Boreas最新文献

{"title":"Response to Comment on ‘Automatic identification of streamlined subglacial bedforms using machine learning: an open-source Python approach’","authors":"Marion McKenzie, Ellianna Abrahams, Fernando Pérez, Ryan Venturelli","doi":"10.1111/bor.70004","DOIUrl":"https://doi.org/10.1111/bor.70004","url":null,"abstract":"<p>Li <i>et al</i>. (<span>2025</span> this issue) state that they identify areas for improvement to our development of bedfinder through including more data sets at training, evaluating our filtering methods, and exploring modular approaches of the tool. Here we respond to these Comments by highlighting where we have already addressed each of these areas within our work and notably, our supporting information (Abrahams <i>et al</i>. <span>2024</span>). In our paper, we describe that bedfinder is an inherently modular tool, allowing a user to choose which components of the pipeline might be useful to them. Furthermore, bedfinder already allows a user to customize the choice to over- or under-predict a glacially derived bedform assignment. In Abrahams <i>et al</i>. (<span>2024</span>) we previously justified why we made the choice to over-predict, emphasizing the need for manual post-processing, which we reiterate here. Finally, we reshare statements from the ‘Model limitations’ section of Abrahams <i>et al</i>. (<span>2024</span>) where we also recommend incorporating additional data in future tool creation to strengthen our approach.</p><p>The objective of Abrahams <i>et al</i>. (<span>2024</span>) was to build an open-source tool that would allow for the automatic detection of glacially derived streamlined subglacial bedforms, based on the previous successes of manual approaches (e.g. Clark <span>1993</span>; Greenwood & Clark <span>2008</span>; Spagnolo <i>et al</i>. <span>2014</span>; Ely <i>et al</i>. <span>2016</span>; Principato <i>et al</i>. <span>2016</span>; Clark <i>et al</i>. <span>2018</span>). To develop this tool, we used Random Forest (Breiman <span>2001</span>), XGBoost (Chen & Guestrin <span>2016</span>), and an ensemble average of these two model fits on a publicly available training data set of nearly 600 000 data points across the deglaciated Northern Hemisphere (McKenzie <i>et al</i>. <span>2022</span>). Li <i>et al</i>. (<span>2025</span>) suggest a constructive critique to our approach stating our work should include more data sets at training, further evaluate our filtering methods, and explore better modularizing bedfinder. However, these suggestions have either already been implemented as existing features of bedfinder (i.e. modularity of pipeline components and tunability of bedform predictions to the needs of the user) or we have already named them in our study as known limitations of the tool that will require wider community participation (the creation of larger, more nuanced machine learning data sets for model training).</p><p>Abrahams <i>et al</i>. (<span>2024</span>) outlined the limitations of the presented approach in the section ‘Model limitations’. There, we state that the ‘TPI tool used to compile our training set performs most poorly in regions with highly elongate bedforms with low surface relief (McKenzie <i>et al</i>. <span>2022</span>)’ (i.e. bedforms across crystalline bedrock surfaces) (Abrah","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 2","pages":"277-280"},"PeriodicalIF":2.4,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reassessing the predictive power of bedfinder: insights into machine learning for subglacial bedform detection – Comments on ‘Automatic identification of streamlined subglacial bedforms using machine learning: an open-source Python approach’","authors":"Ming Li, Huanyu Zhao, Tianfei Yu","doi":"10.1111/bor.70005","DOIUrl":"https://doi.org/10.1111/bor.70005","url":null,"abstract":"<p>The integration of machine learning (ML) into geomorphological research presents significant opportunities for automating the identification of streamlined subglacial bedforms. In their study, Abrahams <i>et al</i>. (<span>2024</span>) introduce bedfinder, an open-source Python tool designed to detect subglacial features with high efficiency. While the tool demonstrates promise, this discussion highlights critical challenges and areas for refinement. The representativeness of the training data set, dominated by sedimentary bed conditions, limits the model's generalizability to regions with diverse bedrock compositions. Additionally, the reliance on binary classifications oversimplifies complex geomorphic settings, reducing the model's adaptability. Performance metrics such as F1 scores, though favourable, warrant cautious interpretation due to class imbalances that may skew predictions. Furthermore, the integration of filtering techniques, while enhancing precision, raises concerns about potential biases from manual data curation. To enhance scientific rigour, future efforts should incorporate diverse data sets, conduct comprehensive evaluations of filtering methods, and explore modular approaches for greater applicability. Addressing these challenges will not only strengthen bedfinder but also contribute to the evolving role of ML in advancing glacial and geomorphological research. This contribution provides a constructive critique to guide future improvements and interdisciplinary applications of this innovative tool.</p><p>Abrahams <i>et al</i>. (<span>2024</span>) present a cutting-edge approach to the identification of streamlined subglacial bedforms, which are crucial in understanding past glacial dynamics and their impact on geomorphology. The authors have developed an open-source Python tool, bedfinder, that employs supervised ML algorithms – Random Forest and XGBoost – to automate the identification of these features across deglaciated landscapes. This tool is an ambitious attempt to enhance efficiency and accuracy in a domain traditionally burdened by labour-intensive, subjective, and time-consuming manual processes. The authors also provide a thorough validation of the model using an extensive data set of known subglacial bedforms from various regions in the Northern Hemisphere.</p><p>While the study contributes valuable insights into how ML can automate the mapping of complex glacial features, several critical issues arise from the selection of data, the application of ML methods, and the interpretation of results. Here, we will highlight some of these issues and offer suggestions to enhance the scientific robustness of the study and its potential applications. The concerns outlined here include the representativeness of the training data, the challenges in interpreting the performance metrics, and the potential over-simplifications in model design and validation.</p><p>A central issue in Abrahams <i>et al</i>. (<span>2024</span>) ","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 2","pages":"273-276"},"PeriodicalIF":2.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cladocera assemblages indicate environmental gradients of lake productivity and morphometry in central Europe","authors":"Izabela Zawiska,&nbsp;Alex Correa-Metrio,&nbsp;Monika Rzodkiewicz,&nbsp;Jacek Wolski","doi":"10.1111/bor.70001","DOIUrl":"https://doi.org/10.1111/bor.70001","url":null,"abstract":"<p>Lakes play a vital role in numerous human activities, yet extensive economic development has led to significant pollution and nutrient enrichment, resulting in widespread eutrophication and ecological disruption. To accurately assess the current state of lakes, it is essential to understand their historical, pre-impact conditions. Palaeolimnological methods, including the analysis of subfossil Cladocera, offer a valuable tool for studying lake ecosystems over extended timeframes that go beyond modern instrumental records. Our research aims to identify the primary environmental factors that influence the distribution of individual Cladocera species and evaluate the systematic patterns within species assemblages to enhance their use as ecological indicators. This study presents an analysis of Cladocera assemblages based on environmental surveys conducted in 64 lakes across northeastern Poland. Principal component analysis revealed that the two dominant factors driving variability in the dataset are lake trophic state, indicated by total phosphorus (TP) levels, and lake depth. Species distributions across these gradients showed a turnover, reflecting distinct environmental preferences. Further, end member (EM) analysis identified five distinct assemblages of Cladocera, each associated with specific combinations of trophic status and lake size. EM1 is associated with higher trophic states, while EM2, EM3 and EM4 are indicative of medium to low trophic states. EM5 is independent of trophic status, associated with large and deep-water bodies.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 2","pages":"258-272"},"PeriodicalIF":2.4,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drivers of glacially induced fault reactivation in the Baltic Sea sector of the Tornquist Fan","authors":"Elisabeth Seidel,&nbsp;Holger Steffen,&nbsp;Rebekka Steffen,&nbsp;Niklas Ahlrichs,&nbsp;Christian Hübscher","doi":"10.1111/bor.12689","DOIUrl":"https://doi.org/10.1111/bor.12689","url":null,"abstract":"<p>We analyse the effect of Quaternary glaciations on the complex tectonic pattern within the southwestern Baltic Sea, a sector of the transition zone from the East European Craton to the West European Platform. This area comprises the Caledonian Trans–European Suture Zone in the south and the Tornquist Zone in the north. Multiple fault zones in between, with different strike and dip angles, and characters (normal, thrust/reverse, strike-slip), document like scars the alternately transpressional and transtensional stress activities since the Palaeozoic. We determine the strike directions and dip angles of more than 40 potential glacially reactivated faults identified in 2D marine reflection seismic data. Finite element simulations of different glacial isostatic adjustment models provide glacially induced Coulomb failure stress changes (ΔCFS) at the faults over time, starting 200 000 years ago (200 ka, Saalian phase) up to 1000 years into the future. Assuming strike-slip or thrust/reverse background stresses, a potential reactivation of each fault is analysed. The detected reactivation phases are related to the waxing and waning ice masses (Late Saalian ice advances: <i>c.</i> 170–135 ka ago; Weichselian ice advances: 70–60, 45–38, 26–14 ka ago) and point to an activation in front of the ice margin. Comparing the ΔCFS results of the individual faults laterally and over time, we found that the location of the fault, depending on its position during a glacial maximum, has an important effect on its reactivation potential. The closer a fault was located to the former ice margin, the higher was the glacially induced stress during the ice retreat. Based on earlier findings in Germany and Denmark, glacially triggered faults are a typical consequence of the Fennoscandian glaciation throughout northern central Europe, and this also applies to future glaciation phases.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 2","pages":"220-245"},"PeriodicalIF":2.4,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12689","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A synthesis of luminescence and 14C dated dust mass accumulation rates for loess-palaeosol sequences from the Middle Danube Basin","authors":"Zoran M. Perić,&nbsp;Milica G. Radaković,&nbsp;Rastko S. Marković,&nbsp;Slobodan B. Marković","doi":"10.1111/bor.12696","DOIUrl":"https://doi.org/10.1111/bor.12696","url":null,"abstract":"<p>The Middle Danube (Carpathian) Basin is considered to encompass some of the thickest and most complete records of aeolian dust deposition in Europe, covering the last two glacial–interglacial cycles. In this study, independent, published chronologies based on absolute dating methods were compiled for 34 loess-palaeosol sequences and modelled using Bayesian statistics. Mass accumulation rates (MARs) calculated from the Bayesian age models range from 50 to 1922 g m⁻² a⁻¹ with a mean value of 317±35 g m⁻² a⁻¹. The glacial–interglacial changes of the MAR estimates only partially agree with the accepted dust deposition model, where high accumulation rates are observed during the cold glacial stages, while low values are typical for the warmer interglacial periods. There is a rapid increase of MAR values during Marine Isotope Stage (MIS) 2, with the highest deposition in most cases observed ~25–18 ka. During MIS 3, the dust deposition was 1.8 times higher than during MIS 4. Regionally, the MARs appear to be highest in the northern part of the Middle Danube Basin, showing decreasing values towards the south. However, due to a variety of factors such as low dating resolution, age distribution, and biases in the dating method, it is debatable whether these results are representative estimates of atmospheric dust activity in the Middle Danube Basin during MIS 5–MIS 1.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 2","pages":"179-201"},"PeriodicalIF":2.4,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12696","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochronological investigations at the maximum extent of the Fennoscandian Ice Sheet during the Late Weichselian glaciation in northern Germany","authors":"Nikolas Krauß,&nbsp;Andreas Börner,&nbsp;Michael Kenzler","doi":"10.1111/bor.12695","DOIUrl":"https://doi.org/10.1111/bor.12695","url":null,"abstract":"<p>This paper investigates the time-transgressive evolution of the Fennoscandian Ice Sheet (FIS) during the Late Weichselian glaciation. Recent models of the Last Glacial Maximum (LGM) strongly challenge a synchronous development of the FIS in the SW Baltic Sea area. Especially in northern Germany, a time-transgressive LGM is controversial. We present a new set of optically stimulated luminescence (OSL) ages, from sediments deposited at locations previously ascribed to the LGM main stationary line, from which numerical age data have not been published so far. The aim of this study was to contribute to the research on the maximum Weichselian ice extent in northern Germany, and to close the gap between Denmark in the north and the area in Germany and Poland in the SE, for which numerical age data of the LGM extent of the FIS are available. Samples were taken from sandur deposits proximal to the former ice margin. In total nine OSL samples were taken and analysed on quasi-single-grain level, taking into account possible effects of insufficient bleaching of sample material. With an average age of ~23±1 ka, the samples indicate LGM sandur formation during Marine Isotope Stage (MIS) 2. Our dating provides new insights into Late Weichselian (MIS 2, 27–11.7 ka) ice-sheet dynamics and strongly challenge a synchronous development of the FIS in the SW Baltic Sea area. The integration of our results into regional models argues for a small-scale asynchronous extent of the last FIS in northern Germany.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 2","pages":"246-257"},"PeriodicalIF":2.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12695","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-proxy reconstruction of Lateglacial and Holocene mountain vegetation dynamics in Uri, Central Switzerland","authors":"Ursula Huonder,&nbsp;Laura Dziomber,&nbsp;Erika Gobet,&nbsp;Carolina Senn,&nbsp;Petra Zahajská,&nbsp;Willy Tinner,&nbsp;Christoph Schwörer","doi":"10.1111/bor.12691","DOIUrl":"https://doi.org/10.1111/bor.12691","url":null,"abstract":"<p>In the context of climate change, a long-term perspective is essential to understand future trajectories of mountain vegetation. We analysed the sediment record of Golzerensee (1411 m a.s.l.), a mountain lake in the transitional zone between the montane and subalpine vegetation belt in Uri, Central Switzerland. We reconstructed past vegetation responses to anthropogenic impact, fire activity and climatic changes dating back to <i>c</i>. 14 550 cal. a BP using pollen, stomata, macrofossil and microcharcoal analyses. The tree line, composed of <i>Betula</i> and <i>Pinus sylvestris</i>, reached Golzerensee during the Allerød <i>c</i>. 13 200 years ago, but tundra vegetation re-expanded during the Younger Dryas cooling (12 800–11 700 cal. a BP). With the rapid temperature increase at the onset of the Holocene, a closed forest established within a few decades around the study site. Concurrently, temperate taxa (<i>Ulmus</i>, <i>Tilia</i>, <i>Acer</i>, <i>Corylus avellana</i>) increased in the lowlands, likely reaching the elevation of the lake. <i>Abies alba</i> established locally during the Holocene Thermal Maximum (HTM) at 9600 cal. a BP and dominated closed, montane forests, delaying the westward expansion of <i>Picea abies</i> that established only from <i>c</i>. 7700 cal. a BP onwards. The concomitant occurrence of cultural indicator taxa, as well as an increase in charcoal influx and fungal dung spore concentrations suggest that human impact has facilitated the expansion of <i>Picea abies</i> by negatively affecting important competitors such as <i>Abies alba</i> through fire and browsing disturbance. With rising temperatures due to current climate change, <i>Abies alba</i> and other temperate species may regain their former relevance, leading to diverse mixed forests that were abundant during the HTM <i>c</i>. 10 000–5000 cal. a BP. However, future forest composition and landscape diversity will also be influenced by browsing disturbance and land use management.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 2","pages":"202-219"},"PeriodicalIF":2.4,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12691","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lateglacial and Holocene chronology of climate-driven postglacial landscape evolution in northeast Greenland","authors":"Julia Garcia-Oteyza,&nbsp;Marc Oliva,&nbsp;David Palacios,&nbsp;Jose Maria Fernández-Fernández,&nbsp;Irene Schimmelpfennig,&nbsp;Marcelo Fernandes,&nbsp;Santiago Giralt,&nbsp;Dermot Antoniades,&nbsp;Vincent Jomelli","doi":"10.1111/bor.12683","DOIUrl":"https://doi.org/10.1111/bor.12683","url":null,"abstract":"<p>The Greenland Ice Sheet is highly sensitive to climate change, leading to significant retreat along its edges. This rapid ice loss contributes to rising sea levels and impacts the Earth's climate stability. Understanding the extent of recent glacier retreat is crucial in order to determine if it is unprecedented or within ranges of natural variability. Palaeoenvironmental studies aim to identify past glacial phases and landscape changes using advanced dating methods such as cosmic ray exposure (CRE) dating. In NE Greenland, CRE dating has helped establish the timing of glacial oscillations, yet a comprehensive understanding of glacial fluctuations during specific periods still needs to be developed. This study aims to chronologically constrain the postglacial landscape evolution of two NE Greenland valleys from the Young Sund–Tyrolerfjord area (74°N, 20–25°E) from the onset of deglaciation and throughout the Holocene to better understand glacial and postglacial changes. The chronological framework relies on 27 ¹⁰Be cosmic-ray exposure ages that constrain our interpretation of the geomorphological features in both valleys. Inconsistencies were observed in the ages dataset, highlighting potential bias associated with nuclide inheritance and post-glacial dynamics. Despite limitations, the CRE results confirm the general pattern observed in NE Greenland: (i) major deglaciation and disconnection of glaciers from the main glacial systems during the Lateglacial and Early Holocene with a rapid but not homogeneous deglaciation within the range from ~14.3 to 11.9 ka; (ii) no evidence of glacial activity during the Middle Holocene, probably associated with the withdrawn position of the ice masses’ fronts; and (iii) glacier expansion during the Late Holocene, with a Little Ice Age advance as the last significant period of glacial regrowth.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 1","pages":"105-124"},"PeriodicalIF":2.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12683","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143117454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interpreting depositional environments from modern floodplain sediments using optically stimulated luminescence","authors":"Abigail L. Langston,&nbsp;Abbey L. Marcotte,&nbsp;Christina M. Neudorf,&nbsp;Kathleen Rodrigues,&nbsp;Amanda Keen-Zebert","doi":"10.1111/bor.12679","DOIUrl":"https://doi.org/10.1111/bor.12679","url":null,"abstract":"<p>We investigate how luminescence signals imprinted on fluvial sediments vary depending on the depositional environment and vary through time in the same river. We collected sediment samples from four geomorphically distinct locations on the modern floodplain and modern point bar on the Buffalo River in northwest Arkansas, USA, in order to determine if different depositional environments are associated with distinct bleaching characteristics in the sediments. Our analysis revealed that all samples from different depositional environments yielded ages consistent with modern deposition. The samples collected from the floodplain and bar head contained a higher proportion of grains with residual doses, indicative of incomplete bleaching during transport, while samples from the mid-bar and bar tail appeared well bleached. Our results are particularly intriguing for two significant reasons. First, they highlight distinct equivalent dose distributions in different depositional environments. Second, they shed light on an intriguing relationship: despite generally well-bleached modern floodplain samples, ancient sediments from corresponding terraces displayed equivalent dose (D_e) distributions that suggest partial bleaching in some cases. This research contributes to the growing body of work that seeks to establish a relationship between luminescence properties and sediment transport processes and offers valuable insight into how luminescence signals vary locally in modern fluvial deposits, which can help guide the interpretation of older fluvial deposits.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 1","pages":"14-33"},"PeriodicalIF":2.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12679","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143114653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vegetation response to Early Holocene cooling events in the Moervaart region (northwestern Belgium)","authors":"Nelleke van Asch,&nbsp;Marjolein Gouw-Bouman,&nbsp;Maaike Zwier,&nbsp;Hanneke Bos,&nbsp;Philippe Crombé","doi":"10.1111/bor.12680","DOIUrl":"https://doi.org/10.1111/bor.12680","url":null,"abstract":"<p>A high-resolution palynological record from northwest Belgium is presented. The record encompasses the second part of the Younger Dryas and the Early Holocene. The basal part of the pollen record reflects a relatively open landscape, characteristic for the Younger Dryas. The transition to the Holocene is marked by an expansion of birch woodland, followed by an expansion of pine in the Late Preboreal (~11.2–10.7 cal. ka BP). Subsequently, the record shows an expansion of mixed deciduous forest with hazel, elm and oak, characteristic for the Boreal (~10.7–8.6 cal. ka BP). Early Holocene forest expansion was interrupted by a number of short-lived fluctuations, presumably driven by climatic changes. The most distinct event is the Rammelbeek phase (~11.4–11.2 cal. ka BP), during which forest development was temporarily interrupted in favour of grasses, while wildfires increased. Following this climatic event, hunter-gatherers returned to the area after a period of almost 1.5 millennia of low population density. They most likely were attracted by the increased temperatures and abundance of edible plants present in the birch-pine forests and on the banks of the river Kale/Durme. A temporary expansion of pine during the Boreal (~10.7–8.6 cal. ka BP) may correspond with the 9.3-ka event. At this time, superimposed on a trend of gradual infilling of the channel, a temporary change to drier conditions is observed. The significant drop in the number of prehistoric sites in the Moervaart region clearly cannot be attributed to this short-term climatic event alone but was most likely caused by a combination of environmental changes, such as the decreasing availability of hazelnuts as well as freshwater and edible (semi-)aquatic plants as the Kale/Durme river gradually turned dry. The study provides insight into, partly climate-driven, Early Holocene environmental changes and the effect this may have had on human occupation.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 1","pages":"140-155"},"PeriodicalIF":2.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12680","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143114502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}