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Much work has been done to study the behaviour of long-runout landslides and their associated longitudinal ridges, yet the origin of the hypermobility of such landslides and the formation mechanism of longitudinal ridges are poorly understood. As terrestrial long-runout landslides emplaced on glaciers commonly exhibit longitudinal ridges, the presence of these landforms has been used to infer the presence of ice on Mars, where hundreds of well-preserved long-runout landslides with longitudinal ridges are found. However, the presence of the same landforms in regions where extensive glaciations did not occur, for instance, on the Moon and in the Atacama region on Earth, suggests that ice is not the only factor influencing the formation of long-runout landslides with longitudinal ridges. Iceland is a unique region for its high spatial density of well-preserved long-runout landslides with longitudinal ridges. Here, we compiled the first catalogue of Icelandic long-runout landslides with longitudinal ridges, and we compared them with Martian long-runout landslides with longitudinal ridges of similar length. Moreover, we present detailed morphological observations of the Dalvík landslide deposit, in the Tröllaskagi peninsula, Iceland, and compare them with morphological observations of Martian landslides. Our results show that Icelandic long-runout landslides share key features with Martian analogue deposits, including splitting of longitudinal ridges and development of associated en echelon features. Therefore, Icelandic long-runout landslides with longitudinal ridges represent good morphological analogues of Martian long-runout landslides. Moreover, Iceland offers an opportunity to investigate the occurrence of these landforms at a regional scale, as well as their link with deglaciation following the Last Glacial Maximum, which could also provide insights into Martian palaeoclimatic and palaeoenvironmental conditions. [ABSTRACT FROM AUTHOR]

Speleothem δ13C in monsoonal China differs from speleothem δ18O, which is widely used as a climatic proxy for several complex control reasons. Nevertheless, δ13C records have the potential to reveal the implications of hydroclimatic changes. This study reports a speleothem δ13C record from Didonghe (DDH) Cave in central China spanning 34 to 13 kyr BP. After we investigated the factors that influence speleothem δ13C, we found that the δ13C record showed that DDH Cave can prompt directional shifts via local hydroclimatic changes, such as in vegetation types, biomass, and rock–water interaction processes, suggesting that δ13C is mainly controlled by the local hydroclimate. Ensemble empirical mode decomposition (EEMD) results revealed a coupling relationship between δ18O and δ13C on multiple timescales, which suggested that changes in precipitation caused by large-scale monsoonal circulation are controlled by regional hydrological conditions to a great extent. However, the hydrological conditions of the cave were relatively mild and humid during the last glacial maximum (LGM), which revealed the impact of evaporation on changes in the region's hydrological conditions. We also found that the δ18O and δ13C profiles decoupled when δ13C changed with a shift in the location of the westerly during HS1. The δ13C record correlates well with other paleoclimate records, suggesting that regional hydrological conditions are also modulated by the Earth's internal and external driving factors. [ABSTRACT FROM AUTHOR]

Aims Location Taxon Methods Results Main Conclusions Glacial retreat at the end of the Pleistocene epoch opened vast expanses of emergent habitat in the northern hemisphere that were colonized by opportunistic taxa. However, species that undergo post‐glacial expansion may have originated from one or several glacial refugia. We inferred the post‐glacial expansion history of the Eastern Red‐backed Salamander (Plethodon cinereus), a fully terrestrial species with a vast distribution despite severe dispersal limitations. Previous studies indicated populations south of the glacial boundary at the eastern and western limits of the distribution were closely related, suggesting either multiple refugia or an extraordinary post‐glacial expansion event.Eastern North America.Plethodon cinereus (Green, 1818), Caudata: Plethodontidae.We collected ddRAD‐seq data from 106 individuals throughout the distribution of P. cinereus. We estimated phylogeographic structure, including finer‐scale structure among the post‐glacial populations. To test the origins and routes of colonization, we used ecological niche modelling, population trees and analyses of directional range expansion.Analyses supported our hypothesis of a southeastern glacial refugium, with northward expansion along the Eastern Seaboard prior to westward invasion into the Great Lakes region, including southwestern expansion into unglaciated areas at the western end of the distribution. However, a distinct subgroup in the northwestern portion of the range raises the possibility of a second refugium near the ice‐free Driftless Area.Based on our results, we hypothesize a southeastern refugium from which most of today's northern populations undertook extensive post‐glacial colonization. Our results indicate a geographically non‐linear colonization history for P. cinereus. [ABSTRACT FROM AUTHOR]

Aim: Combining different biodiversity dimensions can reveal new diversity patterns disclosing the relative roles of historical, environmental and anthropogenic factors in shaping global seed plant diversity. Location: Global. Time period: Present. Major taxa studied: Vascular plants. Methods: We collated a database encompassing taxonomic (249,000 species), functional and phylogenetic information (34,694 species) of seed plants across different regions of the world. Species richness in each region was weighted accounting for their phylogenetic and functional distinctiveness, obtaining a new metric—μ‐diversity—which was modelled to disentangle the relative roles of historical factors such as climate variability since the Last Glacial Maximum (LGM), environmental features (e.g. actual evapotranspiration—AET) and anthropogenic factors (past and current). Results: Higher μ‐diversity was observed in Papuasia, South East Asia, Australia and Central America, whereas the lowest values were primarily located in the Northern Hemisphere. Climate variability and AET were the most important determinants of μ‐diversity and individual diversity facets, whereas the importance of past human impacts (i.e. the onset of pastoralism) equated or exceeded those of the present ones. Main conclusions: Our integrative approach proved more sensitive in describing species diversity patterns. Few areas on Earth host high and unique proportions of multiple diversity facets and individual diversity facets contribute differently to μ‐diversity across continents. Historical climate stability and water‐energy dynamics strongly affect species diversity, but we also observed that past land‐use legacy may have influenced current plant diversity, which is under intense anthropogenic pressure, especially in Asia as well as in Central and South America. [ABSTRACT FROM AUTHOR]

Scots pine (Pinus sylvestris L.) is one of the most important tree species of the temperate and boreal zones in Eurasia. Its wide distribution range and current patterns of genetic variation have been influenced by Quaternary climatic oscillations and the demographic processes connected to them. In order to better understand the relationship between evolutionary history and demographic factors in a widespread species with a large genome, we used the single‐nucleotide polymorphism (SNP) array to genotype thousands of SNP markers across 62 natural populations (N = 686 trees) of Scots pine in Eurasia. This provides the largest range‐wide SNPs' genetic diversity assessment of Scots pine to date. Our findings show evidence of past admixture events between genetic clusters that were retained despite the potential for effective pollen‐mediated gene flow across the species' distribution range. We also examined the contemporary population structure of the species and analyzed the range‐wide genetic diversity patterns. Phylogenetic analyses and demographic modeling suggest that the observed divergence patterns between genetic lineages likely predate the last glaciation events. Two of the most distinctive groups are represented by trees from the eastern parts of Fennoscandia and Eastern Russia, which have remained separated since the mid‐Pleistocene. The patterns of genetic variation also confirm the dual colonization of Fennoscandia and the existence of an admixture zone in Central Europe that was formed during multiple waves of postglacial recolonization. This study provides insights into the genetic relationships of Scots pine populations from Europe and Asia and offers a more comprehensive understanding of the species' history. Highlights: •A range‐wide population genomic study of important highly outcrossing and wind‐dispersed Eurasian conifer (Pinus sylvestris) was carried out.•The signature of distinct genetic lineages was maintained across populations despite putative efficient gene flow.•Patterns of spatial genetic variation were shaped long before the Last Glacial Maximum. [ABSTRACT FROM AUTHOR]

Having a comprehensive understanding of genetic differentiation, responses to environmental change and demographic history is critical for genetic improvement and conservation efforts. Forest trees are an excellent resource for understanding population differentiation and adaptive genetic variation due to their ability to adapt to different climates and environments. Cephalotaxus oliveri is a relict conifer endemic to China. In this study, we generated transcriptome data and identified 17 728 high‐quality single‐nucleotide polymorphisms (SNPs) from 18 populations. We found significant negative correlations between expression diversity and nucleotide diversity within and among populations, suggesting that gene expression and nucleotide diversity have a reciprocal relationship when the species adapts to the environment. The analyses of population structure showed that C. oliveri displayed a striking genetic structure with four groups. BayeScEnv and RDA methods detected the signatures of local adaptation, and identified that 738 outlier SNPs were associated with precipitation, temperature and soil conditions across heterogeneous environmental conditions. Approximate Bayesian computation analyses showed that the first and second divergence occurred in the late Miocene (c. 10.075 million years ago [Ma]) and the middle Pleistocene transition (c. 0.815 Ma), respectively. Ecological niche modeling of C. oliveri revealed signs of westward expansion after the last glacial maximum, while it was predicted to experience significant range contractions in future climate change scenarios. Geographical factors and environmental factors in southern China have played a critical role in establishing the current genetic diversity and population structure of C. oliveri. This study provides an important reference for forest resource management and conservation for C. oliveri. [ABSTRACT FROM AUTHOR]

The main objective of this study is to investigate the spatial–temporal variability and climate forcing influence during the last 21,000 years of the South American Monsoon System (SAMS) and its components. TraCE-21k simulations, including Full and Single Forcings experiments, were employed. The identification of spatial variability patterns associated with the core of the monsoon region (SAMS) and the South Atlantic Convergence Zone (SACZ), the main components of SAMS during the austral summer, is based on multivariate EOF analysis (precipitation, humidity, zonal and meridional wind). This analysis produces two main modes: the first one is the South American Large Scale Monsoon Index (LISAM), representing the primary oscillation mode for SAMS, and the second one is the SACZ mode, representing the SACZ oceanic portion variability. The TraCE-21k EOF modes demonstrated the ability to represent the SAMS and SACZ patterns when compared to the 20th Century reanalysis. LISAM time series proved to be an important tool for identifying monsoon precipitation variability, consistent with the regime changes recorded in climatic proxies. The freshwater pulses forcing in TraCE-21k are a determining factor for the observed changes in the precipitation regime, mainly during the periods between Heinrich Stadial 1 and the Younger Dryas. The results indicate that the observed and modeled SACZ southward shift in the Late Holocene is primarily modulated by insolation changes, with a stronger correlation observed since the Mid-Holocene period. Through wavelet analysis, it was noted that energy was transferred from low frequencies to high frequencies during the Bølling–Allerød period for the full forcing and freshwater pulse experiments in the Northern Hemisphere. The SAMS multidecadal variability increased from the early Holocene with direct influences of orbital forcing and ice cover. [ABSTRACT FROM AUTHOR]

Premise: Shared geographical patterns of population genetic variation among related species is a powerful means to identify the historical events that drive diversification. The Sphagnum capillifolium complex is a group of closely related peat mosses within the Sphagnum subgenus Acutifolia and contains several circumboreal species whose ranges encompass both glaciated and unglaciated regions across the northern hemisphere. In this paper, we (1) inferred the phylogeny of subg. Acutifolia and (2) investigated patterns of population structure and genetic diversity among five circumboreal species within the S. capillifolium complex. Methods: We generated RAD sequencing data from most species of the subg. Acutifolia and samples from across the distribution ranges of circumboreal species within the S. capillifolium complex. Results: We resolved at least 14 phylogenetic clusters within the S. capillifolium complex. Five circumboreal species show some common patterns: One population system comprises plants in eastern North America and Europe, and another comprises plants in the Pacific Northwest or around the Beringian and Arctic regions. Alaska appears to be a hotspot for genetic admixture, genetic diversity, and sometimes endemic subclades. Conclusions: Our results support the hypothesis that populations of five circumboreal species within the S. capillifolium complex survived in multiple refugia during the last glacial maximum. Long‐distance dispersal out of refugia, population bottlenecks, and possible adaptations to conditions unique to each refugium could have contributed to current geographic patterns. These results indicate the important role of historical events in shaping the complex population structure of plants with broad distribution ranges. [ABSTRACT FROM AUTHOR]

Premise: Quaternary climatic fluctuations and long‐distance seed dispersal across the sea are critical factors affecting the distribution of coastal plants, but the spatiotemporal nature of population expansion and distribution change of East Asian coastal plants during this period are rarely examined. To explore this process, we investigated the genome‐wide phylogenetic patterns of Euphorbia jolkinii Boiss. (Euphorbiaceae), which grows widely on littoral areas of Japan, Korea, and Taiwan. Methods: We used plastome sequences and genome‐wide single nucleotide polymorphisms in samples across the species range to reveal phylogeographic patterns and spatiotemporal distributional changes. We conducted ecological niche modeling for the present and the last glacial maximum (LGM). Results: Genetic differentiation was observed between the northern and southern populations of E. jolkinii, separated by the major biogeographic boundary, the Tokara Gap. These two groups of populations differentiated during the glacial period and subsequently intermingled in the intermorainic areas of the central Ryukyu Islands after the LGM. Ecological niche models suggested that the potential range of E. jolkinii was restricted to southern Kyushu; however, it was widespread in the southern Ryukyu Islands and Taiwan during the LGM. Conclusions: This study provides evidence of genetic differentiation among coastal plant populations separated by the prominent biogeographical boundary. Although coastal plants are typically expected to maintain population connectivity through sea‐drifted seed dispersal, our findings suggest that genetic differences may arise because of a combination of limited gene flow and changes in climate during the glacial period. [ABSTRACT FROM AUTHOR]

In alpine ecosystems, elevation broadly functions as a steep thermal gradient, with plant communities exposed to regular fluctuations in hot and cold temperatures. These conditions lead to selective filtering, potentially contributing to species-level variation in thermal tolerance and population-level genetic divergence. Few studies have explored the breadth of alpine plant thermal tolerances across a thermal gradient or the underlying genetic variation thereof. We measured photosystem heat (Tcrit-hot) and cold (Tcrit-cold) thresholds of ten Australian alpine species across elevation gradients and characterised their neutral genetic variation. To reveal the biogeographical drivers of present-day genetic signatures, we also reconstructed temporal changes in habitat suitability across potential distributional ranges. We found intraspecific variation in thermal thresholds, but this was not associated with elevation, nor underpinned by genetic differentiation on a local scale. Instead, regional population differentiation and considerable homozygosity within populations may, in part, be driven by distributional contractions, long-term persistence, and migrations following habitat suitability. Our habitat suitability models suggest that cool-climate-distributed alpine plants may be threatened by a warming climate. Yet, the observed wide thermal tolerances did not reflect this vulnerability. Conservation efforts should seek to understand variations in species-level thermal tolerance across alpine microclimates. [ABSTRACT FROM AUTHOR]

Marine radiocarbon (14 C) is widely used to trace deep-ocean circulation, providing insight into the atmosphere–ocean exchange of CO 2 during the last deglaciation. Evidence shows a significantly depleted Δ14 C in the glacial deep ocean, suggesting an increased ventilation age at the Last Glacial Maximum (LGM). In this study, using two transient simulations with tracers of 14 C and ideal age (IAGE), we found that the oldest ventilation age is not observed at the LGM. In contrast, the models show a modestly younger ventilation age during the LGM compared to the present day. The global mean ventilation ages averaged below 1 km are approximately 800 (630) years and 930 (2000) years at the LGM and in the present day, respectively, in two simulations. This younger glacial ventilation age is mainly caused by the stronger glacial Antarctic Bottom Water (AABW) transport associated with sea ice expansion. Notably, the ocean ventilation age is significantly older predominantly in the deep Pacific during deglaciation compared to the age at the LGM, with global mean ventilation ages peaking at 1900 and 2200 years around 14–12 ka in two simulations, primarily due to the weakening of AABW transport. [ABSTRACT FROM AUTHOR]

Climate is a key driver shaping the distribution pattern of organisms. Cenozoic climate change has led to extensive biota turnover. Untangling the distribution dynamics of a representative lineage of flora can provide deep insights into biodiversity conservation. Diplopanax is a notable relict lineage of the Tertiary mastixioid flora with abundant fossils in the Northern Hemisphere. Diplopanax stachyanthus Hand.-Mazz. is a representative relic lineage of the mastixioid flora, which was once widespread in the Northern Hemisphere of the early Tertiary period, but with only endemic distribution in the (sub)tropical humid forests of East Asia. It offers a unique chance to understand how climatic drivers shape the Boreotropical flora. In this research, we investigated the distribution dynamics of D. stachyanthus at the last glacial maximum (LGM), mid-Holocene (MH), current, and three periods of the future (2041–2060, 2061–2080, and 2081–2100) at four shared socio-economic emissions scenarios pathways. Our results indicated that the Precipitation of the Wettest Quarter (32.6%), the Precipitation of the Driest Quarter (21.2%), and the Precipitation of the Coldest Quarter (17.3%) are the key factors affecting its distribution. The current high suitable distribution areas are primarily in southern China and northern Indo-China. The enforced winter monsoon seasons in East Asia since the late Pliocene period are the key climatic drivers reducing its once widespread distribution in the Northern Hemisphere. Under future scenarios, centroid transfer analysis suggests that its distribution center will shift southwestward, but the potentially suitable habitats in the coastal regions of southern China and northern Indo-China will be lost. These coastal populations should be prioritized for ex situ conservation. Expanding the nature reserve within its long-term stable distribution range in southwest China is an effective strategy for the in situ conservation of the ancient mastixioid flora. [ABSTRACT FROM AUTHOR]

The extent, chronology and dynamics of the pre‐Marine Isotope Stage (MIS) 2 last British–Irish Ice Sheet (BIIS) are not well known. Although the BRITICE‐CHRONO Project has detailed the maximum extent and retreat phases of the last BIIS for the period after 30 ka and into the Last Glacial Maximum (LGM), the Project identified several pre‐existing datasets and generated new data that implied glaciation pre‐dating the LGM but which post‐dated the Last Interglacial (Eemian; MIS5e); these data are reviewed here. There are no dated till units but are other indicators clearly indicative of glaciation: deep‐sea ice‐rafted detritus flux into the adjacent NE Atlantic, cosmogenic rock‐exposure age dating from glaciated surfaces in Wales and the island of Lundy (Bristol Channel), and optically stimulated luminescence (OSL) ages of proximal glacifluvial sequences on the Isle of Lewis (Outer Hebrides) and in the Cheshire Basin. Taken together these indicate BIIS inception during MIS5d, growth into MIS4 and evidence for dynamic retreat–advance phases during MIS3. OSL evidence for high relative sea level indicated by raised beaches in southern Ireland during MIS4 and 3 at a time of lowered glacio‐eustatic sea level indicates substantial glacial isostatic loading, explained by the early growth of the BIIS during the last cold stage. High relative sea level during MIS4 and 3 coincident with adjacent calving ice sheet margins provides an explanation for the rafted giant erratics found around the shores of southern Britain and Ireland. [ABSTRACT FROM AUTHOR]

We present sequential oxygen isotope records (δ18Ophosphate vs. VSMOW) of horse tooth enamel phosphate of six individuals from two adjacent Palaeolithic sites in Lower Austria. Three molars from the site Krems‐Wachtberg date to 33–31k cal a bp, and three molars from Kammern‐Grubgraben to 24–20k cal a bp. All teeth show seasonal isotope variations, which are used to reconstruct the annual oxygen isotope composition of drinking water (δ18Odw) and palaeotemperatures. Measured δ18Ophosphate values ranged from 8.6 to 13.0‰ and from 10.8 to 13.9‰ at Krems‐Wachtberg and Kammern‐Grubgraben, respectively. An inverse modelling approach was used to reconstruct summer and winter temperatures after a correction for glacial oceanic source water δ18O. Reconstructed annual δ18Odw was −16.4 ± 1.5‰ at Krems‐Wachtberg and −15.3 ± 1.4‰ at Kammern‐Grubgraben, resulting in annual temperatures of −5.7 ± 3.1 and −3.5 ± 2.9°C, respectively. Summer and winter temperatures reconstructed from individual teeth exhibit high seasonal variations with moderate summer temperatures and extremely low winter temperatures typical for a polar tundra climate. Isotopic differences between individuals are attributed to interannual climate variability or to different drinking water sources. Our reconstructed temperatures are, overall, consistent with previously reported values from European horse teeth, when taking regional differences into account. [ABSTRACT FROM AUTHOR]

Southeastern China's coastal region is considered one of the key areas for studying prehistoric human–land relationships in the Western Pacific region. This region, which is rich in records of marine civilization, provides an ideal location for recording coastal environmental evolution. In this study, the chronological framework of three borehole cores recovered from Haitan Island, South China, near the Keqiutou group of sites, was established using both optically stimulated luminescence (OSL) and accelerator mass spectrometry radiocarbon (AMS 14C) dating techniques. Various analyses, including lithologic characteristics, chroma, clay–water electric conductivity (EC), grain size and elemental geochemistry, were conducted to elaborate the sedimentary sequence and its paleoenvironmental implications. The findings suggest that (i) since the late Quaternary, the Haitan Island sedimentary sequence can be divided into three deposition stages: Old Red Sand formed during Marine Isotope Stage 3 (MIS3), intermittent sedimentation during the Last Glacial Maximum and coastal aeolian deposition during the Holocene. Furthermore, the study reveals that terrestrial debris was significant as a material source for Haitan Island. (ii) Due to the absence of tectonic uplift, Haitan Island has no thick marine sedimentary record during the Holocene period of high sea level. The Luyangpu coastal sand sheet can be dated to 2.78 ka, which is consistent with previous reports giving dates of 2.4 ka. Prior to the formation of the sand sheet, the sedimentary environment in the area was characterized by lagoon or marsh facies. (iii) Paleoanthropological activities were influenced by sedimentary environmental evolution and geomorphic processes, among others. The Keqiutou Culture experienced high sea levels, which created an intertidal environment near the site and facilitated fishing. However, regression at 5.7 ka led to terrestrial environments, which prompted the inhabitants to migrate. Approximately 3 ka ago, sea levels rose again, coinciding with the initiation of rice cultivation. These factors may have influenced the transition from the Neolithic to Bronze Age culture. This study reconstructs evolution of the sedimentary sequence since the late Quaternary, enhancing our understanding of past human–terrestrial relationship in the region. [ABSTRACT FROM AUTHOR]

Glycyrrhiza inflata Batalin is an important medical plant of the genus Glycyrrhiza. It is one of the key protected plants in China, distributed in the desert areas of southern Xinjiang and Dunhuang of Gansu Province. It has a strong resistance to drought, heat, and salt stresses, and plays a pivotal role in sand fixtion in desert areas. In this study, based on 157 valid distribution records and eight environmental factors including climate factors and altitude, the potential distribution area of G. inflata in the last glacial maximum, middle Holocen, modern, and future (2050) times in China were predicted, using the optimized MaxEnt model and ArcGis 10.2 software. The results showed that the predicted distribution area was highly consistent with the current distribution range, and the area under the receiver operating characteristic (AUC) curve was 0.986, indicating that the prediction performance was excellent. The key climatic factors affecting the distribution were precipitation in December and the average annual precipitation. Meanwhile, the suitable area of G. inflata in modern times was 1,831,026 km2, mainly distributed in Turpan-Hami Basin, Tarim Basin, and Dunhuang of Gansu Province, with Lop Nur Town of Xinjiang as the distribution center. In 2050, the potential suitable area forG. inflata in China will be 1,808,090 km2, 250,970 km2 of which will be highly suitable, which is 150,600 km2 smaller than that in modern times, with a reduction rate of 60.0%. Therefore, there is a trend of great reduction in the suitable area of G. inflata. From the last glaciation maximum to the middle Holocene, the geographical distribution center shifted to the southwest margin of the Kumtag Desert, Xinjiang, then later continued to shift to the southwest. This study will provide a basis for understanding the origin and evolution of G. inflata, developing conservation strategies to minimize the impacts of environment change, and utilizing plant resource. [ABSTRACT FROM AUTHOR]

Introduction: Quaternary glaciations, in particular the last glacial maximum (LGM), have shaped the contemporary distribution of many species. In Europe, survival of temperate species during range contractions was mainly associated with refugia in Mediterranean peninsulas, allowing south to north recolonization. Additionally, the Ponto-Caspian refugium provided an east to west migration route. Methods: Here, we investigated genetic diversity and structure of the dispersal-restricted Primula vulgaris Huds., a temperate herb of supposed Caucasian origin, using 12 highly polymorphic nuclear microsatellite loci to trace the colonization of this species in three European regions. We studied 38 populations, namely an eastern mountainous region (Caucasus), a central region (Carpathian Mountains and Dinaric Alps) and a western lowland region (North European Plain). The role of an eastern refugium of the species was tested by performing Approximate Bayesian computation analyses to elucidate its demographic and phylogeographic history, detecting bottleneck and expansion events, and estimating effective (ancestral and current) population sizes and time of divergence. Results and discussion: We found the eastern and central regions featuring the highest allelic richness and genetic differentiation being strong between and within regions. Stepwise-like mutation processes (RST > FST), together with isolation-by-distance patterns, contributed to genetic differentiation. Demographic event models showed that P. vulgaris experienced bottlenecks as well as expansions across its range during the Quaternary glacial cycles, with the last expansion about 6,000, 4,000, and 2,000 generations ago for eastern, central, and western populations, respectively. The best supported origin model pointed to the Caucasus population being closest to an ancestral situation, and from where central and western populations diverged subsequently. Divergence time of the Caucasus populations from an ancestral lineage referred to the Upper Pleistocene (Middle Weichselian). Divergence of Carpathian populations, including a Lower Danube valley corridor, was estimated during and across the LGM (Late Weichselian), confirming central populations as potential secondary cryptic refugium. Western populations recently diverged during the Holocene, most probably in the Atlanticum phase (7,000-3,900 years ago). Within regions, genetic structure was also shaped by latitude, longitude, or altitudinal migration, and for western lowlands, by recent bottleneck and genetic drift processes. [ABSTRACT FROM AUTHOR]

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Stable water isotopes in inland Antarctic ice cores are powerful paleoclimate proxies; however, their relationship with dynamical atmospheric circulations remains controversial. Using a water isotope climate model (MIROC5‐iso), we assessed the influence of the Last Glacial Maximum (LGM; ∼21,000 years ago) sea surface temperatures (SST) and sea ice (SIC) on Antarctic precipitation isotopes (δ18Op) through atmospheric circulation. The results revealed that the synoptic circulation mostly maintained southward moisture transport, reaching inland Antarctica. The steepened meridional SST gradient in the mid‐latitudes increased δ18Op in inland Antarctica with the enhanced baroclinic instability and synoptic moisture transport. In contrast, expanded SIC distribution decreased δ18Op over Antarctica by enhanced preferential removal of heavy isotopes during vapor transport due to the increased transport distance and enhanced surface cooling. These findings propose to use Antarctic ice cores to describe the southern hemisphere atmospheric circulation, represented by the westerly jets, during the LGM and other past climates. Plain Language Summary: Stable water isotopes are widely used to reconstruct past variations of Earth's climate, such as the temperature in Antarctica during the Last Glacial Maximum (LGM) ∼21,000 years ago. This is an essential period for the climate community, given the order of magnitude of the temperature change between the LGM and today, which is similar to that of today's warming. However, the relationship between stable water isotopes and temperature is still subject to debate because of the influence of other climatic factors. Using an isotope‐enabled climate model, we found that the isotopic composition of Antarctic precipitation was not simply associated with the high and low average Antarctic temperature, but was substantially influenced by changes in dynamical atmospheric circulation related to sea surface temperature and sea ice expansion. We also suggest that representation of the past atmospheric circulations, such as westerly jets, can be constrained using water isotopic signals in Antarctic ice cores. Key Points: Synoptic circulations sustained the moisture transport toward inland AntarcticaMeridional sea surface temperature gradient enhanced moisture and heavy isotope precipitations on Antarctica, unlike sea ice expansionAntarctic ice core isotopes may refine southern hemisphere atmospheric circulations during the last glacial maximum [ABSTRACT FROM AUTHOR]

Here, we show that the Last Glacial Maximum (LGM) provides a stronger constraint on equilibrium climate sensitivity (ECS), the global warming from increasing greenhouse gases, after accounting for temperature patterns. Feedbacks governing ECS depend on spatial patterns of surface temperature ("pattern effects"); hence, using the LGM to constrain future warming requires quantifying how temperature patterns produce different feedbacks during LGM cooling versus modern-day warming. Combining data assimilation reconstructions with atmospheric models, we show that the climate is more sensitive to LGM forcing because ice sheets amplify extratropical cooling where feedbacks are destabilizing. Accounting for LGM pattern effects yields a median modern-day ECS of 2.4°C, 66% range 1.7° to 3.5°C (1.4° to 5.0°C, 5 to 95%), from LGM evidence alone. Combining the LGM with other lines of evidence, the best estimate becomes 2.9°C, 66% range 2.4° to 3.5°C (2.1° to 4.1°C, 5 to 95%), substantially narrowing uncertainty compared to recent assessments. [ABSTRACT FROM AUTHOR]

The "Amazon tipping point" is a global change scenario resulting in replacement of upland terra‐firme forests by large‐scale "savannization" of mostly southern and eastern Amazon. Reduced rainfall accompanying the Last Glacial Maximum (LGM) has been proposed to have acted as such a tipping point in the past, with the prediction that terra‐firme inhabiting species should have experienced reductions in population size as drier habitats expanded. Here, we use whole‐genomes of an Amazonian endemic organism (Scale‐backed antbirds – Willisornis spp.) sampled from nine populations across the region to test this historical demography scenario. Populations from southeastern Amazonia and close to the Amazon–Cerrado ecotone exhibited a wide range of demographic patterns, while most of those from northern and western Amazonia experienced uniform expansions between 400 kya and 80–60 kya, with gradual declines toward 20 kya. Southeastern populations of Willisornis were the last to diversify and showed smaller heterozygosity and higher runs of homozygosity values than western and northern populations. These patterns support historical population declines throughout the Amazon that affected more strongly lineages in the southern and eastern areas, where historical "tipping point" conditions existed due to the widespread replacement of humid forest by drier and open vegetation during the LGM. [ABSTRACT FROM AUTHOR]

Lake sediment is an effective archive containing information about past climate change, and accurately determining the deposition age of lake sediment is crucial to investigating past environmental variation. To elucidate the historical climate change modes in the northeastern Qinghai-Tibet Plateau (QTP), the sedimentary profile of a paleolake deposit on the western Qilian Mountains was examined. However, the profile exhibits notable age reversals due to the reservoir effect, as determined by analyzing 46 accelerator mass spectrometry carbon-14 (AMS 14C) dates of bulk organic matter. We therefore conduct a comprehensive examination of carbon-related indicators, including total organic carbon content (TOC), carbon/nitrogen ratio (C/N), and organic carbon isotope (δ13C). And combining with the changing patterns of them in topsoil samples around the northeastern QTP, this study determines that the formation age of the lacustrine sedimentary profile is 16278∼20662 cal a BP, corresponding to the Last Glacial Maximum (LGM) and the last deglaciation. The results of sedimentary facies identified by grain size and carbonate oxygen isotope (δ18O) suggest that this profile was developed near the paleolake shoreline, resulting from a transition in lake environment from deep to shallow during the LGM and the last deglaciation. The corresponding reconstructed lake area and precipitation are 642 km2 and 238 mm, respectively, indicating a wet and cold climate mode in the northeastern QTP during this time. Furthermore, the wetter state in the northeastern QTP can be attributed to a combination of reduced evaporation caused by colder conditions and enhanced precipitation driven by stronger southerly westerly jet streams. [ABSTRACT FROM AUTHOR]

Species assemblage composition of marine microfossils offers the possibility to investigate ecological and climatological change on time scales inaccessible using conventional observations. Planktonic foraminifera - calcareous zooplankton - have an excellent fossil record and are used extensively in palaeoecology and palaeoceanography. During the Last Glacial Maximum (LGM; 19,000 – 23,000 years ago), the climate was in a radically different state. This period is therefore a key target to investigate climate and biodiversity under different conditions than today. Studying LGM climate and ecosystems indeed has a long history, yet the most recent global synthesis of planktonic foraminifera assemblage composition is now nearly two decades old. Here we present the ForCenS-LGM dataset with 2,365 species assemblage samples collected using standardised methods and with harmonised taxonomy. The data originate from marine sediments from 664 sites and present a more than 50% increase in coverage compared to previous work. The taxonomy is compatible with the most recent global core top dataset, enabling direct investigation of temporal changes in foraminifera biogeography and facilitating seawater temperature reconstructions. [ABSTRACT FROM AUTHOR]

Global hydroclimate significantly differed from modern climate during the mid-Holocene (6 ka) and Last Glacial Maximum (21 ka). Consequently, both periods have been described as either a partial or reverse analogue for current climate change. To reconstruct past hydroclimate, an offline paleoclimate data assimilation methodology is applied to a dataset of 130 lake status records which provide relative estimates of water level measured using percentile units. The proxy observations are integrated with the climate dynamics of two transient simulations (TraCE-21ka and HadCM3) using a multivariate proxy system model (PSM) which estimates relative lake status from available climate simulation variables. The resulting DAMP-21ka (Data Assimilation of Moisture Patterns 21,000–0 BP) reanalysis reconstructs annual lake status and precipitation values at 500-year resolution and represents the first application of the methodology to global hydroclimate on timescales spanning the Holocene and longer. Validation using Pearson's correlation coefficients indicates that the reconstruction (0.33) is more skillful, on average, than model simulations (0.10), particularly in portions of North America and East Africa where data density is high and proxy-model disagreement is prominent during the Holocene. Results of the PSM and assimilation are used to evaluate climatic controls on lake status, spatiotemporal patterns of moisture variability, and proxy-model disagreement. During the mid-Holocene, wetter conditions are reconstructed for North and East Africa, Asia, and southern Australia, but, in contrast to the model prior, negative anomalies are observed in North America resulting in drier than modern conditions throughout the Northern Hemisphere midlatitudes. Proxy-model disagreement in western North America may reflect a bias in model simulations to stronger sea level pressure gradients in the North Pacific during the mid-Holocene. The data assimilation framework is able to reconcile these differences by integrating the constraints of proxy observations with the dynamics of the model prior to produce a more robust estimation of hydroclimate variability during the past 21,000 years. [ABSTRACT FROM AUTHOR]

The function of tropical peatland as a carbon sink is a balance between peat accumulation and peat loss; however, various interacting factors are involved affecting this process. In this study, we collected and intensively radiocarbon dated peat cores from two peat domes, visualized their cross-sectional profiles of geochemical properties, and developed three macrocharcoal records from each peat dome. We find that the young (4500 y calBP) and shallow (6 m) coastal peat has a simple and linear age–depth relationship, showing stable accumulation of carbon during the late Holocene. In contrast, the older (ca. 40,000 y cal BP) and deeper (15 m) inland peat shows a more complex history, where we observed age reversals and hiatuses, likely caused by climate variability from the Last Glacial Maximum (LGM) to the Holocene. The charcoal record reveals a continuous presence of low-severity fire as indicated by charcoal morphotypes, though fire frequency increased after agriculture was established. An age reversal during the LGM was likely caused by a flood. Two periods of hiatuses occurred, each several millennia in length, at the end of the LGM and during the early Holocene. One cause of the hiatuses may have been a climatically halted peat formation from low precipitation and cooler climate during the LGM. Another cause may have been that severe fires consumed thousands of years of accumulated peat. If the hiatuses were entirely due to fire, the carbon released from these paleo-fire events (600 t C ha−1) suggests several times the impact of the most intense modern peat fires. [ABSTRACT FROM AUTHOR]

Aim: Patterns of individual variation are key to testing hypotheses about the mechanisms underlying biogeographic patterns. If species distributions are determined by environmental constraints, then populations near range margins may have reduced performance and be adapted to harsher environments. Model organisms are potentially important systems for biogeographical studies, given the available range‐wide natural history collections, and the importance of providing biogeographical context to their genetic and phenotypic diversity. Location: Global. Taxon: Arabidopsis thaliana ('Arabidopsis'). Methods: We fit occurrence records to climate data, and then projected the distribution of Arabidopsis under last glacial maximum, current and future climates. We confronted model predictions with individual performance measured on 2194 herbarium specimens, and we asked whether predicted suitability was associated with life history and genomic variation measured on ~900 natural accessions. Results: The most important climate variables constraining the Arabidopsis distribution were winter cold in northern and high elevation regions and summer heat in southern regions. Herbarium specimens from regions with lower habitat suitability in both northern and southern regions were smaller, supporting the hypothesis that the distribution of Arabidopsis is constrained by climate‐associated factors. Climate anomalies partly explained interannual variation in herbarium specimen size, but these did not closely correspond to local limiting factors identified in the distribution model. Late‐flowering genotypes were absent from the lowest suitability regions, suggesting slower life histories are only viable closer to the centre of the realized niche. We identified glacial refugia farther north than previously recognized, as well as refugia concordant with previous population genetic findings. Lower latitude populations, known to be genetically distinct, are most threatened by future climate change. The recently colonized range of Arabidopsis was well‐predicted by our native‐range model applied to certain regions but not others, suggesting it has colonized novel climates. Main Conclusions: Integration of distribution models with performance data from vast natural history collections is a route forward for testing biogeographical hypotheses about species distributions and their relationship with evolutionary fitness across large scales. [ABSTRACT FROM AUTHOR]

Previous archaeological evidence and published analysis has suggested that ochre was first used in the Sydney Basin around 9000 years ago, and that the Parramatta region may not have been occupied by First Nations peoples before ∼14 ka. We present new evidence which firmly places both events before the Last Glacial Maximum (LGM). Multiple ochre fragments, two with microscopically visible evidence of anthropogenic grinding, were recovered from the George Street Gatehouse site within the Parramatta Sand Body (PSB) at Parramatta. The ground ochre was associated with a pit feature buried within the PSB and dated by optically stimulated luminescence (OSL) between ∼35 and 30 ka. This find is the earliest evidence for ochre processing in the Sydney Basin by some 25000 years. A previous model for the region had proposed that occupation prior to and during the LGM was focussed on the Hawkesbury‐Nepean River corridor as a refugium, with only equivocal evidence of occupation prior to ∼14 ka at Parramatta (Williams et al., 2021). We propose that the Parramatta River could also have acted as a refugium for people moving through and occupying the now‐drowned Pleistocene coastal zone; and that those people used ochre in their symbolic expressions. [ABSTRACT FROM AUTHOR]

Authigenic Mg‐calcite and dolomite are frequently observed in restricted, evaporative environments, such as lagoon or lake systems, but their formation is difficult to capture due to slow growth rates. Lake Neusiedl, an alkaline and subhaline lake with a mean water depth of 0.7 m in Austria, offers a natural system to study the precipitation of Ca‐Mg‐carbonate phases, which occur as fine‐grained, unconsolidated and largely homogenized mud. To elucidate the timing and formation mechanisms of these authigenic carbonate phases, the mineralogical and isotopic composition and radiocarbon age of different sediment grain‐size fractions from <0.2 to >3.0 μm were analysed. X‐ray diffraction analyses show two broad peaks of Mg‐calcite and protodolomite (lacking ordering peaks), suggesting that the carbonates are authigenic rather than detrital in origin. Calibrated carbon‐14 ages range between 200 cal yr bp and 3700 cal yr bp. The linear correlation of age and grain size suggests a very slow growth rate of single crystals of 0.23 to 0.60 μm/ka. These rates suggest an extremely slow sedimentation rate in a shallow lake that existed during most of the Holocene. The higher abundance of protodolomite in older grain fractions, in contrast to the presence of high‐Mg calcite in the youngest fractions, suggests a growth succession where high‐Mg calcite develops first and subsequently transforms into protodolomite. Much higher ages of 6 cal ka bp to 15 cal ka bp are measured in carbonates of lake deposits exposed on land, in a section north‐west of the recent lake, suggesting a growth rate of those carbonate minerals of 0.13 μm/ka. These time constraints further suggest that some carbonate grains could already have nucleated from lake water before or during the last glacial maximum, although under slightly different hydrochemical conditions. [ABSTRACT FROM AUTHOR]

Phylogeographic studies of continental clades, especially when combined with palaeoclimate modelling, provide powerful insight into how environment drives speciation across climatic contexts. Australia, a continent characterized by disparate modern biomes and dynamic climate change, provides diverse opportunity to reconstruct the impact of past and present environments on diversification. Here, we use genomic‐scale data (1310 exons and whole mitogenomes from 111 samples) to investigate Pleistocene diversification, cryptic diversity, and secondary contact in the Australian delicate mice (Hydromyini: Pseudomys), a recent radiation spanning almost all Australian environments. Across northern Australia, we find no evidence for introgression between cryptic lineages within Pseudomys delicatulus sensu lato, with palaeoclimate models supporting contraction and expansion of suitable habitat since the last glacial maximum. Despite multiple contact zones, we also find little evidence of introgression at a continental scale, with the exception of a potential hybrid zone in the mesic biome. In the arid zone, combined insights from genetic data and palaeomodels support a recent expansion in the arid specialist P. hermannsburgensis and contraction in the semi‐arid P. bolami. In the face of repeated secondary contact, differences in sperm morphology and chromosomal rearrangements are potential mechanisms that maintain species boundaries in these recently diverged species. Additionally, we describe the western delicate mouse as a new species and recommend taxonomic reinstatement of the eastern delicate mouse. Overall, we show that speciation in an evolutionarily young and widespread clade has been driven by environmental change, and potentially maintained by divergence in reproductive morphology and chromosome rearrangements. [ABSTRACT FROM AUTHOR]

The shift in climate that occurred between the Last Glacial Maximum (LGM) and the Early Holocene (ca. 18–12 kyr BP) displayed rates of temperature increase similar to present-day warming trends. The most rapid recorded changes in temperature occurred during the abrupt climate oscillations known as the Bølling–Allerød interstadial (14.7–12.9 kyr BP) and the Younger Dryas stadial (12.9–11.7 kyr BP). Reconstructing ice sheet dynamics during these climate oscillations provides the opportunity to assess long-term ice sheet evolution in reaction to a rapidly changing climate. Here, we use glacial geomorphological inversion methods (flowsets) to reconstruct the ice flow dynamics and the marginal retreat pattern of the southwestern sector of the Laurentide Ice Sheet (SWLIS). We combine our reconstruction with a recently compiled regional deglaciation chronology to depict ice flow dynamics that encompass the time period from pre-LGM to the Early Holocene. Our reconstruction portrays three macroscale reorganizations in the orientation and dynamics of ice streaming followed by regional deglaciation associated with rapid warming during the Bølling–Allerød interstadial. Initial westward flow is documented, likely associated with an early set of ice streams that formed during the advance to the LGM. During the LGM ice streaming displays a dominant north to south orientation. Ice sheet thinning at ∼15 ka is associated with a macroscale reorganization in ice stream flow, with a complex of ice streams recording south-eastward flow. A second macroscale reorganization in ice flow is then observed at ∼14 ka, in which southwestern ice flow is restricted to the Hay, Peace, Athabasca, and Churchill river lowlands. Rates of ice sheet retreat then slowed considerably during the Younger Dryas stadial; at this time, the ice margin was situated north of the Canadian Shield boundary and ice flow continued to be sourced from the northeast. Resulting from these changes in ice sheet dynamics, we recognize a three-part pattern of deglacial landform zonation within the SWLIS characterized by active ice margin recession, stagnation and downwasting punctuated by local surging (terrestrial ice sheet collapse): the outer deglacial zone contains large recessional moraines aligned with the direction of active ice margin retreat; the intermediate deglacial zone contains large regions of hummocky and stagnation terrain, in some areas crosscut by the signature of local surges, reflecting punctuated stagnation and downwasting; and the inner deglacial zone contains inset recessional moraines demarcating progressive regional ice margin retreat. We attribute these macroscale changes in ice flow geometry and associated deglacial behaviour to external climatic controls during the Bølling–Allerød and Younger Dryas but also recognize the role of internal (glaciological, lithological and topographic) controls in SWLIS dynamics. [ABSTRACT FROM AUTHOR]

South India's Western Ghats are a global biodiversity hotspot and an area of conservation concern with numerous endemic species. There is an urgent need for accurate threat assessments for these species, including the Nilgiri Pipit (Anthus nilghiriensis). The Nilgiri pipit is endemic to the montane grasslands of the Western Ghats, and has experienced recent rapid habitat declines. Here, we characterize the climatic niche of this species using environmental niche modelling, and use these models to estimate its range and threat status. Using the Maxent modelling algorithm and presence data from surveys by expert observers, we find that the Nilgiri Pipit is strongly sensitive to higher temperatures. We project the best-performing models to the last glacial maximum and find evidence that the species had a considerably larger range under that climatic regime. We estimate that the extent of suitable available habitat is no more than 436 km2 even using the most conservative threshold. Based on this result, and the documented decline in and fragmentation of its habitat, we recommend that the species be uplisted to "endangered" on the IUCN Red List, from its current status of "vulnerable". Finally, we compare these results to models based on identically processed eBird data, and find that eBird data produce larger estimates of suitable habitat: we, therefore, recommend caution in the interpretation of environmental niche models based on eBird data. [ABSTRACT FROM AUTHOR]

The INMIO-CICE hydrodynamic model of the Caspian Sea was used to calculate equilibrium river runoff and evaporation from the sea surface over a wide range of sea levels (from –85 to +50 m a.s.l.) for different climatic conditions: the Last Glacial Maximum (about 21 ka BP) and the pre-industrial climate (~1850). Data from the INMCM4.8 climate model were used as boundary conditions. It was found out that a river runoff of about 400 km3/yr was required in the Last Glacial Maximum to maintain the sea level at 35–50 m a.s.l. corresponding to the maximum values of the Khvalynian transgression. In the Last Glacial Maximum, evaporation from the sea surface decreased by 105–175 mm (12–22%), and a precipitation layer, according to the INMCM4.8 model, decreased by 50–70 mm (15–30%). These conditions caused the equilibrium runoff to decrease by about 10–20% compared to the pre-industrial conditions. Smaller absolute and relative changes corresponded to lower sea levels. The maximum evaporation decrease occurred at 5 m a.s.l. [ABSTRACT FROM AUTHOR]

The largest continuous patch of Seasonally Dry Tropical Forests (SDTF) is the Caatinga Biome in north-eastern Brazil, which has the greatest biodiversity and highest degree of endemism compared to any other SDTF patch of South America. Our aim was to conduct a phylogeographic study with Euphorbia phosphorea to understand the evolutionary history of this species endemic to the Caatinga Biome. We studied genetic diversity and structure, demographic dynamics, as well as intraspecific phylogenetic relationships, based on plastidial and nuclear DNA. In addition, we conducted species distribution modelling (SDM) to infer connectivity since the Last Interglacial. Our results recovered a stronger genetic structure for plastidial than for nuclear genome, which probably result from distinct species capability to seed and pollen dispersal, and low levels of genetic diversity within populations. Although SDM results suggest higher connectivity during Last Maximum Glacial, demographic analyses detected no signs of demographic expansion in this period. In agreement with previous studies with rock specialists, our data reveal remarkable among-population differentiation and low within-population genetic diversity, which make populations more prone to drift effects. Furthermore, our results shed light on the importance of early Pleistocene events in the diversification of lineages within the Caatinga Biome, although further comparative work is required. [ABSTRACT FROM AUTHOR]

Simple Summary: The Mongolian racerunner (Eremias argus) is a genetically diverse species with a wide distribution across Northeast Asia. The present study is the first to assess the genetic variation in E. argus across its entire geographic range using newly generated mtDNA cyt b and previously published data. We show the complex genetic pattern of this species, where most genetic divergence is not associated with geographic regions. This pattern is the result of multiple influences–robust dispersal ability resulting from ecological features, anthropogenic influence of translocation, and past climate change. Geographic distance has primarily shaped the genetic structure of the species, as indicated by a strong pattern of isolation by distance across all populations. The population growth of E. argus from the Last Interglacial to the Last Glacial Maximum is likely a consequence of an increase in favorable habitats with mild climates following the development of monsoons in East Asia since the mid-Late Pleistocene. Overall, the population genetic structure of E. argus was likely driven by a combination of climatic and geographic changes rather than direct ice sheet coverage. Our results highlight the importance of combining genetic approaches with environmental data when assessing the impact of Pleistocene climatic oscillations. The Mongolian racerunner, Eremias argus, is a small lizard endemic to Northeast Asia that can serve as an excellent model for investigating how geography and past climate change have jointly influenced the evolution of biodiversity in this region. To elucidate the processes underlying its diversification and demography, we reconstructed the range-wide phylogeographic pattern and evolutionary trajectory, using phylogenetic, population genetic, landscape genetic, Bayesian phylogeographic reconstruction and ecological niche modeling approaches. Phylogenetic analyses of the mtDNA cyt b gene revealed eight lineages that were unbounded by geographic region. The genetic structure of E. argus was mainly determined by geographic distance. Divergence dating indicated that E. argus and E. brenchleyi diverged during the Mid-Pliocene Warm Period. E. argus was estimated to have coalesced at~0.4351 Ma (Marine Isotope Stage 19). Bayesian phylogeographic diffusion analysis revealed out-of-Inner Mongolia and rapid colonization events from the end of the Last Interglacial to the Last Glacial Maximum, which is consistent with the expanded suitable range of the Last Glacial Maximum. Pre-Last Glacial Maximum growth of population is presented for most lineages of E. argus. The Glacial Maximum contraction model and the previous multiple glacial refugia hypotheses are rejected. This may be due to an increase in the amount of climatically favorable habitats in Northeast Asia. Furthermore, E. argus barbouri most likely represents an invalid taxon. The present study is the first to report a range-wide phylogeography of reptiles over such a large region in Northeast Asia. Our results make a significant contribution towards understanding the biogeography of the entire Northeast Asia. [ABSTRACT FROM AUTHOR]

Aim: To assess the relative relevance of dispersal limitation and species sorting as drivers of spatial turnover between spider faunas of European territories. Location: Continental Europe. Time period: Present. Major taxa studied: Spiders (Order Araneae). Methods: We analysed how distance‐decay patterns differ between northern and southern Europe (broadly, territories covered vs. not covered by ice sheets during the last glacial maximum, respectively) in 15 spider families, using standardized distances to allow a direct comparison between parameters (i.e. slope and intercept) of climatic and spatial distance‐decay models. Thus, we assessed North–South differences in parameters of spatial and, independently, climatic distance‐decay models, and whether those differences are explained by family‐specific traits related to dispersal ability. Results: Climatic and spatial distance‐decay patterns are very similar in northern Europe, where climatic and spatial distances are highly correlated. In contrast, slopes are steeper in spatial than in climatic distance‐decay curves in southern Europe, where climatic and spatial distances are decoupled. Moreover, family traits related to dispersal ability explained the North–South difference in spatial distance‐decay slopes, as well as the amount of nestedness‐resultant dissimilarity between southern and northern spider faunas. Main conclusions: Our results suggest that differences in beta diversity patterns between northern and southern Europe reflect the strength of dispersal limitation in spiders, which varies across families and leads to different degrees of disequilibrium with current climatic conditions depending on the taxon. Moreover, in the South of Europe, where spatial and climatic distances are uncorrelated, spatial distance‐decay models are steeper and have larger explanatory power than climatic distance‐decay models, which suggests that dispersal limitation is the main factor shaping current beta diversity patterns of European spiders at the continental scale. [ABSTRACT FROM AUTHOR]

An asthenospheric window underneath much of the South American continent increases the heat flow in the southern Patagonian Andes where glacial–interglacial cycles drive the building and melting of the Patagonian Icefields since the latest Miocene. The Last Glacial Maximum (LGM) was reached ∼26000 yr BP (years before present). Significant deglaciation onsets between 21 000 and 17 000 yr BP were subject to an acceleration since the Little Ice Age (LIA), which was ∼400 yr BP. Fast uplift rates of up to 41±3 mm yr -1 are measured by global navigation satellite system (GNSS) around the Southern Patagonian Icefield and are currently ascribed to post-LIA lithospheric rebound, but the possible longer-term post-LGM rebound is poorly constrained. These uplift rates, in addition, are 1 order of magnitude higher than those measured on other glaciated orogens (e.g. the European Alps), which raises questions about the role of the asthenospheric window in affecting the vertical surface displacement rates. Here, we perform geodynamic thermo-mechanical numerical modelling to estimate the surface uplift rates induced by post-LIA and post-LGM deglaciation, accounting for temperature-dependent rheologies and different thermal regimes in the asthenosphere. Our modelled maximum post-glacial rebound matches the observed uplift rate budget only when both post-LIA and post-LGM deglaciation are accounted for and only if a standard continental asthenospheric mantle potential temperature is increased by 150–200 °C. The asthenospheric window thus plays a key role in controlling the magnitude of presently observed uplift rates in the southern Patagonian Andes. [ABSTRACT FROM AUTHOR]

Recent studies have suggested that dogs were domesticated during the Last Glacial Maximum (LGM) in Siberia, which contrasts with previous proposed domestication centers (e.g. Europe, the Middle East, and East Asia). Ancient DNA provides a powerful resource for the study of mammalian evolution and has been widely used to understand the genetic history of domestic animals. To understand the maternal genetic history of East Asian dogs, we have made a complete mitogenome dataset of 120 East Asian canids from 38 archaeological sites, including 102 newly sequenced from 12.9 to 1 ka BP (1,000 years before present). The majority (112/119, 94.12%) belonged to haplogroup A, and half of these (55/112, 49.11%) belonged to sub-haplogroup A1b. Most existing mitochondrial haplogroups were present in ancient East Asian dogs. However, mitochondrial lineages in ancient northern dogs (northeastern Eurasia and northern East Asia) were deeper and older than those in southern East Asian dogs. Results suggests that East Asian dogs originated from northeastern Eurasian populations after the LGM, dispersing in two possible directions after domestication. Western Eurasian (Europe and the Middle East) dog maternal ancestries genetically influenced East Asian dogs from approximately 4 ka BP, dramatically increasing after 3 ka BP, and afterwards largely replaced most primary maternal lineages in northern East Asia. Additionally, at least three major mitogenome sub-haplogroups of haplogroup A (A1a, A1b, and A3) reveal at least two major dispersal waves onto the Qinghai-Tibet Plateau in ancient times, indicating eastern (A1b and A3) and western (A1a) Eurasian origins. [ABSTRACT FROM AUTHOR]

Conserving pollinators has been a concern and priority for ecological programs around the world, since these animals play a major role in forest ecosystems. Bees are among the main pollinators of these ecosystems. Here we used paleomodeling to infer refuge areas that putatively concentrate high levels of genetic diversity for stingless bees and that would be priorities for conservation of these pollinators within Caatinga, a seasonally dry forest in Neotropical Dry Diagonal. In this sense, a total of 319 records of 10 species was used to build species models for the current days, Mid-Holocene and Last Glacial Maximum periods using MaxEnt algorithm. The results indicated climatically-stable areas (i.e., refuges) for each stingless bee species, where higher levels of historical genetic diversity are expected in the Caatinga. Moreover, a large continuous range of suitable areas for the assemblage in the Caatinga, divided into four main refuges, which likely concentrate high levels of genetic diversity for these pollinators, were observed. Considering that the Caatinga is threatened and has experienced an increase of deforestation in recent years, this inference of refuge areas should be useful to direct the choice of new conservation units. Our results also provide spatial insights for future phylogeographic studies involving these insects, which are recommended and might reinforce these findings. Conservation policies directed at preserving pollinating species may be an effective mechanism for preserving the biodiversity in the threatened Caatinga. Implications for insect conservation: Our study inferred four main refuge areas within this region that putatively concentrate high diversity for stingless bees, which should be considered as a priority in conservation strategies in the threatened Caatinga. In addition, we suggest evaluating the creation of new Conservation Units considering refuges areas proposed to the assembly of pollinators from this Neotropical dry forest, since this region exhibits high levels of species richness and endemism. [ABSTRACT FROM AUTHOR]

An increasing number of climate model simulations is becoming available for the transition from the Last Glacial Maximum to the Holocene. Assessing the simulations' reliability requires benchmarking against environmental proxy records. To date, no established method exists to compare these two data sources in space and time over a period with changing background conditions. Here, we develop a new algorithm to rank simulations according to their deviation from reconstructed magnitudes and temporal patterns of orbital and millennial-scale temperature variations. The use of proxy forward modeling allows for accounting for non-climatic processes that affect the temperature reconstructions. It further avoids the need to reconstruct gridded fields or regional mean temperature time series from sparse and uncertain proxy data. First, we test the reliability and robustness of our algorithm in idealized experiments with prescribed deglacial temperature histories. We quantify the influence of limited temporal resolution, chronological uncertainties, and non-climatic processes by constructing noisy pseudo-proxies. While model–data comparison results become less reliable with increasing uncertainties, we find that the algorithm discriminates well between simulations under realistic non-climatic noise levels. To obtain reliable and robust rankings, we advise spatial averaging of the results for individual proxy records. Second, we demonstrate our method by quantifying the deviations between an ensemble of transient deglacial simulations and a global compilation of sea surface temperature reconstructions. The ranking of the simulations differs substantially between the considered regions and timescales, which suggests that optimizing for agreement with the temporal patterns of a small set of proxies might be insufficient for capturing the spatial structure of the deglacial temperature variability. We attribute the diversity in the rankings to more regionally confined temperature variations in reconstructions than in simulations, which could be the result of uncertainties in boundary conditions, shortcomings in models, or regionally varying characteristics of reconstructions such as recording seasons and depths. Future work towards disentangling these potential reasons can leverage the flexible design of our algorithm and its demonstrated ability to identify varying levels of model–data agreement. Additionally, the algorithm can be applied to variables like oxygen isotopes and climate transitions such as the penultimate deglaciation and the last glacial inception. [ABSTRACT FROM AUTHOR]

The last deglaciation (∼20 –11 ka BP) is a period of a major, long-term climate transition from a glacial to interglacial state that features multiple centennial- to decadal-scale abrupt climate variations whose root cause is still not fully understood. To better understand this time period, the Paleoclimate Modelling Intercomparison Project (PMIP) has provided a framework for an internationally coordinated endeavour in simulating the last deglaciation whilst encompassing a broad range of models. Here, we present a multi-model intercomparison of 17 transient simulations of the early part of the last deglaciation (∼20 –15 ka BP) from nine different climate models spanning a range of model complexities and uncertain boundary conditions and forcings. The numerous simulations available provide the opportunity to better understand the chain of events and mechanisms of climate changes between 20 and 15 ka BP and our collective ability to simulate them. We conclude that the amount of freshwater forcing and whether it follows the ice sheet reconstruction or induces an inferred Atlantic meridional overturning circulation (AMOC) history, heavily impacts the deglacial climate evolution for each simulation rather than differences in the model physics. The course of the deglaciation is consistent between simulations except when the freshwater forcing is above 0.1 Sv – at least 70 % of the simulations agree that there is warming by 15 ka BP in most places excluding the location of meltwater input. For simulations with freshwater forcings that exceed 0.1 Sv from 18 ka BP, warming is delayed in the North Atlantic and surface air temperature correlations with AMOC strength are much higher. However, we find that the state of the AMOC coming out of the Last Glacial Maximum (LGM) also plays a key role in the AMOC sensitivity to model forcings. In addition, we show that the response of each model to the chosen meltwater scenario depends largely on the sensitivity of the model to the freshwater forcing and other aspects of the experimental design (e.g. CO2 forcing or ice sheet reconstruction). The results provide insight into the ability of our models to simulate the first part of the deglaciation and how choices between uncertain boundary conditions and forcings, with a focus on freshwater fluxes, can impact model outputs. We can use these findings as helpful insight in the design of future simulations of this time period. [ABSTRACT FROM AUTHOR]

The Last Glacial Maximum (LGM; 26,000–19,000 years before the present) altered the distribution of species worldwide. Its effect is poorly known in tropical regions because the cooling and drought reached during that period are uncertain. Here, I generated hypotheses regarding the possible responses of cloud forest mammals in the Oaxacan Highlands (OH) of Mexico, a region with one of the most extensive cloud forests in the Neotropics. First, I used three General Circulation Models (GCMs: CCSM3, MIROC‐ESM and MPI) to characterize probable climates during the LGM. Then, I used ecological niche models to estimate the current and LGM potential distributions of four cloud forest species. As in other locations, the results show that GCMs are consistent with cooler conditions relative to today; however, the three GCMs estimate precipitation regimes with notable variations in the region. MPI indicates that the LGM could have been even wetter than present. Consequently, the MPI scenario allowed more widespread potential distributions of mammals. The paleodistributions show how mid‐ and lowlands were essential for the long‐term survival of these 'high‐mountain mammals' throughout the last glacial–interglacial cycle. The paleodistributions presented here are precise hypotheses that can be tested based on paleoecological and genetic evidence. [ABSTRACT FROM AUTHOR]

There are few studies on the climate and glacial scale in the mountains east of the Qinghai–Tibet Plateau. So, we used glacial features to determine the range of the area's paleoglaciers and the equilibrium line altitude (ELA) of theGlA modern and paleoglaciers in the Tianchi area of the Changbai Mountains. Then, the GlaRe toolbox 2015 () was used to reconstruct the surface of the paleoglaciers. The probable air temperature during the glacial advances of the LGM was calculated by applying the P-T and LR models. The results showed the following: (1) the change in ELA is 950 m in the Tianchi area of the Changbai Mountains; (2) glacial coverage in the Tianchi area of the Changbai Mountains during the LGM period was ~27.05 km2 and the glacial volume was ~9.94 km3; and (3) the mean temperature in the Tianchi area of the Changbai Mountains during the LGM was 6.6–9.0 °C lower than today's, and was the principal factor controlling the growth of glaciers. There is a difference in the climate change in monsoon-influenced mountains during the LGM, and this difference may be related to the precipitation in the mountains. [ABSTRACT FROM AUTHOR]

We conducted two‐dimensional numerical simulations to investigate the mechanisms underlying the strong spatiotemporal correlation observed between submarine landslides and gas hydrate dissociation due to glacial sea‐level drops. Our results suggest that potential plastic deformation or slip could occur at localized and small scales in the shallow‐water portion of the gas hydrate stability zone (GHSZ). This shallow‐water portion of the GHSZ typically lies within the area enclosed by three points: the BGHSZ–seafloor intersection, the seafloor at ∼600 m below sea level (mbsl), and the base of the GHSZ (BGHSZ) at ∼1,050 mbsl in low‐latitude regions. The deep BGHSZ (>1,050 mbsl) could not slip; therefore, the entire BGHSZ was not a complete slip surface. Glacial hydrate dissociation alone is unlikely to cause large‐scale submarine landslides. Observed deep‐water (much greater than 600 mbsl) turbidites containing geochemical evidence of glacial hydrate dissociation potentially formed from erosion or detachment in the GHSZ pinch‐out zone. Plain Language Summary: Many submarine landslides spatiotemporally correlate with gas hydrate dissociation. However, direct mechanical evidence supporting whether the overpressure and deformation due to glacial sea‐level drop‐induced hydrate dissociation are adequate for triggering submarine landslides is lacking. Here, we present two‐dimensional thermal‐hydraulic‐chemical and geomechanical models of a gas‐hydrate system in response to glacial sea‐level drops and conduct sensitivity analyses of the model behavior under a wide range of key conditions from a global perspective. Our simulations suggest that glacial hydrate dissociation might induce plastic deformation or slip at localized and small scales only possibly within the shallow‐water portion of the hydrate stability zone. The deep part (>1,050 m below sea level) of the bottom boundary of the hydrate stability zone could not slip; therefore, the entire bottom boundary of the hydrate stability zone was not a complete slip surface. We demonstrate that glacial hydrate dissociation alone is unlikely to trigger large‐scale submarine landslides. Our work highlights the vicinity of the upper limit of the hydrate stability zone (where the base of the hydrate stability zone intersects the seafloor) as an important area for investigating overpressure and focused fluid flow, localized plastic deformation or slip, and downslope sediment transport related to glacial hydrate dissociation. Key Points: Glacial hydrate dissociation might cause potential plastic deformation or slip at localized and small scales in shallow parts of the GHSZThe large deformation surface at the BGHSZ boundary of the potential plastic deformation zone was not a complete slip surfaceGlacial sea‐level drop‐induced gas hydrate dissociation alone is unlikely to have caused large‐scale submarine landslides [ABSTRACT FROM AUTHOR]

The correlation between the amount of organic carbon (OC) and sulfur (S) in sediments has been widely used as a paleosalinity indicator to distinguish between marine and freshwater environments. However, whether the ratio of total OC to total S (TOC/TS) can be used to identify unsteady or dynamic marine environments across sedimentary strata is still contended. An HZW1907 sediment core of 80 m in length was successfully collected in the middle of Hangzhou Bay (HZB), serving as one of the few boreholes that are crucial for the study of geologic and geo-environment changes in the coastal regions of eastern China since the Last Glacial Maximum (LGM). Total OC (TOC), stable carbon isotope, and TS of 82 subsamples from the HZW1907 core were analyzed to reconstruct the history of the shallow water biological pump and sulfur preservation record in the bay since the Late Pleistocene. Our results indicate that the samples had low concentrations of TOC (0.21%) and total nitrogen (TN) (0.02%), high mass ratio of TOC/TN (10.8), low δ13C (-24.9%0), low TS content (0.06%), and a high ratio of TOC/TS (9.1) from 33.6 ka BP to 12.3 ka BP, implying that freshwater organic matter (OM), algae, and C3 plant fragments were the main sources of OM in a relatively cold environment. The abundances of TOC, TN, and TS increased to 0.56%, 0.07%, and 0.4%, respectively, while δ13C (-23.9%) increased and TOC/TS (2.7) decreased in the Holocene sediments, suggesting that seawater began to influence the composition of the sediments of HZB. Climate warming, which is likely to have impacted the results, was experienced from 12.3 ka BP. An OC isotope mixing model indicated that since the Mid-late Holocene, more than 70% of riverine OM accounted for the total OM. The TOC/TS ratio was identified as an effective indicator of seawater intrusion, with C/S ratios of 1-6 being considered to indicate a "sea-land transitional zone" sedimentary environment, a C/S >6 indicating freshwater, and a C/S<1 indicating normal marine facies. These findings provide crucial evidence for using TOC/TS to distinguish freshwater from marine environments and enhance our understanding of past climate changes. Therefore, these geochemical indicators can be used in conjunction with other sedimentary records to obtain accurate results about sedimentary evolution. [ABSTRACT FROM AUTHOR]

Introduction: The Koraga tribe are an isolated endogamous tribal group found in the southwest coastal region of India. The Koraga language shares inherited grammatical features with North Dravidian languages. To seek a possible genetic basis for this exceptionality and understand the maternal lineage pattern, we have aimed to reconstruct the inter-population and intra-population relationships of the Koraga tribal population by using mtDNA markers for the hypervariable regions along with a partial coding region sequence analysis. Methods and Results: Amongst the 96 individuals studied, we observe 11 haplogroups, of which a few are shared and others are unique to the clans Soppu, On _ t_ i and Kun _ t_ u. In addition to several deep rooted Indian-specific lineages of macrohaplogroups M and U, we observe a high frequency of the U1 lineage (~38%), unique to the Koraga. A Bayesian analysis of the U1 clade shows that the Koraga tribe share their maternal lineage with ancestral populations of the Caucasus at the cusp of the Last Glacial Maximum. Discussion: Our study suggests that the U1 lineage found in the Indian subcontinent represents a remnant of a post-glacial dispersal. The presence of West Asian U1 when viewed along with historical linguistics leads us to hypothesise that Koraga represents a mother tongue retained by a vanquished population group that fled southward at the demise of the Indus civilisation as opposed to a father tongue, associated with a particular paternal lineage. [ABSTRACT FROM AUTHOR]

The Qinling Mountains in East Asia serve as the geographical boundary between the north and south of China and are also indicative of climatic differences, resulting in rich ecological and species diversity. However, few studies have focused on the responses of plants to geological and climatic changes in the Qinling Mountains and adjacent regions. Therefore, we investigated the evolutionary origins and phylogenetic relationships of three Pedicularis species in there to provide molecular evidence for the origin and evolution of plant species. Ecological niche modeling was used to predict the geographic distributions of three Pedicularis species during the last interglacial period, the last glacial maximum period, and current and future periods, respectively. Furthermore, the distribution patterns of climate fluctuations and the niche dynamics framework were used to assess the equivalence or difference of niches among three Pedicularis species. The results revealed that the divergence of three Pedicularis species took place in the Miocene and Holocene periods, which was significantly associated with the large-scale uplifts of the Qinling Mountains and adjacent regions. In addition, the geographic distributions of three Pedicularis species have undergone a northward migration from the past to the future. The most important environmental variables affecting the geographic distributions of species were the mean diurnal range and annual mean temperature range. The niche divergence analysis suggested that the three Pedicularis species have similar ecological niches. Among them, P. giraldiana showed the highest niche breadth, covering nearly all of the climatic niche spaces of P. dissecta and P. bicolor. In summary, this study provides novel insights into the divergence and origins of three Pedicularis species and their responses to climate and geological changes in the Qinling Mountains and adjacent regions. The findings have also provided new perspectives for the conservation and management of Pedicularis species. [ABSTRACT FROM AUTHOR]

Changing climatic conditions can shape the strength and extent of the oxygen minimum zone (OMZ). The presence and variability of the OMZ in the Arabian Sea is of importance to the latter's ecosystem. The state of oxygenation has, for instance, an impact on the pelagic and benthic faunal community or the nitrogen and carbon cycles. It is important to understand the dynamics of the OMZ and related marine environmental conditions because of their climate feedbacks. In this study, we combined three independent proxies to reconstruct the oxygenation state of the water column and bottom water in the Gulf of Oman for the past 43 kyr approximately. This multi-proxy approach is done for the first time at the northeastern Oman margin located in the Gulf of Oman. We used bulk sedimentary nitrogen isotopes (δ15N) and the alkane ratio (lycopane +n -C 35)/ n -C 31 and benthic foraminiferal faunal analysis to reconstruct the strength of the OMZ in the water column and bottom water oxygenation, respectively. Our results show that the Gulf of Oman experienced strong pronounced OMZ and bottom water deoxygenation during the Holocene. In contrast, during Marine Isotope Stage 2 (MIS 2), including the Last Glacial Maximum (LGM), the Gulf of Oman was very well ventilated, with a highly diverse benthic foraminiferal community. This may have been caused by stronger wind-induced mixing and better ventilation by oxygen-rich water masses. Our results also show moderate oxygenation during MIS 3, with deoxygenation events during most of the warmer Dansgaard–Oeschger (D–O) events. We propose two distinct oxygenation modes for the Gulf of Oman: (1) a stable period of either strongly pronounced water column OMZ and bottom water deoxygenation or well-oxygenated water column and bottom water conditions and (2) an unstable period of oscillating oxygenation states between moderately oxygenated (stadials) and deoxygenated (interstadials, D–O events) conditions. The unstable period may be triggered by an interstadial Atlantic meridional overturning circulation (AMOC) mode, which is required to initiate D–O events. [ABSTRACT FROM AUTHOR]

Exploring the effects of climate oscillations on the population diversity and structure of endangered organisms in the Three Gorges Reservoir (TGR) area is essential for hydrological environment changes on endangered organism evolution. Myricaria laxiflora is an endemic and endangered shrub restricted to the TGR along the banks of Yangtze River, China. Recently, six natural populations of this species were newly found upstream and downstream of the TGR, whose habitats have been dramatically changed by the summer flooding regulated by large dams. To study the water level fluctuations and climatic shifts on the genetic diversity and genetic differentiation of the six natural populations, 303 individuals from six populations were analyzed based on one nuclear DNA (ITS) and four chloroplast fragments (trnL-F, psbA-trnH, rps16, and rpl16). The phylogenetic tree and significant genetic divergence identified in the cpDNA and ITS with genetic isolation and limited gene flow among regions suggested that the six populations separated well to two groups distributed upstream and downstream. The MaxEnt modeling results indicated that obvious unidirectional eastward migration via Yangtze River gorges watercourse mediated from Last Interglacial to Last Glacial Maximum were showed with the narrow scale distributions of six remnant populations and nine extirpated populations. The initial habitat fragmentation could be triggered by the accumulation of local habitat loss of the impoundment of the TGR during the Present period and might remain stable restoration with bidirectional diffusion in the Future. Divergences among M. laxiflora populations might have been induced by the drastic changes of the external environment and limited seed/ pollen dispersal capacity, as the results of long-term ecological adaptability of summer flooding stress. The haplotypes of nuclear gene could be used for population's differentiation and germplasm protection. This identified gene flow and range dynamics have provided support for the gene-flow and geology hypothesis. It is also crucial for rescuing conservation to understand the impact of environmental dynamics on endangered organism evolution. [ABSTRACT FROM AUTHOR]