Pub Date : 2023-07-29DOI: 10.1177/09596836231185831
Caterina Kozanoglou, M. Triantaphyllou, M. Geraga, G. Rousakis, G. Papatheodorou, A. Arabas, M. Dimiza, A. Gogou
High-resolution data for planktonic foraminifera and their groups of ecological interest, including Herbivores and Carnivores, combined with benthic foraminifera and a great variety of biogeochemical indices from the SE Aegean sediment core ST5, contribute to a detailed study concerning major and minor climatic episodes during Holocene. The ST5 sediment record, retrieved from the Tilos-Symi marine basin, evidences the impact of the nearby land, the local climate, and the Rhodes Gyre imprint on the eastern Mediterranean water circulation. Pronounced environmental changes are detected during a preconditioning period of ~400 years before the onset of sapropel S1 deposition and during the deposition phases S1a (10.0–8.4 ka BP) and S1b (8.0–6.1 ka BP). Major freshwater influx episodes (10.5 ka BP, 9.2–8.9 ka BP, 7.4 ka BP, 4.5–4.3 ka BP, and few additional during the Late-Holocene) are revealed, prominent oxygen deficiency time intervals (including a distinct brief anoxic period) as well as several drier, cooler and warmer climatic events. Herbivore planktonic foraminifera alternate their dominance with the Carnivores at the preconditioning period before the S1 onset and at the Late-Holocene (2.0–1.5 ka BP) when conditions of good seawater circulation, oxygenation, and productivity alternate with stratified low oxygenation waters and high freshwater influx from the land.
浮游有孔虫及其具有生态意义的群体（包括草食动物和食肉动物）的高分辨率数据，结合海底有孔虫和爱琴海东南部沉积物核心ST5的各种生物地球化学指数，有助于对全新世主要和次要气候事件进行详细研究。从Tilos-Symi海洋盆地检索到的ST5沉积物记录证明了附近土地、当地气候和罗德斯-吉尔印记对东地中海水循环的影响。在约400的预处理期内检测到明显的环境变化 腐泥S1沉积开始前和沉积阶段S1a（10.0–8.4 ka BP）和S1b（8.0–6.1 ka BP）。主要淡水流入事件（10.5 ka BP，9.2–8.9 ka BP，7.4 ka BP，4.5–4.3 ka BP，以及全新世晚期的少量额外事件）、显著的缺氧时间间隔（包括明显的短暂缺氧期）以及几个更干燥、更凉爽和更温暖的气候事件。在S1爆发前的预处理期和全新世晚期（2.0–1.5 ka BP），当良好的海水循环、充氧和生产力条件与分层的低充氧水和来自陆地的高淡水流入交替时。
{"title":"A high-resolution study of planktonic foraminifera during the Holocene at the Tilos-Symi sea basin in the SE Aegean Sea","authors":"Caterina Kozanoglou, M. Triantaphyllou, M. Geraga, G. Rousakis, G. Papatheodorou, A. Arabas, M. Dimiza, A. Gogou","doi":"10.1177/09596836231185831","DOIUrl":"https://doi.org/10.1177/09596836231185831","url":null,"abstract":"High-resolution data for planktonic foraminifera and their groups of ecological interest, including Herbivores and Carnivores, combined with benthic foraminifera and a great variety of biogeochemical indices from the SE Aegean sediment core ST5, contribute to a detailed study concerning major and minor climatic episodes during Holocene. The ST5 sediment record, retrieved from the Tilos-Symi marine basin, evidences the impact of the nearby land, the local climate, and the Rhodes Gyre imprint on the eastern Mediterranean water circulation. Pronounced environmental changes are detected during a preconditioning period of ~400 years before the onset of sapropel S1 deposition and during the deposition phases S1a (10.0–8.4 ka BP) and S1b (8.0–6.1 ka BP). Major freshwater influx episodes (10.5 ka BP, 9.2–8.9 ka BP, 7.4 ka BP, 4.5–4.3 ka BP, and few additional during the Late-Holocene) are revealed, prominent oxygen deficiency time intervals (including a distinct brief anoxic period) as well as several drier, cooler and warmer climatic events. Herbivore planktonic foraminifera alternate their dominance with the Carnivores at the preconditioning period before the S1 onset and at the Late-Holocene (2.0–1.5 ka BP) when conditions of good seawater circulation, oxygenation, and productivity alternate with stratified low oxygenation waters and high freshwater influx from the land.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42106041","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 : 2023-07-22DOI: 10.1177/09596836231185835
Rubén Pardo Martínez, José Antonio Olmedo Cobo, J. G. Zotano, F. A. Sánchez
The mountains of the southern Iberian Peninsula are important biodiversity hotspots. They are also home to several relict species that are threatened with extinction in the face of global change. One of the best examples is the Serranía de Ronda, a system of mountainous reliefs located at the western end of the Baetic Cordillera. Its tree cover includes, among other unusual taxa, endemic formations such as the Spanish fir ( Abies pinsapo) and Portuguese oak ( Quercus faginea) forests. However, despite the ecological exceptionality of this mountainous area, little is known about its paleobiogeography. To remedy this, in this research we take a multidisciplinary approach based on the application of several different paleoecological disciplines, of which pedoanthracology is the main methodological tool. Six new soil surveys were performed, which were added to the existing pedoanthracological network, making a total of 43 soil sampling sites. The taxonomic analysis revealed several taxa, such as Abies, Fraxinus, Pinus and Pinus sylvestris-type, which are currently absent in several of the sampled sites. After contextualizing the 36 new radiocarbon dates obtained, the results confirm the antiquity of certain paleoendemic forests in the Serranía de Ronda, and the important role played by certain mountain enclaves as refuges for conifers such as A. pinsapo and Pinus sylvestris-type during the Pleistocene-Holocene transition. The dissemination of the results of this research will enable them to be implemented in the different strategies of adaptive management of the most threatened forests of the Serranía de Ronda.
伊比利亚半岛南部的山脉是重要的生物多样性热点地区。面对全球变化，它们也是几个濒临灭绝的物种的家园。其中一个最好的例子是Serranía de Ronda，这是一个位于Baetic Cordillera西端的山地浮雕系统。在其他不寻常的分类群中，它的树木覆盖包括西班牙冷杉(Abies pinsapo)和葡萄牙橡树(Quercus faginea)等特有的结构。然而，尽管这一山区具有独特的生态特征，但人们对其古生物地理知之甚少。为了解决这一问题，在本研究中，我们采用了基于几种不同古生态学科应用的多学科方法，其中土壤人类学是主要的方法工具。进行了6次新的土壤调查，并将其添加到现有的土壤人类学网络中，使土壤采样点总数达到43个。分类学分析显示，冷杉(Abies)、曲松(Fraxinus)、松(Pinus)和西尔山松(Pinus sylvestris-type)等几种类群在若干样地均未出现。结合36个新的放射性碳年代，结果证实了Serranía de Ronda地区某些古特有森林的古老，以及某些山地飞地在更新世-全新世过渡时期作为针叶树(如A. pinsapo和Pinus sylvestris-type)的避难所发挥的重要作用。这项研究结果的传播将使它们能够在对Serranía de Ronda最受威胁的森林进行适应性管理的不同战略中得到执行。
{"title":"Multiproxy analysis for the paleobiogeographical reconstruction of the relict forests of the Serranía de Ronda during the Holocene (Baetic System, Spain)","authors":"Rubén Pardo Martínez, José Antonio Olmedo Cobo, J. G. Zotano, F. A. Sánchez","doi":"10.1177/09596836231185835","DOIUrl":"https://doi.org/10.1177/09596836231185835","url":null,"abstract":"The mountains of the southern Iberian Peninsula are important biodiversity hotspots. They are also home to several relict species that are threatened with extinction in the face of global change. One of the best examples is the Serranía de Ronda, a system of mountainous reliefs located at the western end of the Baetic Cordillera. Its tree cover includes, among other unusual taxa, endemic formations such as the Spanish fir ( Abies pinsapo) and Portuguese oak ( Quercus faginea) forests. However, despite the ecological exceptionality of this mountainous area, little is known about its paleobiogeography. To remedy this, in this research we take a multidisciplinary approach based on the application of several different paleoecological disciplines, of which pedoanthracology is the main methodological tool. Six new soil surveys were performed, which were added to the existing pedoanthracological network, making a total of 43 soil sampling sites. The taxonomic analysis revealed several taxa, such as Abies, Fraxinus, Pinus and Pinus sylvestris-type, which are currently absent in several of the sampled sites. After contextualizing the 36 new radiocarbon dates obtained, the results confirm the antiquity of certain paleoendemic forests in the Serranía de Ronda, and the important role played by certain mountain enclaves as refuges for conifers such as A. pinsapo and Pinus sylvestris-type during the Pleistocene-Holocene transition. The dissemination of the results of this research will enable them to be implemented in the different strategies of adaptive management of the most threatened forests of the Serranía de Ronda.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41465421","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 : 2023-07-21DOI: 10.1177/09596836231183067
A. Farooqui, Salman Khan, R. Agnihotri, B. Phartiyal, S. Shukla
The Ganga-Sai River Interfluve contains several ox-bow lakes in the fertile Central Ganga plains (CGP). A ~2.20-meter deep sedimentary profile obtained near the Chandra Shekhar Azad bird sanctuary (Nawabganj lake-NL) of the CGP was studied to understand the evolution of the ecosystem and climate using pollen/spores, diatoms, testate amoebae, environmental magnetic data,and carbon and nitrogen isotopes. This sedimentary profile is chronologically well-constrained by five radiocarbon (14C) dates. Between 4.6 and 4.4 ka, the sandy sediment and pollen evidence for riparian forest, the absence of aquatic pollen and sponge spicules suggest scant water in the vicinity through the river channel. A semi-closed fluvial ecosystem between 4.4 and 4.2 ka is indicated by testate amoebae, sponge spicules and arboreal pollen. At least two intermittent warm conditions prevailed between 4.6 and 4.2 ka. Between 4.2 and 2.8 ka, high aquatic pollen, diatoms and testate amoebae indicate a lake ecosystem. By ~2.8–0.9 ka the gammoscleres from sponges formed during dry seasons indicate recharging during monsoon as the river shifted. Thereafter, agricultural pollen (Brassica and Apiaceae) indicates a further shift in the lake boundary exposing land. The highly sandy texture, fluctuating δ13C, δ15N and magnetic mineral values indicate an unstable fluvio-lacustrine deposition inducing hydroecological changes influenced by intermittent about 5–6 humid and dry climatic conditions since ~4.6 ka to present. The calcrete layer in the bottom sediments shows high aridity in CGP between ~5 and 4.6 ka reaching the climax cold-dry event of ~4.2 ka recorded worldwide. The spectral analysis of palynological data from NL and the contemporary Barela Lake, reveals de Vries and Gleissberg cycles of low and high solar irradiance at centennial to multi-centennial scale during the Holocene. The impact on vegetation, sediment depositional dynamics, and shift in river channel was more rapid showing the dominance of ~200 years. periodicity post ~5 ka as compared to ~300 years of dominance prior to this. This centennial timescale is of great speculation for future climate predictions in CGP coupled with the anthropogenic forcings.
{"title":"Monitoring hydroecology and climatic variability since ~4.6 ka from palynological, sedimentological and environmental perspectives in an Ox-bow lake, Central Ganga Plain, India","authors":"A. Farooqui, Salman Khan, R. Agnihotri, B. Phartiyal, S. Shukla","doi":"10.1177/09596836231183067","DOIUrl":"https://doi.org/10.1177/09596836231183067","url":null,"abstract":"The Ganga-Sai River Interfluve contains several ox-bow lakes in the fertile Central Ganga plains (CGP). A ~2.20-meter deep sedimentary profile obtained near the Chandra Shekhar Azad bird sanctuary (Nawabganj lake-NL) of the CGP was studied to understand the evolution of the ecosystem and climate using pollen/spores, diatoms, testate amoebae, environmental magnetic data,and carbon and nitrogen isotopes. This sedimentary profile is chronologically well-constrained by five radiocarbon (14C) dates. Between 4.6 and 4.4 ka, the sandy sediment and pollen evidence for riparian forest, the absence of aquatic pollen and sponge spicules suggest scant water in the vicinity through the river channel. A semi-closed fluvial ecosystem between 4.4 and 4.2 ka is indicated by testate amoebae, sponge spicules and arboreal pollen. At least two intermittent warm conditions prevailed between 4.6 and 4.2 ka. Between 4.2 and 2.8 ka, high aquatic pollen, diatoms and testate amoebae indicate a lake ecosystem. By ~2.8–0.9 ka the gammoscleres from sponges formed during dry seasons indicate recharging during monsoon as the river shifted. Thereafter, agricultural pollen (Brassica and Apiaceae) indicates a further shift in the lake boundary exposing land. The highly sandy texture, fluctuating δ13C, δ15N and magnetic mineral values indicate an unstable fluvio-lacustrine deposition inducing hydroecological changes influenced by intermittent about 5–6 humid and dry climatic conditions since ~4.6 ka to present. The calcrete layer in the bottom sediments shows high aridity in CGP between ~5 and 4.6 ka reaching the climax cold-dry event of ~4.2 ka recorded worldwide. The spectral analysis of palynological data from NL and the contemporary Barela Lake, reveals de Vries and Gleissberg cycles of low and high solar irradiance at centennial to multi-centennial scale during the Holocene. The impact on vegetation, sediment depositional dynamics, and shift in river channel was more rapid showing the dominance of ~200 years. periodicity post ~5 ka as compared to ~300 years of dominance prior to this. This centennial timescale is of great speculation for future climate predictions in CGP coupled with the anthropogenic forcings.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49221896","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 : 2023-07-17DOI: 10.1177/09596836231185837
Xun Yang, F. Becker, Moritz Nykamp, B. Ludwig, M. Doğan, B. Schütt
The Pergamon micro-region (western Türkiye) has experienced several phases of increased geomorphodynamics during the Holocene. However, the role of local–regional human activities during a transformation between Hellenism and the Roman Imperial period and supra-regional climate fluctuations is still under discussion. Five sediment profiles from the alluvial fan of the rural Deliktaş catchment are analyzed and radiocarbon-dated to provide a sedimentological record covering the Holocene. Our results indicate seven phases of changing sediment dynamics. Five Holocene cycles of coarse- and fine-textured fan sediment deposition covered the paleochannel deposits of the Çaylak creek, and the floodplain sediments of the receiving Geyikli river which aggraded toward the piedmont during the Mid-Holocene. The landscape became stable on the Deliktaş fan and Geyikli floodplain at least ca. 4–3.4 cal ka BP as indicated by paleosols. These paleosols were again buried by fan sediments marking the first phase of accelerated geomorphodynamics during the Late Holocene. Both the local onset of human activities and the regional Mid-Holocene aridization with rapid climate changes play a role. The increased number of archeological sites and high human pressure on the environment during the Hellenistic–Roman transformation in the Deliktaş area and Pergamon micro-region were hypothesized to contribute to a phase of increased geomorphodynamic activity during the last 2.5 ka. This, however, is less apparent in our record. Our study emphasizes the importance of both, the climatic system and rural-urban cultural history, on landscape development, suggesting potential responses of locally diverse geomorphodynamics on regional-scale transformation in the eastern Mediterranean.
佩加蒙微区(西基耶岛)在全新世经历了几个增强的地貌动力学阶段。然而，在希腊化和罗马帝国时期之间的转变过程中，地方-区域人类活动与超区域气候波动的作用仍在讨论中。本文对deliktai流域冲积扇的5个沉积物剖面进行了分析，并进行了放射性碳定年，以提供覆盖全新世的沉积学记录。我们的研究结果显示了泥沙动力学变化的七个阶段。全新世5个旋回的粗粒和细粒扇状沉积覆盖了Çaylak溪的古河道沉积和中全新世向山前淤积的接收格伊克利河洪泛平原沉积。古土壤表明，德利克塔伊扇和格伊克利洪泛平原的景观至少在约4 ~ 3.4 cal ka BP左右稳定下来。这些古土壤再次被扇状沉积物掩埋，标志着晚全新世加速地貌动力学的第一阶段。人类活动的局部发生和气候快速变化的区域中全新世干旱化都发挥了作用。据推测，德利克塔伊地区和佩加蒙微区在希腊-罗马转变期间考古遗址数量的增加和人类对环境的高压力导致了过去2.5 ka期间地貌动力学活动的增加。然而，这一点在我们的记录中不太明显。我们的研究强调了气候系统和城乡文化历史对景观发展的重要性，并提出了地中海东部地区不同的地貌动力学对区域尺度变化的潜在响应。
{"title":"Holocene geomorphodynamics of a rural catchment in the Pergamon micro-region (eastern Mediterranean)","authors":"Xun Yang, F. Becker, Moritz Nykamp, B. Ludwig, M. Doğan, B. Schütt","doi":"10.1177/09596836231185837","DOIUrl":"https://doi.org/10.1177/09596836231185837","url":null,"abstract":"The Pergamon micro-region (western Türkiye) has experienced several phases of increased geomorphodynamics during the Holocene. However, the role of local–regional human activities during a transformation between Hellenism and the Roman Imperial period and supra-regional climate fluctuations is still under discussion. Five sediment profiles from the alluvial fan of the rural Deliktaş catchment are analyzed and radiocarbon-dated to provide a sedimentological record covering the Holocene. Our results indicate seven phases of changing sediment dynamics. Five Holocene cycles of coarse- and fine-textured fan sediment deposition covered the paleochannel deposits of the Çaylak creek, and the floodplain sediments of the receiving Geyikli river which aggraded toward the piedmont during the Mid-Holocene. The landscape became stable on the Deliktaş fan and Geyikli floodplain at least ca. 4–3.4 cal ka BP as indicated by paleosols. These paleosols were again buried by fan sediments marking the first phase of accelerated geomorphodynamics during the Late Holocene. Both the local onset of human activities and the regional Mid-Holocene aridization with rapid climate changes play a role. The increased number of archeological sites and high human pressure on the environment during the Hellenistic–Roman transformation in the Deliktaş area and Pergamon micro-region were hypothesized to contribute to a phase of increased geomorphodynamic activity during the last 2.5 ka. This, however, is less apparent in our record. Our study emphasizes the importance of both, the climatic system and rural-urban cultural history, on landscape development, suggesting potential responses of locally diverse geomorphodynamics on regional-scale transformation in the eastern Mediterranean.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45735600","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 : 2023-07-16DOI: 10.1177/09596836231183110
S. Managave, Yongsong Huang, J. Sutra, K. Anupama, S. Prasad
Paleoclimate investigations of the peat deposits in the Nilgiri Plateau, an important paleoclimate archive of India, are mainly restricted to the carbon isotope composition ((δ13C) of plant-derived materials and pollen studies. However, it is unclear whether these proxies reflect past variability in temperature or hydrology. Here, we report the hydrogen and carbon isotopic variability of n-alkanoic acid of chain length 28 (δDC28 and δ13CC28, respectively) and demonstrate that the peatland leaf wax hydrogen isotopes provide a sensitive record of past hydrology. The decoupling of δ13CC28 and δD of vegetation-corrected rain during the Holocene indicate that δD of the leaf wax compounds mainly respond to past hydrological variability whereas δ13C variations might reflect the temperature-controlled variability of C3 and C4 vegetation. Conforming with the other paleoclimate records from the region, the δDC28 variations showed a reducing precipitation trend since the early Holocene. However, a large amplitude of reconstructed δD of rain (~44‰) during the Holocene indicated changes in the moisture source and trajectory could be an additional factor contributing to the orbital-scale δD variability of proxies from the Indian region.
{"title":"Holocene precipitation hydrogen isotopic values on Nilgiri Plateau (southern India) suggest a combined effect of precipitation amount and transport paths","authors":"S. Managave, Yongsong Huang, J. Sutra, K. Anupama, S. Prasad","doi":"10.1177/09596836231183110","DOIUrl":"https://doi.org/10.1177/09596836231183110","url":null,"abstract":"Paleoclimate investigations of the peat deposits in the Nilgiri Plateau, an important paleoclimate archive of India, are mainly restricted to the carbon isotope composition ((δ13C) of plant-derived materials and pollen studies. However, it is unclear whether these proxies reflect past variability in temperature or hydrology. Here, we report the hydrogen and carbon isotopic variability of n-alkanoic acid of chain length 28 (δDC28 and δ13CC28, respectively) and demonstrate that the peatland leaf wax hydrogen isotopes provide a sensitive record of past hydrology. The decoupling of δ13CC28 and δD of vegetation-corrected rain during the Holocene indicate that δD of the leaf wax compounds mainly respond to past hydrological variability whereas δ13C variations might reflect the temperature-controlled variability of C3 and C4 vegetation. Conforming with the other paleoclimate records from the region, the δDC28 variations showed a reducing precipitation trend since the early Holocene. However, a large amplitude of reconstructed δD of rain (~44‰) during the Holocene indicated changes in the moisture source and trajectory could be an additional factor contributing to the orbital-scale δD variability of proxies from the Indian region.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43305810","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 : 2023-07-10DOI: 10.1177/09596836231183066
J. Watling, Morgan Schmidt, M. Heckenberger, H. Lima, Bruno Moraes, K. Waura, H. Kuikuro, T. Kuikuro, Utu Kuikuro, Afukaka Kuikuro
The nature and extent of past indigenous transformations in the Amazon basin is an actively debated topic, and one that has important implications for both conservation policy and the cultural heritage of its indigenous and traditional populations. The use of charcoal and phytoliths to measure past human impacts in non-lacustrine settings has become especially influential in this debate but has also generated disagreement among scholars regarding the possible limits of these proxies for detecting ancient land-use. To contribute empirical data to this issue, our paper presents the first attempt to study charcoal and phytolith signals from areas of modern indigenous land-use, in the Xingu Indigenous Territory, southern Amazonia. Our findings show that, while charcoal and early successional herb phytoliths are good indicators of land-use intensity, certain types of land-use leave subtler traces in the phytolith record that can hinder their detection. We demonstrate how using finer sampling resolution and comparing local proxy data on their own terms are necessary steps in order to identify trends in human land-use across time and space.
{"title":"Assessing charcoal and phytolith signals for pre-Columbian land-use based on modern indigenous activity areas in the Upper Xingu, Amazonia","authors":"J. Watling, Morgan Schmidt, M. Heckenberger, H. Lima, Bruno Moraes, K. Waura, H. Kuikuro, T. Kuikuro, Utu Kuikuro, Afukaka Kuikuro","doi":"10.1177/09596836231183066","DOIUrl":"https://doi.org/10.1177/09596836231183066","url":null,"abstract":"The nature and extent of past indigenous transformations in the Amazon basin is an actively debated topic, and one that has important implications for both conservation policy and the cultural heritage of its indigenous and traditional populations. The use of charcoal and phytoliths to measure past human impacts in non-lacustrine settings has become especially influential in this debate but has also generated disagreement among scholars regarding the possible limits of these proxies for detecting ancient land-use. To contribute empirical data to this issue, our paper presents the first attempt to study charcoal and phytolith signals from areas of modern indigenous land-use, in the Xingu Indigenous Territory, southern Amazonia. Our findings show that, while charcoal and early successional herb phytoliths are good indicators of land-use intensity, certain types of land-use leave subtler traces in the phytolith record that can hinder their detection. We demonstrate how using finer sampling resolution and comparing local proxy data on their own terms are necessary steps in order to identify trends in human land-use across time and space.","PeriodicalId":50402,"journal":{"name":"Holocene","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45160744","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 : 2023-07-07DOI: 10.1177/09596836231183072
Jacob Freeman, R. Mauldin, M. Whisenhunt, R. Hard, John M. Anderies
We propose a model that may explain long-term population growth and decline events among human populations: The intensification of production generates a tradeoff between the adaptive capacity of individuals to generate a surplus of energy to maximize their fitness in the short-run and the long-term capacity of a population as a whole to experience a smooth transition into a demographic equilibrium. The model reconciles the conflicting insights of dynamic systems models of human population change, and we conduct a preliminary test of this model’s implications in Central Texas by developing time-series that estimate changes in human population density, modeled ecosystem productivity, human diet, and labor over the last 12,500 years. Our analysis indicates that Texas hunter-gatherers experienced three long-term population growth overshoots and recessions into quasi equilibria. Evidence indicates that each of these overshoots and recessions associate with changes in diet and labor devoted to processing high density, lower quality resources to unlock calories and nutrients. Over the long-term, population recessions may be necessary for populations to experiment with social and physical infrastructure changes that raise the carrying capacity of their environment.
{"title":"Repeated long-term population growth overshoots and recessions among hunter-gatherers","authors":"Jacob Freeman, R. Mauldin, M. Whisenhunt, R. Hard, John M. Anderies","doi":"10.1177/09596836231183072","DOIUrl":"https://doi.org/10.1177/09596836231183072","url":null,"abstract":"We propose a model that may explain long-term population growth and decline events among human populations: The intensification of production generates a tradeoff between the adaptive capacity of individuals to generate a surplus of energy to maximize their fitness in the short-run and the long-term capacity of a population as a whole to experience a smooth transition into a demographic equilibrium. The model reconciles the conflicting insights of dynamic systems models of human population change, and we conduct a preliminary test of this model’s implications in Central Texas by developing time-series that estimate changes in human population density, modeled ecosystem productivity, human diet, and labor over the last 12,500 years. Our analysis indicates that Texas hunter-gatherers experienced three long-term population growth overshoots and recessions into quasi equilibria. Evidence indicates that each of these overshoots and recessions associate with changes in diet and labor devoted to processing high density, lower quality resources to unlock calories and nutrients. Over the long-term, population recessions may be necessary for populations to experiment with social and physical infrastructure changes that raise the carrying capacity of their environment.","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":"46633136","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 : 2023-07-07DOI: 10.1177/09596836231183060
Leibin Wang, Haiwei Zhang, D. Zhang, Hai Cheng, Shengda Zhang, Teng Li, Yue Zhang, Xiaoqing Wang, Zhifeng Wu, Yafeng Wang, Fahu Chen
The cold and hypoxic environment of the Tibetan Plateau was a major challenge for its prehistoric human occupants. The earliest known hominin occupation (or visitation) of the Tibetan Plateau was at ~200 ka, in the middle Pleistocene, and these hominins must have had survival strategies for this harsh environment. We report the discovery of 5 handprints and 17 footprints on the travertine near the outlet of the Quesang hot spring, a well-documented archeological site with well-studied hominin hand and footprints on the Tibetan Plateau. Based on ichnological analysis and U-Th dating, we found that these intentional and unintentional traces were impressed during the early to middle Holocene. Combined with the 19 previously-dated hand and footprints from around the hot spring, we conclude that this site was attractive to ancient humans who made repeated visits over a long period. The strengthened monsoon in the early and middle Holocene may have promoted the expansion of prehistoric human activity onto the central Tibetan Plateau. The frequent human activities near the Quesang hot spring imply that the widespread hot springs on the Tibetan Plateau provided resources that facilitated human survival in this cold and dry plateau region.
{"title":"New evidence of prehistoric human activity on the central Tibetan plateau during the early to middle Holocene","authors":"Leibin Wang, Haiwei Zhang, D. Zhang, Hai Cheng, Shengda Zhang, Teng Li, Yue Zhang, Xiaoqing Wang, Zhifeng Wu, Yafeng Wang, Fahu Chen","doi":"10.1177/09596836231183060","DOIUrl":"https://doi.org/10.1177/09596836231183060","url":null,"abstract":"The cold and hypoxic environment of the Tibetan Plateau was a major challenge for its prehistoric human occupants. The earliest known hominin occupation (or visitation) of the Tibetan Plateau was at ~200 ka, in the middle Pleistocene, and these hominins must have had survival strategies for this harsh environment. We report the discovery of 5 handprints and 17 footprints on the travertine near the outlet of the Quesang hot spring, a well-documented archeological site with well-studied hominin hand and footprints on the Tibetan Plateau. Based on ichnological analysis and U-Th dating, we found that these intentional and unintentional traces were impressed during the early to middle Holocene. Combined with the 19 previously-dated hand and footprints from around the hot spring, we conclude that this site was attractive to ancient humans who made repeated visits over a long period. The strengthened monsoon in the early and middle Holocene may have promoted the expansion of prehistoric human activity onto the central Tibetan Plateau. The frequent human activities near the Quesang hot spring imply that the widespread hot springs on the Tibetan Plateau provided resources that facilitated human survival in this cold and dry plateau region.","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":"49355078","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 : 2023-07-07DOI: 10.1177/09596836231183065
Jordan Paillard, P. Richard, O. Blarquez, P. Grondin, Y. Bergeron
An isolated sugar maple (Acer saccharum Marsh.) stand is located in the boreal forest of Abitibi, about 75 km beyond its present northern range limit. When did this relatively thermophilous tree species establish after ice retreat? Were its populations more abundant than now sometimes in the past? If so, when and how did they expand then retracted? How did the species persist in boreal forest over time? What could have been the role of fire on this stand? To answer those questions, we reconstructed the postglacial fire and vegetation history from three lacustrine sediment sequences distributed along a c. 180 km latitudinal transect from southern boreal forests to the northern portion of deciduous forests. From north to south, those are lakes Labelle, Chasseur and Fur. We explored a procedure based on pollen accumulation rates in order to detect the probable presence of sugar maple within the lakes’ watershed. The procedure successfully indicates a sugar maple establishment c. 7800–5100 cal. BP at Fur, 5500–4400 cal. BP at Chasseur and c. 4000–2700 cal. BP at Labelle, in the north. At Fur, the subsequent sugar maple expansion happened 1 to 2 thousand years after establishment, during colder and moister climatic conditions favoring Pinus strobus L. replacement by Betula spp. c. 6000–5000 cal. BP. Sugar maple establishment, persistence or expansion is apparently not linked to a change in fire activity at Fur and Chasseur, but at Labelle, the species was more abundant during periods of shorter fire return intervals from 2000 to 500 years ago. Our study suggests that northern (Chasseur and Labelle) sugar maple establishment and possible expansion was probably more controlled by a complex interaction of inhibition and facilitation dynamics than by climate alone, a process reliant on the dominant vegetation’s composition and structure.
{"title":"Postglacial establishment and expansion of marginal populations of sugar maple in western Québec, Canada: Palynological detection and interactions with fire, climate and successional processes","authors":"Jordan Paillard, P. Richard, O. Blarquez, P. Grondin, Y. Bergeron","doi":"10.1177/09596836231183065","DOIUrl":"https://doi.org/10.1177/09596836231183065","url":null,"abstract":"An isolated sugar maple (Acer saccharum Marsh.) stand is located in the boreal forest of Abitibi, about 75 km beyond its present northern range limit. When did this relatively thermophilous tree species establish after ice retreat? Were its populations more abundant than now sometimes in the past? If so, when and how did they expand then retracted? How did the species persist in boreal forest over time? What could have been the role of fire on this stand? To answer those questions, we reconstructed the postglacial fire and vegetation history from three lacustrine sediment sequences distributed along a c. 180 km latitudinal transect from southern boreal forests to the northern portion of deciduous forests. From north to south, those are lakes Labelle, Chasseur and Fur. We explored a procedure based on pollen accumulation rates in order to detect the probable presence of sugar maple within the lakes’ watershed. The procedure successfully indicates a sugar maple establishment c. 7800–5100 cal. BP at Fur, 5500–4400 cal. BP at Chasseur and c. 4000–2700 cal. BP at Labelle, in the north. At Fur, the subsequent sugar maple expansion happened 1 to 2 thousand years after establishment, during colder and moister climatic conditions favoring Pinus strobus L. replacement by Betula spp. c. 6000–5000 cal. BP. Sugar maple establishment, persistence or expansion is apparently not linked to a change in fire activity at Fur and Chasseur, but at Labelle, the species was more abundant during periods of shorter fire return intervals from 2000 to 500 years ago. Our study suggests that northern (Chasseur and Labelle) sugar maple establishment and possible expansion was probably more controlled by a complex interaction of inhibition and facilitation dynamics than by climate alone, a process reliant on the dominant vegetation’s composition and structure.","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":"65189723","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 : 2023-07-07DOI: 10.1177/09596836231183069
A. Nesje
Glaciers and ice caps in Norway are presently undergoing mass loss, areal reduction, and frontal retreat, mainly a result of increased summer ablation due to rising summer temperatures over Scandinavia, especially after 2000 CE. In this paper, the glacier mass-balance response of 10 Norwegian glaciers with continuous mass balance observations (>10 years) to climate projections from 1971–2000 to 2071–2100 have been estimated. Projected changes in mean summer temperature and mean winter precipitation from 1971–2000 to 2071–2100, applying the RCP8.5 emission scenario for five different regions in Norway; ‘Sogn og Fjordane’ and ‘Hordaland’, now Vestland County in western Norway, ‘Oppland’, now part of Innlandet County in eastern Norway, and Nordland County and Finnmark County, both in Northern Norway), range between +3.5°C and +5.0°C, and between +5% and +25%, respectively. These climate projections have been converted (by linear regression with overlapping observational mass-balance data) into specific surface glacier mass balance [winter balance (Bw), summer balance (Bs), and annual balance (Ba) for 10 glaciers in Norway with mass-balance series [Ålfotbreen, Nigardsbreen (part of Jostedalsbreen), Austdalsbreen (part of Jostedalsbreen), Rembesdalskåka (part of Hardangerjøkulen), Blomstølskardsbreen (part of Søre Folgefonna), Storbrean, Hellstugubrean, Gråsubrean, Engabreen (part of Vestre Svartisen, Langfjordjøkelen (data: http://glacier.nve.no/glacier/viewer/ci/no/) yielding a total, cumulative surface glacier mass loss from 2000 to 2100 CE in the range of -85.2 ± 4 to -197.3 ± 10 m water equivalents. The estimated changes in equilibrium-line altitudes (ELAs), in the range of 230 ± 10 to 630 ± 30 m, indicate that the mean ELA may reach the upper part of 7 of the 10 glaciers included in this study [Ålfotbreen, Austdalsbreen, Rembesdalskåka, Blomstølskardsbreen, Gråsubrean, Engabreen and Langfjordjøkelen] by the end of the 21st century. The projected glacier mass loss and ELA rise, and thus changes in glacier length, area and volume, will most likely have profound consequences for future glacier hydrology (runoff), hydropower production, wildlife, ecosystems, glacier hazards, and tourism.
{"title":"Future state of Norwegian glaciers: Estimating glacier mass balance and equilibrium line responses to projected 21st century climate change","authors":"A. Nesje","doi":"10.1177/09596836231183069","DOIUrl":"https://doi.org/10.1177/09596836231183069","url":null,"abstract":"Glaciers and ice caps in Norway are presently undergoing mass loss, areal reduction, and frontal retreat, mainly a result of increased summer ablation due to rising summer temperatures over Scandinavia, especially after 2000 CE. In this paper, the glacier mass-balance response of 10 Norwegian glaciers with continuous mass balance observations (>10 years) to climate projections from 1971–2000 to 2071–2100 have been estimated. Projected changes in mean summer temperature and mean winter precipitation from 1971–2000 to 2071–2100, applying the RCP8.5 emission scenario for five different regions in Norway; ‘Sogn og Fjordane’ and ‘Hordaland’, now Vestland County in western Norway, ‘Oppland’, now part of Innlandet County in eastern Norway, and Nordland County and Finnmark County, both in Northern Norway), range between +3.5°C and +5.0°C, and between +5% and +25%, respectively. These climate projections have been converted (by linear regression with overlapping observational mass-balance data) into specific surface glacier mass balance [winter balance (Bw), summer balance (Bs), and annual balance (Ba) for 10 glaciers in Norway with mass-balance series [Ålfotbreen, Nigardsbreen (part of Jostedalsbreen), Austdalsbreen (part of Jostedalsbreen), Rembesdalskåka (part of Hardangerjøkulen), Blomstølskardsbreen (part of Søre Folgefonna), Storbrean, Hellstugubrean, Gråsubrean, Engabreen (part of Vestre Svartisen, Langfjordjøkelen (data: http://glacier.nve.no/glacier/viewer/ci/no/) yielding a total, cumulative surface glacier mass loss from 2000 to 2100 CE in the range of -85.2 ± 4 to -197.3 ± 10 m water equivalents. The estimated changes in equilibrium-line altitudes (ELAs), in the range of 230 ± 10 to 630 ± 30 m, indicate that the mean ELA may reach the upper part of 7 of the 10 glaciers included in this study [Ålfotbreen, Austdalsbreen, Rembesdalskåka, Blomstølskardsbreen, Gråsubrean, Engabreen and Langfjordjøkelen] by the end of the 21st century. The projected glacier mass loss and ELA rise, and thus changes in glacier length, area and volume, will most likely have profound consequences for future glacier hydrology (runoff), hydropower production, wildlife, ecosystems, glacier hazards, and tourism.","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":"45035482","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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