Boreas最新文献

{"title":"A North Greenland-wide in situ cosmogenic 14C ice sheet chronology since the Lateglacial","authors":"Anne Sofie Søndergaard,&nbsp;Astrid Rosenberg,&nbsp;Mads Faurschou Knudsen,&nbsp;Kristina Hippe,&nbsp;Marcus  Christl,&nbsp;Negar Haghipour,&nbsp;Olivia Steinemann,&nbsp;Kurt H. Kjær,&nbsp;Nicolaj Krog Larsen","doi":"10.1111/bor.70029","DOIUrl":"https://doi.org/10.1111/bor.70029","url":null,"abstract":"<p>Knowledge of the glacial history of the North Greenland Ice Sheet is crucial due to its high sensitivity to climate change. However, because the ice sheet in this region is predominantly cold-based, resulting in low erosion rates, using ¹⁰Be exposure dating to establish reliable ice sheet chronologies has proven very challenging due to nuclide inheritance. In this study, we measure 16 rock samples for their <i>in situ</i> ¹⁴C concentration, most of which already showed ¹⁰Be nuclide inheritance, resulting in apparent exposure ages pre-dating the most recent deglaciation. We combine our new results with seven already published <i>in situ</i> ¹⁴C exposure ages to build a North Greenland-wide <i>in situ</i> ¹⁴C ice sheet chronology based on a total of 20 boulder and three bedrock samples. Resulting <i>in situ</i> ¹⁴C ages range from 4.8 to 22.4 ka, and more than half of our <i>in situ</i> ¹⁴C exposure ages show signs of excess nuclides, pre-dating the most recent deglaciation at individual sample sites. We believe the excess nuclides could be a result of limited erosion during the Last Glacial Maximum (LGM) and a combination of pre-LGM exposure, supraglacial pre-deposition exposure and possibly thin ice cover. Our new large-scale <i>in situ</i> ¹⁴C data set contributes important knowledge on the glacial history of North Greenland and ice-bed properties in this region. Despite challenges, all <i>in situ</i> ¹⁴C exposure ages except two are younger than their ¹⁰Be counterpart, which highlights the potential and necessity of <i>in situ</i> ¹⁴C exposure dating in regions with cold-based ice and low erosion rates.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 2","pages":"327-339"},"PeriodicalIF":2.9,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147686284","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":"Morphology and distribution of lakes under the Laurentide Ice Sheet: implications for ice flow dynamics","authors":"Sarah M. Principato,&nbsp;Carissa M. Mobley","doi":"10.1111/bor.70034","DOIUrl":"https://doi.org/10.1111/bor.70034","url":null,"abstract":"<p>This study examines the distribution and morphology of lakes under the Laurentide Ice Sheet (LIS) to investigate relationships with ice flow velocity, bedrock and basal thermal regime. Palaeo-ice streams and lobes were important components of the LIS, and properties of lakes in those regions are quantified at high resolution. Lake polygon shapefiles obtained from the HydroLAKES database contain data including water depth, volume and elevation. ArcGIS Pro is used to measure lake area, length, width, elongation, orientation, parallel conformity, density and packing. Approximately 982 282 natural lakes were identified in the region of North America covered by the maximum extent of the LIS during the Last Glacial Maximum. Density of lakes is highest in terrestrial regions surrounding Hudson Bay, and lake density decreases closer to the ice-sheet margin. Packing shows similar patterns to density with the exceptions of regions covered by remnants of proglacial lakes and non-glacial lakes. Close examination of density and packing under palaeo-ice streams and lobes shows statistically significant differences, with greater lake density and packing under palaeo-ice streams than lobes. Bedrock substrate also plays a key role in lake density and packing, with higher lake density under palaeo-ice streams flowing over the Canadian Shield compared with density and packing of lakes under palaeo-ice streams flowing on sedimentary bedrock. Lakes under palaeo-ice streams have higher parallel conformity than lobes, with orientation in both following ice flow paths. Elongation ratios of lakes under palaeo-ice streams and lobes are similar. Regions with high lake density are associated with intense ice scouring on the Canadian Shield, while regions with low lake density on sedimentary bedrock suggest a transition from initially high erosion of soft-bedded terrain followed by depositional processes dominating. High parallel conformity of lakes under palaeo-ice streams provides evidence for fast ice flow, similar to the presence of mega-scale glacial lineations. Quantifying lake morphology and distribution under the LIS provides a useful proxy for ice-sheet dynamics and may help better understand conditions under modern ice sheets, especially in regions of fast ice flow.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 2","pages":"422-442"},"PeriodicalIF":2.9,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147686130","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":"Fossil bears break free from inhibitory cascade constraints at least twice (Ursus minimus and Ursus deningeri) caused by dietary adaptations","authors":"Anneke H. van Heteren,&nbsp;A. Stefanie Luft","doi":"10.1111/bor.70044","DOIUrl":"https://doi.org/10.1111/bor.70044","url":null,"abstract":"<p>The inhibitory cascade model (ICM) predicts relative mammalian molar size and shows a relationship between relative molar size and diet. Bears do not follow the ICM. The aims of this study are to determine which bears, if any, adhere to the ICM, and to assess the evolution of dental development in bears to determine when and why their developmental pattern changed. Molars were measured with sliding callipers and occlusal surface area was taken as a proxy for molar size. An ICM morphospace was created with relative m2 and m3 size on the <i>x</i>- and <i>y</i>-axes, respectively. Our findings indicate that there are two deviations from the ICM. The first takes place between <i>Ursus boeckhi</i> and <i>Ursus minimus</i> and is attributed to a reduction in inhibitors in m1. We suggest the term ‘partial ICM’ to describe the developmental pattern of bears following the first deviation, as their distribution in morphospace runs parallel to the ICM yet is shifted towards a disproportionately larger m2 associated with increased omnivory. The second break takes place between <i>Ursus minimus</i> and <i>Ursus deningeri</i> and is caused by a reduction in inhibitors in m2 resulting in a shift towards disproportionately larger m3 associated with increased herbivory. The two breaks in the established developmental pattern of the ICM are linked to dietary adaptations that can be traced to environmental change, showing the effects of the environment on development on evolutionary time scales.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 2","pages":"503-516"},"PeriodicalIF":2.9,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147686339","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":"Unravelling the evolution of the Frébouge polygenetic cone in Val Ferret (Mont Blanc Massif)","authors":"Catharina Dieleman,&nbsp;Philip Deline,&nbsp;Susan Ivy Ochs,&nbsp;Patricia Hug,&nbsp;Jordan Aaron,&nbsp;Marcus  Christl,&nbsp;Naki Akçar","doi":"10.1111/bor.70042","DOIUrl":"https://doi.org/10.1111/bor.70042","url":null,"abstract":"<p>Proglacial settings in the Alps are typically polygenetic, often characterized by a complex and discontinuous interplay between glacial, fluvial and gravitational processes. These processes yield high volumes of sediments, which usually exceed their transportation capacity. The excessive proglacial sediment load leads to accumulation on slopes, and thus, to subsequent failures such as rock avalanches. The northern slopes of the Ferret and Veny valleys in the Mont Blanc Massif are home to several polygenetic cones and are a stunning field laboratory for the exploration of the interplay between the glacial, fluvial and gravitational processes. This study investigates a well-preserved polygenetic cone, the Frébouge cone, to disentangle the geomorphic processes that contributed to its formation and to reconstruct its evolution. To achieve these goals, detailed field and remote mapping, ¹⁰Be surface exposure dating, and runout modelling with DAN3D^® were used. The geomorphological map revealed complex interactions of glacial, fluvial, debris flow, as well as rock and snow avalanche processes. The established chronology indicates two major episodes of debris flows, the first one at <i>c</i>. 2 ka, and the second at <i>c</i>. 1 ka. In addition, a rock mass with a maximum volume of up to 12±3 Mm³ collapsed in the upper reaches of the cone at 1.3±0.1 ka and overran the cone, travelling more than 100 m up onto the opposite valley slope. Afterwards, the Frébouge Glacier overrode the cone several times leaving moraines and till, reaching its maximum extent <i>c</i>. 300 years ago. This study underscores the untwisting of the complex interaction of surface processes in the Alpine valleys, which are prone to hit the urban areas and infrastructures.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 2","pages":"454-475"},"PeriodicalIF":2.9,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70042","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147686076","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":"Debris at the edge: sedimentological dynamics of Hintereisferner's evolving terminus and glacial forefield, Austrian Alps","authors":"Paulina Mejías Osorio,&nbsp;Ricarda Wohlschlägl,&nbsp;Thomas M. Vandyk,&nbsp;Sara Karbacher,&nbsp;Bethan Joan Davies,&nbsp;Daniel Paul Le Heron","doi":"10.1111/bor.70046","DOIUrl":"https://doi.org/10.1111/bor.70046","url":null,"abstract":"<p>The interaction between glaciers and the debris accumulating on their surfaces is critical as the Earth warms, with consequences for ice dynamics, hydrology and mass balance together with slope and sedimentary processes. Understanding this interaction is necessary since it influences ablation rates, sediment and meltwater pathways. The Hintereisferner glacier (Austrian Alps) has over a century's worth of observations and while mostly a clean and debris-free glacier, the last kilometre is becoming covered by debris. In this study, we present new geomorphological and sedimentological work, including glacier debris and forefield mapping that sheds light on the temporal and spatial accumulation of debris. The characterization of the forefield and terminus of the Hintereisferner permits identification of sediments and landforms, which were classified into landsystems. The subglacial/glaciofluvial dominated forefield has been exposed in the past 25 years, uncovering sections that demonstrate shifting channels with oscillating energy conditions in contact with till. The supraglacial landsystem consists of ablation cones and transverse ridges (both with low preservation potential), associated with crevasse infill by meltwater and englacial debris emergence, respectively. Additionally, the supraglacial system includes debris cover units with a paraglacial component that correspond to debris derived from both gravitational processes and heavy precipitation events, modifying the supraglacial meltwater system. It is expected that debris flows will be the main contributor of debris onto the glacier surface, that cauldron structures will continue to develop and eventually collapse, and most landforms will not be preserved as the forefield evolves. A coupled understanding of the recent deglacial landscape, together with the processes of debris accumulation on the glacier margin requires a rigorous mapping approach, which should be widely applicable to other mountain glaciated terrains.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 2","pages":"542-559"},"PeriodicalIF":2.9,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70046","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147686188","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":"Exploring dietary adaptations in Ursus minimus: a 3D geometric morphometric analysis of the mandible","authors":"Anneke H. van Heteren","doi":"10.1111/bor.70036","DOIUrl":"https://doi.org/10.1111/bor.70036","url":null,"abstract":"<p>The extinct bear <i>Ursus minimus</i>, which lived in Europe during the Pliocene and possibly Early Pleistocene, is considered the common ancestor of all modern Ursini. <i>U. minimus</i> is thought to have been omnivorous, with a preference for invertebrates. The present study aims to investigate its potential adaptations to this diet using 3D geometric morphometrics. Landmarks for 3D digitization of the mandible were selected to represent functional morphology. Extant and extinct Quaternary Ursidae were digitized as a comparative reference sample, followed by generalized Procrustes superimposition, with the data subsequently corrected for allometry through a pooled regression analysis. Principal component analysis was performed on the regression residuals and a phylogeny mapped onto the morphospace. The present study reveals that the mandibular morphology of <i>U. minimus</i> aligns more closely with omnivorous species than with insectivorous bears, challenging the idea of its insectivorous tendencies. As the common ancestor of modern Ursini, <i>U. minimus</i>' omnivorous dietary flexibility implies that <i>U. minimus</i> possessed a generalized adaptive strategy, which could have served as the foundation from which more specialized dietary forms later evolved.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 2","pages":"443-453"},"PeriodicalIF":2.9,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147686153","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 limpet's eye view of post-glacial isostasy: fixed biological indicators provide new sea-level index points for the Mid-Holocene relative highstand in eastern Northern Ireland","authors":"Michael J. Simms,&nbsp;Paula J. Reimer","doi":"10.1111/bor.70048","DOIUrl":"https://doi.org/10.1111/bor.70048","url":null,"abstract":"<p>Empirical data for Holocene relative sea level (RSL) changes around the coast of north-eastern Ireland are sparse. Fixed biological indicators (FBIs), in the form of bioerosional marks made by limpets (<i>Patella</i>) and endolithic traces of other intertidal/subtidal organisms, are preserved significantly above present mid-tide level on a limestone cliff at Portmuck, in Co. Antrim, Northern Ireland. The limpet marks indicate a mid-tide level (MTL) for the Mid-Holocene relative highstand (MHRH) at +7.8±0.55 m relative to MTL today. This is &gt;3 m higher than previous empirical data for the region but is consistent with recent glacial isostatic adjustment (GIA) models. Shells of intertidal molluscs (<i>Patella</i>, <i>Littorina</i> and <i>Nucella</i>) recovered from fissures below the limpet marks show a significant spread of ¹⁴C ages, with the oldest a close match for the date of the MHRH but others as much as 2750 years younger. They indicate that RSL fell no more than ~2.5 m in that time from a highstand at ~6.3 cal. ka BP, a pattern comparable to that seen in southern Scotland but 1.5–2 ka later. This chronological offset is consistent with models that predict shoreline diachroneity in moving away from the centre of isostatic uplift in southern Scotland.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 2","pages":"585-599"},"PeriodicalIF":2.9,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70048","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147686358","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":"Untangling nutrient co-regulation of ombrotrophic peatland development","authors":"Richard C. Chiverrell,&nbsp;Daniel N. Schillereff,&nbsp;Fiona E. Russell,&nbsp;Julie Valentine,&nbsp;Jason R. Kirby,&nbsp;David M. Wilkinson,&nbsp;John F. Boyle","doi":"10.1111/bor.70031","DOIUrl":"https://doi.org/10.1111/bor.70031","url":null,"abstract":"<p>Ombrotrophic peatlands are the largest terrestrial store of global carbon (C). While hydroclimate controls over peatland development are well known, the importance of nutrient fluxes has been researched less. Atmospheric nutrient fluxes to peatlands have increased with human activity in recent centuries. Here we explore the interplay of nutrient and hydroclimate drivers at Holcroft Moss (northwest England), a lowland ombrotrophic peatland typical of many across northern Europe. Parallel multi-proxy characterization of the organic matter composition and nutrient accumulation rates shows a sequence dominated by switches between fresh less decomposed layers and more decomposed peat containing abundant recalcitrant organic compounds. Hydroclimate variability governs much of the stratigraphy. Shifts to wetter conditions appear to trigger periods of reduced decomposition centred <i>c</i>. 3450, 2600–2500, 2225, 2060, 2000, 1825, 1650–1610, 1540, 1480, 1260, 1125, 1000, 740–720 and 600–550 cal. a BP. In addition, elevated N and P deposition beginning ~1000 cal. a BP, accelerating ~500 years cal. a BP, has led to changes in the co-behaviour between hydroclimate, peat composition and C accumulation rates. Long-term carbon/nutrient accumulation rates at Holcroft Moss are high compared to other UK peatlands measured to date. Higher nutrient fluxes from human activities will persist through the 21st century, with the implications for long-term peatland resilience and this important carbon sink unclear. Restoration and management of peatlands understandably focus on hydrology and vegetation, but we show a parallel need to consider nutrient deposition, which will vary site by site.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 2","pages":"384-404"},"PeriodicalIF":2.9,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147686265","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":"Late-Holocene evolution of a small Sub-Arctic glacier, Gljúfurárjökull (Tröllaskagi, northern Iceland)","authors":"Nuria Andrés,&nbsp;José M. Fernández-Fernández,&nbsp;David Palacios,&nbsp;Irene Schimmelpfennig,&nbsp;Leopoldo G. Sancho,&nbsp;Skafti Brynjólfsson,&nbsp;Þorsteinn Sæmundsson,&nbsp;Wesley R. Farnsworth,&nbsp;Luis M. Tanarro,&nbsp;Mariano Brito,&nbsp;Javier Santos-González,&nbsp;Rosa B. González-Gutiérrez,&nbsp;ASTER Team (Georges Aumaître, Karim Keddadouche)","doi":"10.1111/bor.70030","DOIUrl":"https://doi.org/10.1111/bor.70030","url":null,"abstract":"<p>Gljúfurárjökull, located on the Tröllaskagi Peninsula in northern Iceland, is a small glacier approximately 3.8 km in length. This study analyses the glacier's evolution through a combination of methods including: (i) geomorphological mapping, (ii) Cosmic-Ray Exposure (CRE) dating, (iii) lichenometry and (iv) palaeoglacier reconstruction (volume, extent and Equilibrium Line Altitude (ELA)) for each identified ice-marginal position. The mean CRE ages obtained are as follows: Glacial Phase 1: no samples available for CRE dating; Glacial Phase 2: 2.6±0.5 ka (<i>n</i> = 2); Glacial Phase 3: 3.2±1.1 ka (n = 7); Glacial Phase 4: 2.5±0.2 ka (<i>n</i> = 2); Glacial Phase 5: between 2.1 ka and a few hundred years. Lichenometry results for surfaces older than 130 years show inconsistencies both internally and in comparison with CRE ages. However, for the most recent glacier margins, lichenometric dates are coherent and align with historical photographic evidence. Accordingly, the ages proposed for glacier marginal positions 6 and 7 are 1899/1904 CE and 1912/1917 CE, respectively, slightly predating position 8, which is documented in aerial photographs from 1946 CE. The millennial- to centennial-scale evolution of Gljúfurárjökull outlined in this study is consistent with the patterns observed in debris-free glaciers across Tröllaskagi, as well as in many Icelandic and Arctic glaciers. Notably, the Little Ice Age (LIA) advance at Gljúfurárjökull was less extensive than earlier Neoglacial advances, a trend common in the Sub-Arctic and Arctic regions. Since the end of the LIA, the glacier has experienced a general retreat, interrupted only by a brief advance during the 1980s–1990s—again mirroring broader Arctic glacial behaviour. Overall, this study underscores the high sensitivity of Gljúfurárjökull to climatic fluctuations during the Late Holocene. The application of CRE dating reveals that the glacier's evolution aligns closely with patterns observed in other Icelandic and Arctic glaciers.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 2","pages":"356-383"},"PeriodicalIF":2.9,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147686916","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":"Coastal evolution, environmental change and carbon storage in the Thung Prong Thong Mangrove, eastern Gulf of Thailand","authors":"Sakonvan Chawchai,&nbsp;Smith Leknettip,&nbsp;Naomi Seaton,&nbsp;Kannika Wangritthikraikul,&nbsp;Nathalie Dubois,&nbsp;Ludvig Löwemark,&nbsp;Pei-Ling Wang,&nbsp;Frank Preusser","doi":"10.1111/bor.70033","DOIUrl":"https://doi.org/10.1111/bor.70033","url":null,"abstract":"<p>Palaeoenvironmental records along the eastern coast of Thailand remain sparse, with only a few studies attempting to reconstruct past climatic and environmental conditions. However, additional palaeoenvironmental, palaeoclimatic and sea-level records are needed to improve our understanding of coastal evolution and local environmental changes. This study investigates mangrove sediment from the Prasae Estuary Mangrove (PEM) complex in Rayong Province, eastern Thailand. The PEM complex is an estuarine fringing mangrove influenced by the mixed tidal-fluvial dynamics of the Prasae River mouth. The region's low-relief geomorphology includes intertidal mudflats, wetlands and relict sand deposits associated with relatively high sea levels during the Late Holocene. To reconstruct sea-level changes, beach ridge deposits from the area were dated using optically stimulated luminescence. The results indicate a progressive seaward-younging pattern of the beach ridges, implying shoreline progradation of at least 2 km over the past 1240±40 years in response to a gradual marine regression of less than 2 m during the Late Holocene. The formation of these beach ridges created favourable conditions for the mangrove forest to colonize the Thung Prong Thong area between 690 and 210 years ago. Geochemical analyses of mangrove sediments, including elemental composition (C, N) and δ¹³C values, indicate a predominance of terrestrial organic matter input, primarily from freshwater discharge and mangrove leaf litter. The accumulation of substantial amounts of organic carbon in the soil highlights the role of mangroves as important carbon sinks. Over the past 38 years, land-use changes, particularly the conversion of mangrove areas into shrimp farms, have led to an estimated carbon release of approximately 14 800 Mg C (mega gram carbon = 1000 kg) to the atmosphere. However, conservation efforts have at the same time contributed to the expansion of mangroves and increased carbon sequestration along the PEM coast, resulting in a net increase in carbon stock accumulation of ~17 500 to ~22 800 Mg C. Given the substantial impact of land-use changes on carbon stocks, this study underscores the importance of sustainable land management and long-term monitoring of coastal mangrove ecosystems.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 2","pages":"405-421"},"PeriodicalIF":2.9,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147686266","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}