Pub Date : 2023-07-07DOI: 10.1177/09596836231183062
A. Koutsodendris, A. Brauer, O. Friedrich, R. Tjallingii, V. Putyrskaya, B. Hennrich, R. Kühn, E. Klemt, Jörg Pross
To reconstruct naturally and anthropogenically induced environmental change in SE Europe since the Little Ice Age, we have examined five partially varved sediment cores from coastal Lake Vouliagmeni, Greece. Our reconstructions are based on a multi-proxy approach including microfacies analysis, X-ray fluorescence core scanning, radionuclide dating (210Pb, 137Cs, and 241Am), and palynological analysis (pollen, spores, and dinoflagellate cysts). A 131 -cm-long composite record that encompasses the past c. 300 years reveals 181 varves of endogenic and mixed clastic-biogenic types. The formation of these varves was controlled by seasonal variability in clastic input and primary productivity. The non-varved intervals consist of homogenous lake sediments and turbidite deposits. Based on a chronology developed through radionuclide dating, varve counting and exclusion of turbidites from the sequence, we have compared our proxy data with meteorological data and historical records of earthquakes and human activities. Our results suggest that the surroundings of Lake Vouliagmeni experienced relatively wet conditions during the late solar Maunder Minimum (1645–1715 AD) and relatively dry conditions during the Dalton Minimum (1790–1830 AD), which highlights the hydroclimatic heterogeneity in SE Europe during the Little Ice Age. The evaluation of historical documentation suggests that the majority of the turbidites is related to lake-slope instabilities following earthquake shocks. Human impact on Lake Vouliagmeni includes (i) a change in aquatic biota following the artificial connection of the lake to the sea at c. 1880 AD, and (ii) expansion of agricultural areas and reduction of natural forests around the lake due to population growth over the past 300 years.
{"title":"Natural and human-induced ecosystem change in SE Europe since AD 1700 derived from a partially varved sediment record from Lake Vouliagmeni (Greece)","authors":"A. Koutsodendris, A. Brauer, O. Friedrich, R. Tjallingii, V. Putyrskaya, B. Hennrich, R. Kühn, E. Klemt, Jörg Pross","doi":"10.1177/09596836231183062","DOIUrl":"https://doi.org/10.1177/09596836231183062","url":null,"abstract":"To reconstruct naturally and anthropogenically induced environmental change in SE Europe since the Little Ice Age, we have examined five partially varved sediment cores from coastal Lake Vouliagmeni, Greece. Our reconstructions are based on a multi-proxy approach including microfacies analysis, X-ray fluorescence core scanning, radionuclide dating (210Pb, 137Cs, and 241Am), and palynological analysis (pollen, spores, and dinoflagellate cysts). A 131 -cm-long composite record that encompasses the past c. 300 years reveals 181 varves of endogenic and mixed clastic-biogenic types. The formation of these varves was controlled by seasonal variability in clastic input and primary productivity. The non-varved intervals consist of homogenous lake sediments and turbidite deposits. Based on a chronology developed through radionuclide dating, varve counting and exclusion of turbidites from the sequence, we have compared our proxy data with meteorological data and historical records of earthquakes and human activities. Our results suggest that the surroundings of Lake Vouliagmeni experienced relatively wet conditions during the late solar Maunder Minimum (1645–1715 AD) and relatively dry conditions during the Dalton Minimum (1790–1830 AD), which highlights the hydroclimatic heterogeneity in SE Europe during the Little Ice Age. The evaluation of historical documentation suggests that the majority of the turbidites is related to lake-slope instabilities following earthquake shocks. Human impact on Lake Vouliagmeni includes (i) a change in aquatic biota following the artificial connection of the lake to the sea at c. 1880 AD, and (ii) expansion of agricultural areas and reduction of natural forests around the lake due to population growth over the past 300 years.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44113023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-30DOI: 10.1177/09596836231183057
L. Almaraz-Ruiz, M. Machain-Castillo, A. Sifeddine, A. Ruiz-Fernández, J. Sanchez-Cabeza, A. Rodríguez-Ramírez, P. G. López-Mendoza, M. Mendez‐Millan, S. Caquineau
Changes in marine productivity of the last five centuries in the Gulf of Tehuantepec were investigated using a high-resolution record of diatoms, organic carbon (Corg), total nitrogen (TN), Ni/Al, and Cu/Al. The laminated sediments were dated by using 210Pb and 14C, with a bayesian age model providing a new ΔR = 247 ± 30 years for the bulk sediment. The Little Ice Age (LIA) (~1500 to ~1858 CE) was characterized by the predominance of cold-water and high productivity diatoms (Chaetoceros spores, Thalassionema nitzschioides, Lioloma pacificum, Thalassiosira nanolineata, and Rhizossolenia setigera) and high values of geochemical productivity proxies. A transition period (~1860 to ~1919 CE) toward warmer conditions related to the end of the LIA and the beginning of the Current Warm Period (CWP), was indicated by the appearance of warm-water diatoms (Neodelphineis pelagica, Thalassiosira tenera, and Rhizossolenia bergonii), as well as lower values of Corg, TN, Ni/Al, and Cu/Al. The most recent period of the CWP (~1920 CE to today) was characterized by the increased abundance warm-water taxa (N. pelagica, Cymatodiscus planetophorus, T. tenera, Plagiogramma minus, Nitzschia interruptestriata, and R. bergonii), and by the prevalence of low values of Corg, TN, Ni/Al, and Cu/Al. These changes in productivity during the LIA and CWP were likely driven by changes in solar irradiance and the migration of the Intertropical Convergence Zone. This study highlights the spatial extent of the LIA in the Eastern Tropical North Pacific and contributes to the knowledge of the productivity response to climate in tropical regions.
{"title":"Diatom-based paleoproductivity and climate change record of the Gulf of Tehuantepec (Eastern Tropical Pacific) during the last ~500 years","authors":"L. Almaraz-Ruiz, M. Machain-Castillo, A. Sifeddine, A. Ruiz-Fernández, J. Sanchez-Cabeza, A. Rodríguez-Ramírez, P. G. López-Mendoza, M. Mendez‐Millan, S. Caquineau","doi":"10.1177/09596836231183057","DOIUrl":"https://doi.org/10.1177/09596836231183057","url":null,"abstract":"Changes in marine productivity of the last five centuries in the Gulf of Tehuantepec were investigated using a high-resolution record of diatoms, organic carbon (Corg), total nitrogen (TN), Ni/Al, and Cu/Al. The laminated sediments were dated by using 210Pb and 14C, with a bayesian age model providing a new ΔR = 247 ± 30 years for the bulk sediment. The Little Ice Age (LIA) (~1500 to ~1858 CE) was characterized by the predominance of cold-water and high productivity diatoms (Chaetoceros spores, Thalassionema nitzschioides, Lioloma pacificum, Thalassiosira nanolineata, and Rhizossolenia setigera) and high values of geochemical productivity proxies. A transition period (~1860 to ~1919 CE) toward warmer conditions related to the end of the LIA and the beginning of the Current Warm Period (CWP), was indicated by the appearance of warm-water diatoms (Neodelphineis pelagica, Thalassiosira tenera, and Rhizossolenia bergonii), as well as lower values of Corg, TN, Ni/Al, and Cu/Al. The most recent period of the CWP (~1920 CE to today) was characterized by the increased abundance warm-water taxa (N. pelagica, Cymatodiscus planetophorus, T. tenera, Plagiogramma minus, Nitzschia interruptestriata, and R. bergonii), and by the prevalence of low values of Corg, TN, Ni/Al, and Cu/Al. These changes in productivity during the LIA and CWP were likely driven by changes in solar irradiance and the migration of the Intertropical Convergence Zone. This study highlights the spatial extent of the LIA in the Eastern Tropical North Pacific and contributes to the knowledge of the productivity response to climate in tropical regions.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43297845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-10DOI: 10.1177/09596836231176490
N. K. Murray, J. L. Conroy, Kate O’Brien, E. Grimm, J. Donovan
Avian populations can substantially influence lacustrine nutrient loading and biogeochemical cycling through guano deposition. Here, we examine the influence of climate-forced avian migration throughout the Holocene on Kettle Lake, North Dakota, using stable nitrogen and carbon isotope values (δ15N, δ13C) of lake sediment organic matter. Carbon content and δ13C values are negatively correlated with δ15N and appear to be driven by changes in charcoal abundance and watershed vegetation, respectively. We find enriched δ15N values when the guano mineral struvite is present in the lake sediment core in the early to Mid-Holocene. A strong δ15N-percent Nitrogen content relationship during periods with struvite, relative to periods without struvite, indicates that guano deposition from mass bird visitations altered past nitrogen cycle processes, likely through enhanced denitrification. These results attest to the ability of waterfowl to alter lacustrine N-cycling in a mid-continental North American lake, and indicate that paleo-N data in this particular lake are recording a unique history that does not necessarily represent regional paleoenvironmental conditions. However, a significant, positive relationship between δ15N and Ambrosia and Amaranthaceae pollen abundance suggests avian visitation and its impacts on the N-cycle occurred during periods of anomalously wet summers superimposed on the background conditions of early to Mid-Holocene drought.
{"title":"Holocene relationships between climate, waterfowl, and lacustrine nutrient cycling at Kettle Lake, North Dakota, USA","authors":"N. K. Murray, J. L. Conroy, Kate O’Brien, E. Grimm, J. Donovan","doi":"10.1177/09596836231176490","DOIUrl":"https://doi.org/10.1177/09596836231176490","url":null,"abstract":"Avian populations can substantially influence lacustrine nutrient loading and biogeochemical cycling through guano deposition. Here, we examine the influence of climate-forced avian migration throughout the Holocene on Kettle Lake, North Dakota, using stable nitrogen and carbon isotope values (δ15N, δ13C) of lake sediment organic matter. Carbon content and δ13C values are negatively correlated with δ15N and appear to be driven by changes in charcoal abundance and watershed vegetation, respectively. We find enriched δ15N values when the guano mineral struvite is present in the lake sediment core in the early to Mid-Holocene. A strong δ15N-percent Nitrogen content relationship during periods with struvite, relative to periods without struvite, indicates that guano deposition from mass bird visitations altered past nitrogen cycle processes, likely through enhanced denitrification. These results attest to the ability of waterfowl to alter lacustrine N-cycling in a mid-continental North American lake, and indicate that paleo-N data in this particular lake are recording a unique history that does not necessarily represent regional paleoenvironmental conditions. However, a significant, positive relationship between δ15N and Ambrosia and Amaranthaceae pollen abundance suggests avian visitation and its impacts on the N-cycle occurred during periods of anomalously wet summers superimposed on the background conditions of early to Mid-Holocene drought.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47548445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-07DOI: 10.1177/09596836231176495
J. Sevink, T. de Haas, L. Alessandri, C. Bakels, Francesco Di Mario
The Pontine Marshes (Central Italy) are known for their long drainage history starting early in Roman times and culminating in their reclamation (bonifica integrale) by the Fascist’s regime under Mussolini, mostly in the 1930s of past century. The geology of this coastal wetland and causes for its drainage problems received limited attention till recently. We reviewed results from recent studies, identified still existing knowledge gaps and performed additional research to fill these, to produce a full description of the Holocene history and drainage of these marshes. Massive coring data that served to map the soils and surficial geology, observations in archaeological excavations, analytical data on soil and sediment characteristics, and radiocarbon datings allowed us to distinguish several phases in this history, with a main break in the early Roman Republican period with the first systematic drainage works. Earlier, natural processes brought about by sea level rise largely controlled its drainage. Once artificial drainage started, soil subsidence became an important process, aggravating the drainage problems. The bonifica introduced mechanical drainage, temporarily masking the impacts of subsidence. We quantified the historical subsidence using DTMs and developed scenarios for the impacts of sea level rise and subsidence in 2100 and 2200, assuming that this rise will be mitigated by a coastal defence system and enhanced capacity of the mechanical drainage. Our results demonstrate the important role of soil subsidence throughout the history of this wetland and need to include subsidence in scenarios for the impacts of sea level rise.
{"title":"The Pontine Marshes: An integrated study of the origin, history, and future of a famous coastal wetland in Central Italy","authors":"J. Sevink, T. de Haas, L. Alessandri, C. Bakels, Francesco Di Mario","doi":"10.1177/09596836231176495","DOIUrl":"https://doi.org/10.1177/09596836231176495","url":null,"abstract":"The Pontine Marshes (Central Italy) are known for their long drainage history starting early in Roman times and culminating in their reclamation (bonifica integrale) by the Fascist’s regime under Mussolini, mostly in the 1930s of past century. The geology of this coastal wetland and causes for its drainage problems received limited attention till recently. We reviewed results from recent studies, identified still existing knowledge gaps and performed additional research to fill these, to produce a full description of the Holocene history and drainage of these marshes. Massive coring data that served to map the soils and surficial geology, observations in archaeological excavations, analytical data on soil and sediment characteristics, and radiocarbon datings allowed us to distinguish several phases in this history, with a main break in the early Roman Republican period with the first systematic drainage works. Earlier, natural processes brought about by sea level rise largely controlled its drainage. Once artificial drainage started, soil subsidence became an important process, aggravating the drainage problems. The bonifica introduced mechanical drainage, temporarily masking the impacts of subsidence. We quantified the historical subsidence using DTMs and developed scenarios for the impacts of sea level rise and subsidence in 2100 and 2200, assuming that this rise will be mitigated by a coastal defence system and enhanced capacity of the mechanical drainage. Our results demonstrate the important role of soil subsidence throughout the history of this wetland and need to include subsidence in scenarios for the impacts of sea level rise.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43636159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-02DOI: 10.1177/09596836231176485
M. Lerch, M. Stutzriemer, M. Bliedtner, Tobias Bromm, Melissa Sehrt, Nina Feistmantl, Benjamin Dietre, W. Kofler, Morena Boysen, G. Salazar, S. Szidat, C. Geitner, Jean Nicolas Haas, D. Schäfer, B. Glaser, M. Zech
Peatlands are receiving increasing attention in palaeoenvironmental research and represent very useful terrestrial archives for reconstructing vegetation, climate and human history. Previous palaeoenvironmental studies in the Fotsch Valley, Stubai Alps, Austria, focused on geoarchaeological investigations on the Ullafelsen representing a very important prehistorical encampment site used by Mesolithic hunter-gatherers (10.9–9.5 cal. kyr BP). In order to contribute to a better understanding of the landscape evolution of the Fotsch Valley, we here studied the close-by subalpine ‘Potsdamer Hütte Mire’ by applying radiocarbon dating as well as elemental, biomarker, compound-specific stable isotope, palynological and macrofossil analyses on bulk peat samples. The calculated age-depth model using R Bacon indicates the beginning of peat formation during the Early Holocene and shows a strongly reduced peat accumulation rate (PAR) from 170 to 121 cm depth (8.5–2.1 cal. kyr BP) and/or a striking hiatus. Results of leaf wax-derived n-alkane biomarkers as well as macrofossils and palynological indicators reflect the local presence of coniferous trees and the synchronous expansion of deciduous trees during the Early Holocene. The above-mentioned strongly reduced PAR and/or hiatus coincides with the Neolithic, the Bronze and the Iron Age, and goes hand in hand with strong changes in vegetation and an increase of micro-charcoal and black carbon. Despite age uncertainties, these changes can be explained with strongly increasing human and livestock activities in form of deforestation, domestic fires and the beginning of Alpine pastoralism. The latter is confirmed by the finding of pasture and cultural indicator pollen (Cerealia-type, Rumex, Plantago lanceolata, Poaceae) occurring since the Middle to Late Bronze Age. The oxygen isotope composition of sugar biomarkers (δ18Osugars) likely reflects the dry versus humid climatic variability associated with the Holocene climatic optimum during the Mesolithic, the Roman Age, the Late Antique Little Ice Age, the Middle Ages and the Little Ice Age.
{"title":"Holocene landscape evolution, palaeoclimate and human impact in the Fotsch Valley, Stubai Alps, Austria: Interrogating biomarkers, stable isotopes, macrofossils and palynological indicators from a subalpine mire archive","authors":"M. Lerch, M. Stutzriemer, M. Bliedtner, Tobias Bromm, Melissa Sehrt, Nina Feistmantl, Benjamin Dietre, W. Kofler, Morena Boysen, G. Salazar, S. Szidat, C. Geitner, Jean Nicolas Haas, D. Schäfer, B. Glaser, M. Zech","doi":"10.1177/09596836231176485","DOIUrl":"https://doi.org/10.1177/09596836231176485","url":null,"abstract":"Peatlands are receiving increasing attention in palaeoenvironmental research and represent very useful terrestrial archives for reconstructing vegetation, climate and human history. Previous palaeoenvironmental studies in the Fotsch Valley, Stubai Alps, Austria, focused on geoarchaeological investigations on the Ullafelsen representing a very important prehistorical encampment site used by Mesolithic hunter-gatherers (10.9–9.5 cal. kyr BP). In order to contribute to a better understanding of the landscape evolution of the Fotsch Valley, we here studied the close-by subalpine ‘Potsdamer Hütte Mire’ by applying radiocarbon dating as well as elemental, biomarker, compound-specific stable isotope, palynological and macrofossil analyses on bulk peat samples. The calculated age-depth model using R Bacon indicates the beginning of peat formation during the Early Holocene and shows a strongly reduced peat accumulation rate (PAR) from 170 to 121 cm depth (8.5–2.1 cal. kyr BP) and/or a striking hiatus. Results of leaf wax-derived n-alkane biomarkers as well as macrofossils and palynological indicators reflect the local presence of coniferous trees and the synchronous expansion of deciduous trees during the Early Holocene. The above-mentioned strongly reduced PAR and/or hiatus coincides with the Neolithic, the Bronze and the Iron Age, and goes hand in hand with strong changes in vegetation and an increase of micro-charcoal and black carbon. Despite age uncertainties, these changes can be explained with strongly increasing human and livestock activities in form of deforestation, domestic fires and the beginning of Alpine pastoralism. The latter is confirmed by the finding of pasture and cultural indicator pollen (Cerealia-type, Rumex, Plantago lanceolata, Poaceae) occurring since the Middle to Late Bronze Age. The oxygen isotope composition of sugar biomarkers (δ18Osugars) likely reflects the dry versus humid climatic variability associated with the Holocene climatic optimum during the Mesolithic, the Roman Age, the Late Antique Little Ice Age, the Middle Ages and the Little Ice Age.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43748423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-02DOI: 10.1177/09596836231176501
S. Costanzo, A. Zerboni, A. Manzo
Studies upon past climates, natural landscapes, and environments of archaeologically pivotal regions of northern Africa have been of paramount interest in the past decades. For some of those regions, the human-environmental nexus, intended as the biunivocal mutual agency between people and nature, has been a long-standing research question; yet, for other areas, the environmental record is a still unexplored archive. Here we present case studies discussing archaeo-environmental sites from the easternmost stretches of the Sahelian belt, in the Kassala region of Sudan. Therein, in a landscape that is currently characterized by granitoid rocky outcrops dotting a vast gravelly pediplain colonized by xerophytes and thin ephemeral grass, pedosedimentary features that encase the climatic history of the region are found. By means of field survey, physico-chemical laboratory analyses, micromorphological analyses, and radiometric dating, we investigated the uppermost portion of the Quaternary record to contextualize the Late-Holocene archaeological record. The main identified features include buried isohumic soil horizons in lower flat grounds, which are legacy of water-reliant prairie environments formed in the wetter Early to Middle Holocene, and later accretional dusty aeolian deposits intermingled with colluvial gravels close to the outcrops’ eroded foothills, testimony of a climatic deterioration towards aridity and erosion driven by hyper seasonality. Results are of great importance as a contribution to a more holistic understanding of past human economies of the region, as well as being a newly added tile to the reconstruction of surface processes dynamics over Africa and their response to global climate changes.
{"title":"Holocene geomorphological and pedosedimentary archives of eastern Sahelian paleoenvironments (Kassala, Sudan)","authors":"S. Costanzo, A. Zerboni, A. Manzo","doi":"10.1177/09596836231176501","DOIUrl":"https://doi.org/10.1177/09596836231176501","url":null,"abstract":"Studies upon past climates, natural landscapes, and environments of archaeologically pivotal regions of northern Africa have been of paramount interest in the past decades. For some of those regions, the human-environmental nexus, intended as the biunivocal mutual agency between people and nature, has been a long-standing research question; yet, for other areas, the environmental record is a still unexplored archive. Here we present case studies discussing archaeo-environmental sites from the easternmost stretches of the Sahelian belt, in the Kassala region of Sudan. Therein, in a landscape that is currently characterized by granitoid rocky outcrops dotting a vast gravelly pediplain colonized by xerophytes and thin ephemeral grass, pedosedimentary features that encase the climatic history of the region are found. By means of field survey, physico-chemical laboratory analyses, micromorphological analyses, and radiometric dating, we investigated the uppermost portion of the Quaternary record to contextualize the Late-Holocene archaeological record. The main identified features include buried isohumic soil horizons in lower flat grounds, which are legacy of water-reliant prairie environments formed in the wetter Early to Middle Holocene, and later accretional dusty aeolian deposits intermingled with colluvial gravels close to the outcrops’ eroded foothills, testimony of a climatic deterioration towards aridity and erosion driven by hyper seasonality. Results are of great importance as a contribution to a more holistic understanding of past human economies of the region, as well as being a newly added tile to the reconstruction of surface processes dynamics over Africa and their response to global climate changes.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41781695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-02DOI: 10.1177/09596836231176492
M. Ghilardi, J. Revelles, Jean-Baptiste Mary, F. Rita, Claire Delhon, Doriane Delanghe¹, Sébastien Robresco
Two coastal areas located on the North-Western side of Corsica Island have been investigated to reconstruct their Mid- to Late-Holocene landscape evolution together with the history of human occupation. Particular attention has been paid to the study of shoreline migration and vegetation history alongside land-use. Three boreholes were drilled to a maximum depth of 4.20 m and laboratory work comprised the identification of molluscs and pollen/NPPs as well as sedimentological analyses. Chronostratigraphy is based on a series of 18 radiocarbon datings and enabled to reconstruct the environments in the Fangu Estuary to the north of the World Heritage site over the last six millennia, and over the last four millennia on the Girolata coastal plain to the south. Palaeogeographic reconstruction of shoreline mobility is established for each site based on borehole chronostratigraphy analysis. In addition, two original pollen and NPPs diagrams have been established for the Girolata and Fangu sites. These reveal that anthropogenic activities began to significantly impact local vegetation cover ca. 2500 years BP at Girolata, and ca. 2000 years BP at Fangu. Of particular interest, our work records the first complete pollen sequence in Corsica for Roman times at Girolata: first, the exploitation of cereals, grapevines and the development of husbandry is observed during the Roman Republic (500 BCE–0), followed by the almost exclusive cultivation of Olea sp. during the Roman Empire (0–500 CE). Following this, and using other regional pollen studies obtained for NW Corsica, we propose a regional evolution of the complex human-environment interactions for the last six millennia. Our results reveal a peak of regional forest decline (the most intense event recorded for the Late-Holocene) from the 11th to the 16th centuries CE which can be attributed to the exploitation of wood resources during the Pisan and Genoese dominations of the island.
{"title":"Mid- to Late-Holocene coastal morphological evolution, vegetation history and land-use changes of the Porto Gulf UNESCO World Heritage site and its surroundings (NW Corsica Island, Western Mediterranean)","authors":"M. Ghilardi, J. Revelles, Jean-Baptiste Mary, F. Rita, Claire Delhon, Doriane Delanghe¹, Sébastien Robresco","doi":"10.1177/09596836231176492","DOIUrl":"https://doi.org/10.1177/09596836231176492","url":null,"abstract":"Two coastal areas located on the North-Western side of Corsica Island have been investigated to reconstruct their Mid- to Late-Holocene landscape evolution together with the history of human occupation. Particular attention has been paid to the study of shoreline migration and vegetation history alongside land-use. Three boreholes were drilled to a maximum depth of 4.20 m and laboratory work comprised the identification of molluscs and pollen/NPPs as well as sedimentological analyses. Chronostratigraphy is based on a series of 18 radiocarbon datings and enabled to reconstruct the environments in the Fangu Estuary to the north of the World Heritage site over the last six millennia, and over the last four millennia on the Girolata coastal plain to the south. Palaeogeographic reconstruction of shoreline mobility is established for each site based on borehole chronostratigraphy analysis. In addition, two original pollen and NPPs diagrams have been established for the Girolata and Fangu sites. These reveal that anthropogenic activities began to significantly impact local vegetation cover ca. 2500 years BP at Girolata, and ca. 2000 years BP at Fangu. Of particular interest, our work records the first complete pollen sequence in Corsica for Roman times at Girolata: first, the exploitation of cereals, grapevines and the development of husbandry is observed during the Roman Republic (500 BCE–0), followed by the almost exclusive cultivation of Olea sp. during the Roman Empire (0–500 CE). Following this, and using other regional pollen studies obtained for NW Corsica, we propose a regional evolution of the complex human-environment interactions for the last six millennia. Our results reveal a peak of regional forest decline (the most intense event recorded for the Late-Holocene) from the 11th to the 16th centuries CE which can be attributed to the exploitation of wood resources during the Pisan and Genoese dominations of the island.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46802198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-02DOI: 10.1177/09596836231176487
H. D. Lorenzo, V. Di Donato, F. Molisso, C. Lubritto, E. Russo Ermolli
Pollen analysis of a marine core collected in the Gulf of S. Eufemia (Tyrrhenian Calabria, Italy) allowed reconstructing the regional changes in vegetation and land use over the last 5000 years. Pollen diagram zonation through Constrained Cluster Analysis highlighted three compositional zones whose boundaries mark the major changes that affected the vegetation structure. A dense forest cover with a few signs of human activities characterized the wide pollen source area from 5055 to 2700 BP (Zone 1). In this period, the Pre-Protohistoric communities were mainly concentrated on the Tropea Promontory where they had a significant local impact. Minor forest rarefactions at 5000–4800 BP, ca. 4400–4000 BP, ca. 3450–3150 BP were correlated to phases of climatic shifts toward aridity. From 2700 to 2000 BP (Zone 2a), a longer and more incisive period of forest decline was connected to a time of aridity that favored the intense activities of an increasing anthropogenic pressure. Indeed, important urban centers developed in the area during the Greek and Roman colonization. Diffuse deforestation and cultivation occurred from 790 BP (Zone 3), enhancing soil erosion and fluvial discharge as testified by the sudden increase in sedimentation rates. This disruption of the slope morphodynamics was connected to the collapse of territorial management following the end of the Western Roman Empire. Compositional Data Analysis, applied to a simplified pollen dataset, highlighted both a negative correlation between Abies and Fagus and a close similarity between the AP/NAP curve and the Axis 1 scores of the Relative Variation Biplot.
{"title":"A high-resolution record of landscape changes and land use over the last 5000 years in western Calabria (S. Eufemia Gulf, southern Tyrrhenian Sea, Italy)","authors":"H. D. Lorenzo, V. Di Donato, F. Molisso, C. Lubritto, E. Russo Ermolli","doi":"10.1177/09596836231176487","DOIUrl":"https://doi.org/10.1177/09596836231176487","url":null,"abstract":"Pollen analysis of a marine core collected in the Gulf of S. Eufemia (Tyrrhenian Calabria, Italy) allowed reconstructing the regional changes in vegetation and land use over the last 5000 years. Pollen diagram zonation through Constrained Cluster Analysis highlighted three compositional zones whose boundaries mark the major changes that affected the vegetation structure. A dense forest cover with a few signs of human activities characterized the wide pollen source area from 5055 to 2700 BP (Zone 1). In this period, the Pre-Protohistoric communities were mainly concentrated on the Tropea Promontory where they had a significant local impact. Minor forest rarefactions at 5000–4800 BP, ca. 4400–4000 BP, ca. 3450–3150 BP were correlated to phases of climatic shifts toward aridity. From 2700 to 2000 BP (Zone 2a), a longer and more incisive period of forest decline was connected to a time of aridity that favored the intense activities of an increasing anthropogenic pressure. Indeed, important urban centers developed in the area during the Greek and Roman colonization. Diffuse deforestation and cultivation occurred from 790 BP (Zone 3), enhancing soil erosion and fluvial discharge as testified by the sudden increase in sedimentation rates. This disruption of the slope morphodynamics was connected to the collapse of territorial management following the end of the Western Roman Empire. Compositional Data Analysis, applied to a simplified pollen dataset, highlighted both a negative correlation between Abies and Fagus and a close similarity between the AP/NAP curve and the Axis 1 scores of the Relative Variation Biplot.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49653565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-28DOI: 10.1177/09596836231176489
V. Kolka, D. Tolstobrov, G. D. Corner, O. Korsakova, Alena Tolstobrova, A. Vashkov
The paper presents isolation basin stratigraphy in bottom sediments from nine lakes in the Teriberka area on the Kola Peninsula, northwestern Russia. Isolation contacts in these basins, identified from lithological and diatom analysis, were used together with 25 radiocarbon dates, to construct a relative sea-level (RSL) curve for the Holocene. Records of marine water re-influx were found in the sediment sequence from one lake, located at c. 17 m a.s.l. The re-influx of marine water seems to be caused by the mid-Holocene (Tapes) transgression and tsunami event. The RSL curve indicates several phases in the postglacial evolution of the Kola coast. An early phase of rapid sea-level fall of c. 32 m around 11,500 cal yr BP, at a rate of c. 40 mm per year, corresponds to glacio-isostatically induced emergence following deglaciation at the Younger Dryas and beginning of the Holocene. In the time interval between c. 11,000 and 7600 cal yr BP, either a stillstand or a slight rise in relative sea level, cresting at about 21 m a.s.l., is suggested in the Teriberka area. This is followed, after c. 7300 cal yr BP to the present day, by a slow glacioisostatic emergence with an average rate of about 2–3 mm per year.
本文介绍了俄罗斯西北部科拉半岛Teriberka地区九个湖泊底部沉积物的孤立盆地地层学。通过岩性和硅藻分析确定的这些盆地中的隔离接触，与25个放射性碳年代一起使用，构建了全新世的相对海平面（RSL）曲线。在一个湖泊的沉积物序列中发现了海水重新流入的记录，该湖泊位于约17年 海水的再次涌入似乎是由全新世中期（Tapes）海侵和海啸事件引起的。RSL曲线表明了科拉海岸冰川后演化的几个阶段。11500年左右海平面迅速下降约32米的早期阶段 cal yr BP，以每年约40毫米的速度，对应于年轻Dryas冰川消退和全新世开始后冰川均衡引起的出现。在约11000至7600 cal yr BP之间的时间间隔内，相对海平面出现静止或轻微上升，最高点约为21 m a.s.l.，建议在Teriberka地区。随后，在公元7300年BP之后，直到今天，缓慢的冰川均衡出现，平均速度约为2-3 毫米/年。
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Pub Date : 2023-05-17DOI: 10.1177/09596836231169989
E. Iriarte, J. Revelles, W. Finsinger, F. Mesquita‐Joanes, M. A. Rodrigo, F. Burjachs, I. Expósito, J. Martí Molist, L. Planagumà, G. Alcalde, M. Saña
Volcanic eruptions are key drivers of climate variability, with complex environmental consequences at regional and local scales that are rarely documented in high-resolution sedimentary records. In this work we present the results of a 15 m long paleolake core (Pla de les Preses core, Vall d’en Bas, Girona, NE Spain) covering the Late Pleistocene-Holocene transition. Multiproxy analyses including chronostratigraphy, sedimentology, micropalaeontology and geochemistry are used to reconstruct the paleoenvironmental framework of the Late Pleistocene-Holocene transition and to detect the youngest Holocene volcanic eruptions in the Garrotxa Volcanic Field (GVF) and the Iberian Peninsula. The studied sedimentary record covers the last ca. 13.5 ka cal BP and was punctuated by several rapid climatic changes including the 9.3, 8.2 and 7.1 ka events, affecting the hydrological evolution of a barrier-lake formed due to the volcanic damming of the Fluvià river. Sedimentological and geochemical analyses unveil the environmental history of Vall d’en Bas valley; the formation of a lacustrine area within a fluvial environment around 13.5 ka cal BP and later a wetland phase between 9.3 and 8.2 ka cal BP. Abrupt sedimentary changes marking the onset and demise of the wetland phase were linked to hemispheric cooling and drying events (e.g. 9.3 and 8.2 ka cal BP), provoking a decline in the water table during these phases. In addition, 30 tephra layers are detected thorough the core, showing previously unknown intense volcanic activity from 13.5 to 8.3 ka cal BP in the GVF. In that sense, the Pla de les Preses sequence provides, for the first time, evidence for early Holocene volcanic activity in NE Iberia that should be taken into account in future tephra studies in the western Mediterranean realm.
火山爆发是气候变化的关键驱动因素，在区域和地方尺度上具有复杂的环境后果，高分辨率沉积记录中很少记录这些后果。在这项工作中，我们提出了一个15 m长的古湖岩芯（Pla de les Preses岩芯，Vall d‘en Bas，Girona，NE Spain），覆盖晚更新世-全新世过渡。包括时间地层学、沉积学、微体层学和地球化学在内的多重分析被用于重建晚更新世-全新世过渡的古环境框架，并探测加洛特萨火山场（GVF）和伊比利亚半岛最年轻的全新世火山爆发。所研究的沉积记录涵盖了最后一个约。13.5 ka cal BP，并被几次快速的气候变化打断，包括9.3、8.2和7.1 ka事件，影响了Fluvià河火山筑坝形成的堰塞湖的水文演变。沉积学和地球化学分析揭示了巴思河谷的环境历史；13.5年左右在河流环境中形成的湖泊区 ka cal BP和随后9.3至8.2之间的湿地阶段 ka cal BP。标志着湿地阶段开始和结束的突然沉积变化与半球冷却和干燥事件有关（例如9.3和8.2 ka cal BP），在这些阶段引起地下水位下降。此外，在岩芯中探测到30个火山灰层，显示出之前未知的13.5至8.3的强烈火山活动 ka cal BP在GVF中。从这个意义上说，Pla de les Preses序列首次为伊比利亚东北部全新世早期火山活动提供了证据，在未来地中海西部地区的火山活动研究中应将其考虑在内。
{"title":"Youngest Iberian Holocene volcanic eruptions and paleoenvironmental evolution of a barrier-paleolake in the Garrotxa Volcanic Field (NE Spain)","authors":"E. Iriarte, J. Revelles, W. Finsinger, F. Mesquita‐Joanes, M. A. Rodrigo, F. Burjachs, I. Expósito, J. Martí Molist, L. Planagumà, G. Alcalde, M. Saña","doi":"10.1177/09596836231169989","DOIUrl":"https://doi.org/10.1177/09596836231169989","url":null,"abstract":"Volcanic eruptions are key drivers of climate variability, with complex environmental consequences at regional and local scales that are rarely documented in high-resolution sedimentary records. In this work we present the results of a 15 m long paleolake core (Pla de les Preses core, Vall d’en Bas, Girona, NE Spain) covering the Late Pleistocene-Holocene transition. Multiproxy analyses including chronostratigraphy, sedimentology, micropalaeontology and geochemistry are used to reconstruct the paleoenvironmental framework of the Late Pleistocene-Holocene transition and to detect the youngest Holocene volcanic eruptions in the Garrotxa Volcanic Field (GVF) and the Iberian Peninsula. The studied sedimentary record covers the last ca. 13.5 ka cal BP and was punctuated by several rapid climatic changes including the 9.3, 8.2 and 7.1 ka events, affecting the hydrological evolution of a barrier-lake formed due to the volcanic damming of the Fluvià river. Sedimentological and geochemical analyses unveil the environmental history of Vall d’en Bas valley; the formation of a lacustrine area within a fluvial environment around 13.5 ka cal BP and later a wetland phase between 9.3 and 8.2 ka cal BP. Abrupt sedimentary changes marking the onset and demise of the wetland phase were linked to hemispheric cooling and drying events (e.g. 9.3 and 8.2 ka cal BP), provoking a decline in the water table during these phases. In addition, 30 tephra layers are detected thorough the core, showing previously unknown intense volcanic activity from 13.5 to 8.3 ka cal BP in the GVF. In that sense, the Pla de les Preses sequence provides, for the first time, evidence for early Holocene volcanic activity in NE Iberia that should be taken into account in future tephra studies in the western Mediterranean realm.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43023437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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