AUTHOR]

Major reorganizations in climate and tectonic regime occurred in East Asia during the Pleistocene, resulting in large-scale environmental changes. In this paper a detailed geochemical and mineralogical record of these changes is presented from a distal alluvial fan sedimentary sequence in the northern Weihe Basin. We established that, in addition to glacial-interglacial variation, there are three distinctly different units deposited over the past 1 m.y. These units are the result of variations in the overall tectonic regime in the northern Weihe Basin. Fine-grained detrital minerals were predominantly delivered during colder climatic periods, whereas evaporative minerals were dominantly deposited during the warmer, interglacial periods, probably as a result of strong seasonal contrast. This compositional variation demonstrates the importance of climate control on hinterland erosion, surface runoff, chemical weathering and evaporation. Al-normalized ratios of indicative major elements relative to average loess composition, indicate important variations in sedimentary processes, mostly related to sediment flux. Si-enrichment is an index for past flooding events, while Fe enrichment, just like K and Ti, reflects influx of clays. In contrast, Ca and Mn are strongly enriched throughout the core, associated with the authigenic precipitation of carbonates, especially during interglacial periods. The lower (~ 1000–690 ka) and upper (~ 330–0 ka) units of the core are characterized by relative intense and frequent flooding, which coincided with extensive ponding in the study area. In the middle unit (~ 690–330 ka) increased salinity levels caused by evaporation, as reflected in the high Sr/Ca ratio and dolomite abundance, led to increased carbonate precipitation. Simultaneously, the increased influx of fine sediments indicates increased clay production in the source area as a result of a more intense summer monsoon strength after 600 ka. [ABSTRACT FROM AUTHOR]

This paper provides a high-resolution temperature reconstruction for the last Millennium from Lake Atnsjøen, SE Norway (61°52′31″N, 10°10′37″E). The sedimentary record reveals strong influence of the large-scale global climate patterns on the local climate in southern part of Eastern Norway. We reconstructed mean July air temperature using Chironomidae-based transfer function and fossil Chironomidae assemblages. The reconstruction was supported by a selection of climate-sensitive geochemical and paleoecological sedimentary proxies of terrestrial and aquatic origin, including Cladocera, pollen and macrofossils. Presented results revealed that summer temperatures were 1–2 °C warmer than the mean Millennial temperatures during the 11th, 13th, 15th and 20th centuries and 1–2 °C lower during the 12th, 14th, 17th–18th centuries. A persistent cold period, the Little Ice Age (LIA), occurred between 1550 and 1800 CE, was interrupted by a short warming at 1650 CE. The recognized regional climate fluctuations during the last Millennium affected the lake and its catchment, of which the strongest impact was caused by the LIA cooling. During the LIA the catchment vegetation was impacted by climate deterioration and the lake productivity reached its lowest level during the last Millennium. The current temperature reconstruction is in agreement with a previous continental scale temperature reconstruction for Europe. From obtained results it emerges that during the LIA the climate of western Scandinavia has been dictated by the atmospheric patterns originating from the North Atlantic. [ABSTRACT FROM AUTHOR]

The Ordovician-Silurian (O S) transition witnessed dramatic tectonic, climatic, marine, and biological coevolution, during which organic-rich black shale was widely deposited and is considered an important source rock. However, the potential links between the differential enrichment pattern of organic matter and climate fluctuations and paleoenvironmental evolution during this period are still unclear. In this paper, the Late Ordovician-early Silurian black shale in a JieLong (JL) section in South China was identified by graptolitic fossils, total organic carbon (TOC) content, X-ray diffraction (XRD), scanning electron microscopy (SEM) and geochemical analysis. The results show that the provenances of sedimentary rocks are all granodiorite-like. According to the variations in the TOC content and geochemical indicators, four layers are delineated. Under warm and humid climatic conditions, sea level rise and unstable seasonal upwelling led to Unit 1 organic matter enrichment controlled by high primary productivity, anoxic conditions and effective smectite production. Unit 2 organic matter burial was controlled by cold, arid and oxic environmental conditions, but primary productivity was still relatively high. After the end of the glacial period, warm and humid climatic conditions and rapid transgression were the main factors affecting the burial of organic matter in Unit 3. Under hot and humid climate conditions, higher terrigenous detrital inputs and unfavourable preservation environments, the dilution of organic matter in Unit 4 was accelerated. The corrected chemical index of alteration (CIA corr) values show that the study area experienced a climate change of alternating cold and warm conditions in response to the climate fluctuation during the glacial-interglacial period. The CIA corr value is negatively correlated with the TOC content, while the generation of available clay minerals (smectite) in warm and humid climates is usually consistent with the enhanced burial flux of organic matter, supporting the important role of climate fluctuations in the accumulation of organic matter. Finally, a comparison of the data from the present study with geochemical data from different profiles in South China reveals the role of climatic fluctuations during the O S transition in controlling paleoenvironmental evolution and organic matter enrichment, while such a heterogeneous factor is usually associated with global or regional geological events. Our study highlights this differential enrichment mechanism as a combined response of multiple factors and provides important implications for glacial-interglacial organic matter enrichment mechanisms. • Rapid changes of weathering indices imply climatic fluctuations during the Late Ordovician-Early Silurian. • Four different patterns were established for organic matter accumulation across the O/S. • Climate fluctuations and the heterogeneity nature of ocean systems explain the regional variations of OM accumulation. [ABSTRACT FROM AUTHOR]

Reconstructing Holocene changes in regional sea level is useful for understanding future sea-level scenarios. In this paper we examined the sedimentology, pollen, foraminifera, and organic matter properties of a well-dated profile from the Subei Basin that spans the last 6.7 ka. By integrating our findings with the archaeological record, we investigated mid- to late Holocene vegetation responses to relative sea-level fluctuations and considered the impact of climatic variations on cultural development. In the middle Holocene, the rapid and abrupt expansion of salt marsh vegetation (Chenopodiaceae, Cyperaceae, and Poaceae) suggests a relative rise in sea level. From 5.7 to 4.2 cal ka BP, lowland swamps were settled by Neolithic communities, as indicated by peak levels of microscopic charcoal and a significant rise in herbaceous pollen species, such as Cyperaceae, Typha , Myriophyllum , and Poaceae. From 4.2 to 3.7 cal ka BP, a major increase in Chenopodiaceae abundance and a δ13C excursion were observed along with a decrease in Cyperaceae and Poaceae levels, which revealed that human activity significantly decreased following the 4.2 ka climate event. Evidence suggests that the area under investigation experienced a relatively high sea level between 6.7 and 6.0 ka, a relative decrease in sea level between 6.0 and 5.7 ka, a steady sea-level condition between 5.7 and 4.2 ka, and gradual replacement by a freshwater marsh between 5.7 and 4.2 ka. The pollen and δ13 C records demonstrate that the relative sea level rose quickly from 4.2 to 3.7 ka, which could correspond to the 4.2 ka event. Enhanced El Niño-Southern Oscillation (ENSO) variance and intense climatic events in eastern China were the driving forces behind the mid-late Holocene relative sea-level shift. The rise in relative sea level eventually led to the collapse of the Qingdun and Jiangzhuang sites in the Subei Basin. Our results provide independent vegetation evidence of the simultaneous changes in relative sea level and variations in climate. • Vegatation and environment changes are investigated from ∼6700 cal a BP. • The significant relative sea-level rise in the Subei Plain during 4.2–3.7 cal ka BP. • The rise in relative sea level led to the collapse of the Qingdun site and Jiangzhuang site in the Subei Basin. [ABSTRACT FROM AUTHOR]

The 8.2 ka BP cooling event is the most prominent and abrupt climate event in the Holocene at mid-to-high latitudes in the Northern Hemisphere. In this paper, we conduct model simulations of vegetation responses to the 8.2 ka BP event over East Asia, and compare them with pollen-based vegetation records. Our results reveal that all major Plant Functional Types responded to the climate changes, but the magnitude, timing, and impact of their responses varied. In addition, it was found that after the 8.2 ka BP climate event the vegetation did not always recover to the state simulated before the perturbation, suggesting that different vegetation compositions may occur under similar climate conditions. Changes in temperature exerted a major influence on the vegetation dynamics in the most high latitude regions, and changes in both temperature and precipitation were responsible for the vegetation changes at mid-to-high-latitudes. Compared with pollen-based vegetation reconstructions, our model simulations generally capture the main features of vegetation responses to the 8.2 ka BP event. Notably, only a relatively small proportion of taxa were climatically sensitive during the 8.2 ka BP cooling in pollen records. Only one high-resolution pollen record indicated that the vegetation did not recover to the pre-perturbed state, showing a different vegetation composition after the 8.2 ka BP event similar to our simulations. Such different vegetation compositions could be a long-lasting effect of abrupt climate changes on vegetation through eco-physiological and ecosystem demographic processes, e.g., plant competition. Moreover, our model simulations suggest a more pronounced vegetation responses to the severe cooling in the north and weaker responses to less cooling in the south. Since significant vegetation responses during this event were only seen in few records, more high-resolution pollen records and simulations in terms of vegetation responses to different abrupt climate changes are needed in future. • All dominant PFTs over East Asia responded to the 8.2 ka BP event, but their magnitude, timing, and impact factors vary. • Temperature domain northern vegetation dynamics; temperature and precipitation drive vegetation changes at mid-latitudes. • Simulations agree with pollen-based vegetation responses, but long-lasting effects can only be seen in few pollen records. [ABSTRACT FROM AUTHOR]

In this paper, we use palynology and geochemical proxies to reconstruct late Quaternary vegetation changes within the hydrographic basin of Parnaíba, Northeast Brazil, over the last 130 kyrs. Findings are based on the analysis of a marine sediment core (GL-1248) retrieved from the western equatorial Atlantic (0°55.2′S, 43°24.1′W), close to the coast. Geochemical proxies (Fe/K ratio and Ɛ Nd) indicative of soil erosion match changes in reconstructed vegetation, suggesting a dynamic pattern of hydrological disturbances and ecosystem evolution. Given that reconstructed vegetation does not present the same response to precipitation anomalies on the millennial scale, we sought the main drivers of vegetation changes in the Parnaíba watershed. Results indicate that vegetation succession was primarily influenced by austral insolation from March to May, which triggered changes in the pioneer vegetation types. Our study improves the knowledge of tropical vegetation dynamics in an orbital framework, suggesting 23-kyr precessional cycles as the main driver of landscape evolution in Northeast (NE) Brazil. We also infer that such past climate change events may have been a key causal factor of the high biodiversity of the Neotropics, mediated through the biological exchange of the Amazon and Atlantic rainforest species via ecological forest corridors in the semi-arid Northeast Brazil. • We discuss vegetation change and how it reflects hydrological changes within the Parnaíba Basin, northeastern (NE) Brazil, over the past 130 kyrs • Geochemical proxies (Fe/K ratio and ƐNd) in core GL-1248 are synchronous with reconstructed vegetation patterns, highlighting periods of enhanced or reduced local soil erosion during hydrological disturbances • We define three major vegetation groups (tropical dry forest, lowland rainforest, and wetland), and the discrepancy in water requirements between tropical dry forests and lowland rainforests is discussed • Analysis of the hydroclimatic mechanisms in NE Brazil that triggered the succession of vegetation during glacial phases is discussed [ABSTRACT FROM AUTHOR]

This paper presents the first continuous pollen record from the southern Namib Desert spanning the last 50,000 years. Obtained from rock hyrax middens found near the town of Pella, South Africa, these data are used to reconstruct vegetation change and quantitative estimates of temperature and aridity. Results indicate that the last glacial period was characterised by increased water availability at the site relative to the Holocene. Changes in temperature and potential evapotranspiration appear to have played a significant role in determining the hydrologic balance. The record can be considered in two sections: 1) the last glacial period, when low temperatures favoured the development of more mesic Nama-Karoo vegetation at the site, with periods of increased humidity concurrent with increased coastal upwelling, both responding to lower global/regional temperatures; and 2) the Holocene, during which time high temperatures and potential evapotranspiration resulted in increased aridity and an expansion of the Desert Biome. During this latter period, increases in upwelling intensity created drier conditions at the site. Considered in the context of discussions of forcing mechanisms of regional climate change and environmental dynamics, the results from Pella stand in clear contrast with many inferences of terrestrial environmental change derived from regional marine records. Observations of a strong precessional signal and interpretations of increased humidity during phases of high local summer insolation in the marine records are not consistent with the data from Pella. Similarly, while high percentages of Restionaceae pollen has been observed in marine sediments during the last glacial period, they do not exceed 1% of the assemblage from Pella, indicating that no significant expansion of the Fynbos Biome has occurred during the last 50,000 years. These findings pose interesting questions regarding the nature of environmental change in southwestern Africa, and the significance of the diverse records that have been obtained from the region. [ABSTRACT FROM AUTHOR]

Community level ecology is considered to support significantly the recognition of the ecological status of plant taxa and the identification of plant ecogroups, thus it generally provides extended data sets on the spatial and temporal changes of ecological factors. Since research based exclusively on plant structure and their supposed adaptation to the environment is now considered inadequate, statistical methods can be used. Assuming that co-occurrence of plant fossils on a single hand specimen in the case of autochthonous or parautochthonous floras is the result of their growth in the same phytocenosis, quantitative ecological analysis on Mesozoic materials would yield significant insights. In this paper, statistical and multivariate quantitative analyses of Early Jurassic plant fossil records from the Steierdorf Formation in Anina (South Carpathians, Romania) are presented. Four palaeoecological groups of taxa were distinguished by principal component analysis (PCA) and interpreted as plant assemblages of various palaeobiotopes associated with the sedimentary facies of the enclosing formation. A group of samples was analysed using the principal coordinate (PCO) method and the statistical significance ( p {less than or equal to} 0.05) ( p ≤ 0.05) of individual binary responses of taxa along the first two PCO ordination axes was tested by general linear model (GLM). They revealed putative palaeoecological gradients: axis 1 – disturbance caused by water level fluctuations, axis 2 – temperature, corresponding with the already assumed environmental and climatic change at the Hettangian/Sinemurian boundary. Multivariate analyses enabled the identification of palaeoecological groups and thus inferring palaeogeographical conditions based on Mesozoic materials. [ABSTRACT FROM AUTHOR]

The Tajikistan (TJ) loess has great significance for the study of Quaternary climate changes and dust source in Central Asia. In this paper, we investigate the geochemical composition and provenance of loess. Our results show that the major elements, in order from high to low average content, are SiO 2 > Al 2 O 3 > CaO > Fe 2 O 3 > MgO > K 2 O > Na 2 O > TiO 2 > P 2 O 5 > MnO. Fe, Ti, P and Mn contents in loess are similar to those in the UCC, as is the case with Si, Al and Mg contents in paleosols. Ca is distinctly enriched in loess, and Si, Al and K are depleted. Na is depleted in both loess and paleosols, and P is depleted only in paleosols. In contrast to the UCC, paleosols show enrichments in all trace elements except for Ba, Sr and Zr, but in loess, some trace elements (e.g., Ba, Co, Ni and Zr) show depletion. The CIA value of TJ loess is lower than that of Kashmir loess, the latter being influenced by differences in the sorting and tectonic environment. There are no great changes about provenance during the formation of TJ loess, and the deposit areas have a shorter distance to the provenance. Geochemical data and atmospheric circulations demonstrate that the TJ loess was mainly transported by the near-surface northerly or northwesterly winds, but there may be an additional and local source making a certain contribution to the formation of loess deposits in the south of Tianshan. [ABSTRACT FROM AUTHOR]

The major states, in which Earth's climate operates, i.e., icehouse, greenhouse and hothouse, are epochs of tens of millions of years. These states set long-term boundary conditions that need to be considered for climate and sea-level interpretations. This paper summarizes the conceptual models for hydrological cycling derived from the characteristics of these three climate states. While glacio-eustatic forcing of sea-level changes under icehouse climate conditions is fairly well understood, the drivers of eustatic sea-level fluctuations under greenhouse conditions remain enigmatic. This lack of understanding may be related to incoherencies in the current ideas about the impact of accelerated hydrological cycling on sea level under greenhouse climate conditions. As an example for a greenhouse climate, we review evidences that link proxies for climate and sea level for the intensely studied, but controversially discussed, mid-Cretaceous sea-level history. Based on sequence stratigraphy and a recently published high-precision timescale, we demonstrate that the late Middle Turonian Pewsey δ 13 C isotope maximum represents a major transgression, not a regression as previously stated, which conflicts with the interpretation of a co-occurring δ 18 O maximum to reflect a short glacial episode. This contradiction can be solved by the concept, presented here, that dominance of aquifer-eustasy characterized sea-level forcing during the Turonian greenhouse climate, despite a possible, though contentious, sporadic presence of minor ice sheets. The effects of temperature and ice volume both lead to a pronounced δ 18 O carb maximum during glacio-eustatic regressions. In contrast, the opposing effects of temperature and groundwater volume on oxygen-isotope fractionation lead to a δ 18 O carb maximum during aquifer-eustatic transgressions. We suggest that, throughout Earth history, both aquifer-eustatic and glacio-eustatic forcing formed a combined sea-level response, with dominance of aquifer-eustasy being typical for the greenhouse climate mode. During the icehouse mode, aquifer-eustasy apparently remains active as a background process, but is outpaced by the glacio-eustatic effect. [ABSTRACT FROM AUTHOR]

Studies dealing with the reconstruction of Holocene climate change of tropical areas are scarce. Of these, multi-proxy investigations using peatlands are still absent. In this paper, we present the Holocene record of environmental changes in central–eastern Brazil reconstructed from a core sampled in Pau de Fruta mire (Serra do Espinhaço Meridional, Brazil). We combined palynological and geochemical analyses, supported by core stratigraphy, 14 C dating and multivariate statistics. The location of the mire is ideal because it is in an area which is directly associated with the South Atlantic Convergence Zone (SACZ). Six main phases of change suggested by vegetation and local and regional landscape dynamics were described. In phase I (~ 10,000–7360 cal. yr BP) the climate was very wet and cold and was accompanied by soil instability in the mire catchment (severe local erosion) and the 8.2 ka event was easily recognizable by a large increase in the deposition of regional dust. Phase II (~ 7360–4200 cal. yr BP) was characterized by wet and warm conditions, catchment soil stability and enhanced deposition of regional dust. In phase III (~ 4200–2200 cal. yr BP), climate was dry and warm and soil erosion in the catchment increased again. In phase IV (~ 2200–1160 cal. yr BP) dry and punctuated cooling was reconstructed, together with enhanced deposition of regional dust. Phase V (~ 1160–400 cal. yr BP) reflects sub-humid climatic conditions (like the current climate), the lowest inputs of local and regional dust and the largest accumulation of peat in the mire. While in phase VI (< ~ 400 cal. yr BP) sub-humid conditions continued but both local and regional erosion significantly increased. Our results demonstrate that the tropical peatlands of Serra do Espinhaço Meridional contain relevant records of Holocene climate changes, and that a multi-proxy approach offers good opportunities for a detailed reconstruction of palaeoenvironments. [ABSTRACT FROM AUTHOR]

The southeastern coastal region of China has coastal sand dunes, which are usually called paleo-sand dunes or "Old Red Sandstone". The ages and geological implications of these coastal dunes have been studied for tens of years but are still controversial. In this paper, we used optically stimulated luminescence (OSL) dating to establish the chronology of the paleo-aeolian reddish sand dunes from two representative sites in the coastal region of SE China. Our results indicate that the sand dunes were mainly accumulated in three periods, including 9–6 ka (broadly corresponding to marine isotope stage (MIS) 1), 50–26 ka (MIS 3), and 110–74 ka (MIS 5). Based on the comparison between the regional aeolian dune records and the global sea-level fluctuations, we concluded that the reddish sand dunes were associated with the aeolian processes during interglacials and interstadials when sea-level were relatively higher compared with glacial maxima. We proposed a conceptual model to interpret the formation of the coastal sand dunes. We suggest that coastal dunes that formed during the glacial maxima could not be preserved in highstands above the present sea-level due to the lower altitude of sand dunes and the erosion by water waves during the subsequent marine transgression. Therefore, only aeolian sand dunes accumulated in higher altitudes during sea-level rise were preserved as in the coastal region of SE China. • Luminescence dating of coastal dunes in SE China • Dune sands were mainly accumulated in MIS 1, MIS 3, and MIS 5. • Interplay between exposure of continental shelf and aeolian processes [ABSTRACT FROM AUTHOR]

This paper presents a new palynological record from a 146 cm long finely laminated sediment core obtained in 2009 from the deep-water meromictic Lake Shira (54°30′38″N, 90°12″09′E; ca. 353 m a.s.l.) situated in the Khakassian steppe region of southern Siberia between the rivers Ob' and Yenisei. The area is rich in lakes and represents an exceptionally well preserved sequence of Bronze and Iron Age archeological cultures. Little is known about the changes in vegetation and climate of the region during the Holocene. The palynological analysis of the core allows us to partly fill up this gap in current knowledge. The record of pollen and non-pollen palynomorphs presented here covers the past 2450 year interval with an average resolution of 22 years. The results obtained support the interpretation that the late Holocene vegetation changes around Lake Shira are mainly associated with large-scale atmospheric circulation processes controlling the regional water balance rather than with human activities. An attempt to trace human impact in the pollen assemblages provides no clear evidence for anthropogenic activity, except for the last few decades since ca. 1955, though the region has a long history of mobile pastoralists. For explanation of decadal-scale changes in the regional vegetation cover, the Artemisia /Chenopodiaceae (A/C) pollen ratio proved to be a reliable indicator of effective moisture availability. Using available fossil and published instrumental data our study suggests a link between the North Atlantic warmer/colder temperatures and higher/lower atmospheric precipitation (or moisture availability) in southern Siberia at multi-decadal to centennial scales. [ABSTRACT FROM AUTHOR]

In the present paper we report the most complete fossil avifauna from the southern cone of South America. The specimens here described were collected in the Paso Otero locality, at the middle stream of the Quequén Grande River, Pampean Region (Buenos Aires Province, Argentina). The fossiliferous levels belong to the La Chumbiada Member of Luján Formation (37,800 ± 2300 yr BP, late Pleistocene). The assemblage is represented by 60 specimens belonging to at least 22 taxa. The radiocarbon age indicates that Paso Otero birds represent the oldest late Pleistocene avifauna known from the South American continent and the first coming from a clear interstadial event (MIS3). Available evidence indicates similar environmental conditions during the MIS3 interstadial in the Pampean Region of Argentina and the post-Last Glacial Maximum stadials in southeastern Brazil. The absence of significant extinction events in the latest Pleistocene–early Holocene avifaunas of Brazil and Argentina suggests that the main avifaunal composition along southeastern continental lowlands may not be affected by the cyclic retraction and extension of open environments. On the contrary, the fossil record of Peru and Ecuador demonstrates that a large number of taxa, including aquatic and predatory-scavenger birds, have gone extinct along Andean environments at the Pacific coast, and late Pleistocene climatic oscillations may have played a more dramatic impact in these avian communities. [ABSTRACT FROM AUTHOR]