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Mohanty RB, Mishra AK, Mishra K, Yadava AK, Quamar MF, Barua IC, Kar R. Early onset of aridity in the past millennium: Insights from vegetation dynamics and climate change in the alpine, cold-desert region of Trans Himalaya, India. PLoS One 2024; 19:e0295785. [PMID: 38198444 PMCID: PMC10781162 DOI: 10.1371/journal.pone.0295785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 11/29/2023] [Indexed: 01/12/2024] Open
Abstract
Palynological analysis of surface soil and sub-surface sediments from the outwash plain of Hamtah Glacier, Lahaul-Spiti, India, has brought out the vegetation and climatic changes in the area during the last 1580 years. The arboreal and non-arboreal pollen ratio (AP/NAP) has been used to demarcate the different vegetation and climatic zones, complemented by the frequencies of the broad-leaved taxa. Lower values of thermophilous, broad-leaved arboreal taxa, indicate that the region experienced cold-arid conditions between 1580 and 1330 yr BP (AD 370-620); which can be related to the Dark Ages Cold Period (DACP). Thereafter, between 1330 and 950 yr BP (AD 620-1000), a rejuvenation of the broad-leaved elements reflects the initiation of a comparatively warm and moist phase, marking the Medieval Climatic Anomaly (MCA) in the region. The warm-moist phase was, however, short-lived, and from 950 yr BP to the Present (AD 1000 onwards), the region saw a return to cold-arid conditions, as evidenced by a sharp fall in the AP/NAP ratio. This cold-arid phase was, nevertheless, punctuated by a warm-moist period during 790 to 680 yr BP (AD 1160-1270), which marks the terminal phase of the MCA. After the termination of the MCA, the Little Ice Age (LIA) is well-marked in the area. The culmination of the long cold-arid regime is characterized by warmer conditions over the last 160 years, which is the manifestation of the Current Warm Period (CWP). Magnetic susceptibility (χlf) and sediment geochemistry (Weathering Index of Parker) were also attempted to have a multi-proxy approach, and show a general compatibility with the palynological data. The palaeoclimatic evidences suggest shorter warm periods and extended colder phases during the last 1580 years; in this high-altitude, cold-desert, Trans Himalayan region.
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Affiliation(s)
| | - Amit K. Mishra
- Birbal Sahni Institute of Palaeosciences, Lucknow, India
| | - Kriti Mishra
- Central Ground Water Board, North Western Region, Chandigarh, India
| | | | - M. Firoze Quamar
- Birbal Sahni Institute of Palaeosciences, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Iswar C. Barua
- Department of Agronomy, Assam Agricultural University, Jorhat, India
| | - Ratan Kar
- Birbal Sahni Institute of Palaeosciences, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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Zhao L, Dong X, Liu X, Wang N, Eastoe CJ, Wei N, Xie C, Liu H, Han C, Hua T, Wang L. Extreme precipitation stable isotopic compositions reveal unexpected summer monsoon incursions in the Qilian Mountains. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 900:165743. [PMID: 37495157 DOI: 10.1016/j.scitotenv.2023.165743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 07/16/2023] [Accepted: 07/21/2023] [Indexed: 07/28/2023]
Abstract
Isotope composition and moisture sources of precipitation are important for understanding water cycles and reconstructing paleoclimate. Based on 15-years' precipitation stable Isotope composition (δ18O and δ2H) from four stations of the Qilian Mountains, we found unique δ18O and δ2H features associated with the incursion of the summer monsoon over the Qilian Mountains, northwestern China. In 12 of the 15 years, similar seasonal variations of δ18O and δ2H confirmed a dominant source of moisture from Westerly circulation, and higher intercepts of the local meteoric water line (LMWL) indicated strong recycling of continental moisture. However, in August 2016 and 2018, extremely low slopes and intercepts of the LMWL, and more negative δ18O and δ2H revealed substantial contributions of the Asian summer monsoon to precipitation of the Qilian Mountains, with extremely heavy precipitation in August 2016. The column moisture flux, land-sea thermal contrast, correlations of precipitation δ18O with East Asian Summer Monsoon Index and Westerlies Index, HYSPLIT modeling results and precipitation δ18O along backward trajectories confirmed incursions of the summer monsoon in August 2016 and 2018. Our redefining of the boundary of the summer monsoon region confirmed the summer monsoon incursion zone can extend to the west of longitude 96°E and north of latitude 40°N in strong monsoon years, corresponding to boundaries of monsoon incursions in the mid-Holocene. Temperature correlated with precipitation δ18O at monthly and shorter time scales, but not for whole seasons or at yearly scale, revealing that summer monsoon incursions are therefore more likely than changing temperature to explain the multi-year cycles in the Qilian Mountains ice archives. Continent-scale shifts in atmospheric circulation strongly influence water resources in the Qilian mountains, and may change in frequency as climate warms. This study therefore has important implications for understanding water resources in the Qilian mountains in the past and into the future.
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Affiliation(s)
- Liangju Zhao
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China.
| | - Xiying Dong
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Xiaohong Liu
- School of Geography and Tourism, Shaanxi Normal University, Xi'an 710119, China
| | - Ninglian Wang
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Christopher J Eastoe
- Department of Geosciences (retired), University of Arizona, Tucson, AZ 85721, USA
| | - Na Wei
- Climate Centre of Shaanxi Province, Xi'an 710049, China
| | - Cong Xie
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Hang Liu
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Chuntan Han
- Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Ting Hua
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Lixin Wang
- Department of Earth Sciences, Indiana University-Purdue University Indianapolis (IUPUI), Indianapolis, IN 46202, USA
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3
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Tian Y, Fleitmann D, Zhang Q, Sha L, Wassenburg JA, Axelsson J, Zhang H, Li X, Hu J, Li H, Zhao L, Cai Y, Ning Y, Cheng H. Holocene climate change in southern Oman deciphered by speleothem records and climate model simulations. Nat Commun 2023; 14:4718. [PMID: 37543627 PMCID: PMC10404270 DOI: 10.1038/s41467-023-40454-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 07/28/2023] [Indexed: 08/07/2023] Open
Abstract
Qunf Cave oxygen isotope (δ18Oc) record from southern Oman is one of the most significant of few Holocene Indian summer monsoon cave records. However, the interpretation of the Qunf δ18Oc remains in dispute. Here we provide a multi-proxy record from Qunf Cave and climate model simulations to reconstruct the Holocene local and regional hydroclimate changes. The results indicate that besides the Indian summer monsoon, the North African summer monsoon also contributes water vapor to southern Oman during the early to middle Holocene. In principle, Qunf δ18Oc values reflect integrated oxygen-isotope fractionations over a broad moisture transport swath from moisture sources to the cave site, rather than local precipitation amount alone, and thus the Qunf δ18Oc record characterizes primary changes in the Afro-Asian monsoon regime across the Holocene. In contrast, local climate proxies appear to suggest an overall slightly increased or unchanged wetness over the Holocene at the cave site.
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Affiliation(s)
- Ye Tian
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Dominik Fleitmann
- Department of Environmental Sciences, University of Basel, Basel, 4054, Switzerland
| | - Qiong Zhang
- Department of Physical Geography and the Bolin Centre for Climate Change, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Lijuan Sha
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Jasper A Wassenburg
- Center for Climate Physics, Institute for Basic Science, Busan, 46241, Republic of Korea
- Pusan National University, Busan, 46241, Republic of Korea
| | - Josefine Axelsson
- Department of Physical Geography and the Bolin Centre for Climate Change, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Haiwei Zhang
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Xianglei Li
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China
| | - Jun Hu
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
| | - Hanying Li
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Liang Zhao
- School of Geography, Nanjing Normal University, Nanjing, 210023, China
| | - Yanjun Cai
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Youfeng Ning
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Hai Cheng
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, 710049, China.
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.
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Xiang L, Huang X, Sun M, Panizzo VN, Huang C, Zheng M, Chen X, Chen F. Prehistoric population expansion in Central Asia promoted by the Altai Holocene Climatic Optimum. Nat Commun 2023; 14:3102. [PMID: 37248221 DOI: 10.1038/s41467-023-38828-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 05/17/2023] [Indexed: 05/31/2023] Open
Abstract
How climate change in the middle to late Holocene has influenced the early human migrations in Central Asian Steppe remains poorly understood. To address this issue, we reconstructed a multiproxy-based Holocene climate history from the sediments of Kanas Lake and neighboring Tiewaike Lake in the southern Altai Mountains. The results show an exceptionally warm climate during ~6.5-3.6 kyr is indicated by the silicon isotope composition of diatom silica (δ30Sidiatom) and the biogenic silica (BSi) content. During 4.7-4.3 kyr, a peak in δ30Sidiatom reflects enhanced lake thermal stratification and periodic nutrient limitation as indicated by concomitant decreasing BSi content. Our geochemical results indicate a significantly warm and wet climate in the Altai Mountain region during 6.5-3.6 kyr, corresponding to the Altai Holocene Climatic Optimum (AHCO), which is critical for promoting prehistoric human population expansion and intensified cultural exchanges across the Central Asian steppe during the Bronze Age.
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Affiliation(s)
- Lixiong Xiang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, 730000, Lanzhou, China
| | - Xiaozhong Huang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, 730000, Lanzhou, China.
| | - Mingjie Sun
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, 730000, Lanzhou, China
- Centre for Environmental Geochemistry, School of Geography, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Virginia N Panizzo
- Centre for Environmental Geochemistry, School of Geography, University of Nottingham, Nottingham, NG7 2RD, UK.
| | - Chong Huang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, 730000, Lanzhou, China
| | - Min Zheng
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, 730000, Lanzhou, China
| | - Xuemei Chen
- Northwest Institute of Eco-Environmental and Resources, Chinese Academy of Sciences, 730000, Lanzhou, China
| | - Fahu Chen
- Alpine Paleoecology and Human Adaptation Group (ALPHA), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, 100101, Beijing, China
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), 100101, Beijing, China
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5
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Dunbar R. Why did doctrinal religions first appear in the Northern Subtropical Zone? EVOLUTIONARY HUMAN SCIENCES 2023; 5:e15. [PMID: 37587936 PMCID: PMC10427489 DOI: 10.1017/ehs.2023.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 05/01/2023] [Accepted: 05/02/2023] [Indexed: 08/18/2023] Open
Abstract
Doctrinal religions that involve recognised gods, more formal theologies, moral codes, dedicated religious spaces and professional priesthoods emerged in two phases during the Neolithic. Almost all of these appeared in a narrow latitudinal band (the northern Subtropical Zone). I suggest that these developments were the result of a need to facilitate community bonding in response to scalar stresses that developed as community sizes increased dramatically beyond those typical of hunter-gatherer societies. Conditions for population growth (as indexed by rainfall patterns and the difference between pathogen load and the length of the growing season) were uniquely optimised in this zone, creating an environment of ecological release in which populations could grow unusually rapidly. The relationship between latitude, religion and language in contemporary societies suggests that the peculiar characteristics of the northern (but not the southern) Subtropical Zone were especially favourable for the evolution of large scale religions as a way of enforcing community cohesion.
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Affiliation(s)
- R.I.M. Dunbar
- Department of Experimental Psychology, University of Oxford, Radcliffe Observatory Quarter, Oxford OX2 6GG, UK
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Hou J, Ji K, Zhu E, Dong G, Tong T, Chu G, Liu W, Wu W, Zhang S, Guedes JD, Chen F. Climate change fostered rise and fall of the Tibetan Empire during 600-800 AD. Sci Bull (Beijing) 2023:S2095-9273(23)00294-3. [PMID: 37179230 DOI: 10.1016/j.scib.2023.04.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/09/2023] [Accepted: 04/10/2023] [Indexed: 05/15/2023]
Abstract
During the 7-9th century, the Tibetan Empire constituted a superpower between the Tang Empire and Abbasid Caliphate: one that played significant roles in geopolitics in Asia during the Early Medieval Period. The factors which led to the rise and rapid decline of this powerful Empire, the only united historical regime on the Tibetan Plateau (TP), remain unclear. Sub-annual scale precipitation and decadal-scale temperature records of the central TP are presented, indicating that the height of this Empire coincided with a two-century long interval of uncharacteristically warm and humid climate. The ameliorated climate enabled the expansion of arable land and increased agricultural production. The close relationship between the precipitation records and historical events implied that the Empire implemented flexible strategies to tackle the effects of climate changes. This has implications for agricultural production in alpine regions including the TP, in the context of current global warming.
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Affiliation(s)
- Juzhi Hou
- Group of Alpine Paleoecology and Human Adaptation, State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kejia Ji
- Group of Alpine Paleoecology and Human Adaptation, State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Erlei Zhu
- Group of Alpine Paleoecology and Human Adaptation, State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Guanghui Dong
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Tao Tong
- Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710, China
| | - Guoqiang Chu
- Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Weiguo Liu
- Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Wenxiang Wu
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Shuilong Zhang
- Key Laboratory of Network Information System Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jade D'Alpoim Guedes
- Scripps Institution of Oceanography, Department of Anthropology, University of California San Diego, San Diego CA 92093, USA
| | - Fahu Chen
- Group of Alpine Paleoecology and Human Adaptation, State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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7
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Out-of-phase relationship of Holocene moisture variations between the northeastern and southeastern Tibetan Plateau and its societal impacts. FUNDAMENTAL RESEARCH 2023. [DOI: 10.1016/j.fmre.2023.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
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8
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Protracted Indian monsoon droughts of the past millennium and their societal impacts. Proc Natl Acad Sci U S A 2022; 119:e2207487119. [PMID: 36122235 PMCID: PMC9522357 DOI: 10.1073/pnas.2207487119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protracted droughts lasting years to decades constitute severe threats to human welfare across the Indian subcontinent. Such events are, however, rare during the instrumental period (ca. since 1871 CE). In contrast, the historic documentary evidence indicates the repeated occurrences of protracted droughts in the region during the preinstrumental period implying that either the instrumental observations underestimate the full spectrum of monsoon variability or the historic accounts overestimate the severity and duration of the past droughts. Here we present a temporally precise speleothem-based oxygen isotope reconstruction of the Indian summer monsoon precipitation variability from Mawmluh cave located in northeast India. Our data reveal that protracted droughts, embedded within multidecadal intervals of reduced monsoon rainfall, frequently occurred over the past millennium. These extreme events are in striking temporal synchrony with the historically documented droughts, famines, mass mortality events, and geopolitical changes in the Indian subcontinent. Our findings necessitate reconsideration of the region's current water resources, sustainability, and mitigation policies that discount the possibility of protracted droughts in the future.
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9
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Sharma BB, Singh S, Sharma KK, Sharma AK, Suraj KP, Mahmood T, Samaria KU, Kant S, Singh N, Singh T, Singh A, Gupta R, Koul PA, Salvi S, Singh V. Proportionate clinical burden of respiratory diseases in Indian outdoor services and its relationship with seasonal transitions and risk factors: The results of SWORD survey. PLoS One 2022; 17:e0268216. [PMID: 35981008 PMCID: PMC9387816 DOI: 10.1371/journal.pone.0268216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 04/26/2022] [Indexed: 11/18/2022] Open
Abstract
Background The Global Burden of Disease data suggest that respiratory diseases contribute to high morbidity in India. However, the factors responsible for high morbidity are not quite clear. Therefore, the Seasonal Waves Of Respiratory Disorders (SWORD) study was planned to estimate the point prevalence due to respiratory diseases in Indian OPD services and its association with risk factors and change in seasons. Methods In this point prevalence observational multicenter study conducted during 2017–18, participating physicians recorded information of consecutive patients in response to a questionnaire. The study was conducted on four predetermined days representing transition of Indian seasons i.e., February (winter), May (summer), August (monsoon), and November (autumn). Results The eligible number of patients from across 302 sites in India was 25,177. The mean age of study population was 46.1±18.1 years, 14102(56.0%) were males and 11075(44.0%) females. The common diagnoses were: asthma(29.8%), chronic obstructive pulmonary disease (COPD),15.6%, respiratory tract infections (RTIs),11.3%, and tuberculosis(8.7%). All these conditions showed significant seasonal trends (Asthma 31.4% autumn vs. 26.5% summer, COPD 21.1% winter vs. 8.1% summer, RTIs 13.3% winter vs. 4.3% summer, and tuberculosis 12.5% autumn vs. 4.1% summer, p<0.001 for each respectively). After adjustment for risk factors, asthma was significantly associated with exposure to molds (OR:1.12,CI:1.03–1.22), pet animals (OR:1.07,CI:1.01–1.14), recent-travel (OR:1.22,CI:1.13–1.32), and rain-wetting (OR:1.27,CI:1.15–1.40); and RTIs with rain-wetting (OR:1.53,CI:1.34–1.74), and recent-travel (OR:1.17,CI:1.05–1.30). Conclusions The SWORD study showed wide seasonal variations in outpatient attendance of patients with common respiratory conditions. Novel risk-factors associated with respiratory diseases were also identified.
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Affiliation(s)
- Bharat Bhushan Sharma
- Department of Medicine, Division of Allergy and Pulmonary Medicine, S.M.S. Medical College, Jaipur, Rajasthan, India
| | - Sheetu Singh
- Department of Respiratory Medicine, Lung Center, Rajasthan Hospital, Jaipur, Rajasthan, India
| | - Krishna Kumar Sharma
- Department of Pharmacology, Lal Bahadur College of Pharmacy, Rajasthan University of Health Sciences, Jaipur, Rajasthan, India
| | - Arvind Kumar Sharma
- Department of Community Medicine, Mahatma Gandhi Medical College, Jaipur, Rajasthan, India
| | - K. P. Suraj
- Department of Pulmonary Medicine, Government Medical College, Kozhikode, Kerala, India
| | - Tariq Mahmood
- Department of Pulmonary Medicine, MLN Medical College, Prayagraj (Allahabad), Uttar Pradesh, India
| | | | - Surya Kant
- Department of Respiratory Medicine, King George’s Medical University, Lucknow, Uttar Pradesh, India
| | - Nishtha Singh
- Department of Respiratory Medicine, Asthma Bhawan, Jaipur, Rajasthan, India
| | - Tejraj Singh
- Department of Research Division, Asthma Bhawan, Jaipur, Rajasthan, India
| | - Aradhana Singh
- Department of Medicine, S.M.S. Medical College, Jaipur, Rajasthan, India
| | - Rajeev Gupta
- Department of Preventive Cardiology and Internal Medicine, Eternal Heart Care Centre and Research Institute, Mount Sinai New York Affiliate, Jaipur, Rajasthan, India
| | - Parvaiz A. Koul
- Department of Internal and Pulmonary Medicine, SKIMS, Srinagar, Jammu and Kashmir, India
| | - Sundeep Salvi
- Pulmocare Research and Education Foundation, Pune, Maharashtra, India
| | - Virendra Singh
- Department of Pulmonary Medicine, Director, Rajasthan Hospital & Asthma Bhawan, Jaipur, Rajasthan, India
- * E-mail:
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10
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Yang B, Qin C, Bräuning A, Osborn TJ, Trouet V, Ljungqvist FC, Esper J, Schneider L, Grießinger J, Büntgen U, Rossi S, Dong G, Yan M, Ning L, Wang J, Wang X, Fan B, Wang S, Luterbacher J, Cook ER, Stenseth NC. Reply to Weiss: Tree-ring stable oxygen isotopes suggest an increase in Asian monsoon rainfall at 4.2 ka BP. Proc Natl Acad Sci U S A 2022; 119:e2204067119. [PMID: 35561221 PMCID: PMC9171909 DOI: 10.1073/pnas.2204067119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Affiliation(s)
- Bao Yang
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Chun Qin
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Achim Bräuning
- Institute of Geography, Friedrich-Alexander-University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Timothy J. Osborn
- Climatic Research Unit, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Valerie Trouet
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ 85721
| | - Fredrik Charpentier Ljungqvist
- Department of History, Stockholm University, 106 91 Stockholm, Sweden
- Bolin Centre for Climate Research, Stockholm University, 106 91 Stockholm, Sweden
- Swedish Collegium for Advanced Study, 752 38 Uppsala, Sweden
| | - Jan Esper
- Department of Geography, Johannes Gutenberg University, 55099 Mainz, Germany
| | - Lea Schneider
- Department of Geography, Justus-Liebig-University, D-35390 Giessen, Germany
| | - Jussi Grießinger
- Institute of Geography, Friedrich-Alexander-University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Ulf Büntgen
- Department of Geography, University of Cambridge, CB2 3EN Cambridge, United Kingdom
- Dendrosciences Group, Swiss Federal Research Institute for Forest, Snow, and Landscape Research, CH-8903 Birmensdorf, Switzerland
- Czech Globe Global Change Research Institute, Czech Academy of Sciences, 60300 Brno, Czech Republic
- Department of Geography, Faculty of Science, Masaryk University, 61137 Brno, Czech Republic
| | - Sergio Rossi
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC G7H 2B1, Canada
| | - Guanghui Dong
- Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Mi Yan
- Key Laboratory of Virtual Geographic Environment of Ministry of Education, School of Geography Science, Nanjing Normal University, Nanjing 210023, China
| | - Liang Ning
- Key Laboratory of Virtual Geographic Environment of Ministry of Education, School of Geography Science, Nanjing Normal University, Nanjing 210023, China
| | - Jianglin Wang
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Xiaofeng Wang
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Beixi Fan
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Suming Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Jürg Luterbacher
- Science and Innovation Department, World Meteorological Organization, CH-1211 Geneva, Switzerland
| | - Edward R. Cook
- Tree Ring Laboratory, Lamont Doherty Earth Observatory of Columbia University, Palisades, NY 10964
| | - Nils Chr. Stenseth
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, N-0316 Oslo, Norway
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11
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Jiang Q, Meng B, Wang Z, Qian P, Zheng J, Jiang J, Zhao C, Hou J, Dong G, Shen J, Liu W, Liu Z, Chen F. Exceptional terrestrial warmth around 4200-2800 years ago in Northwest China. Sci Bull (Beijing) 2022; 67:427-436. [PMID: 36546094 DOI: 10.1016/j.scib.2021.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 01/06/2023]
Abstract
One of the Holocene abrupt events around 4200 years ago, lasting for ∼ 200 years, is thought to have caused cultural disruptions, yet terrestrial climatic status right after the cold/dry event remains poorly defined and is often presumed that a generally cool condition prevailed during the Bronze Age (∼ 4000-2200 years ago). Here we report an alkenone-based summer temperature record over the past ∼ 12,000 years, in addition to two updated alkenone records, from Northwest China, providing new insights into the climatic status right after the event. Our results indicate that exceptional terrestrial warmth, up to ∼ 6 °C, occurred around 4200-2800 years ago during the Bronze Age, superimposed on the long-term Holocene cooling trend. The exceptional warmth in Northwest China, together with other climate anomalies elsewhere, suggests an unusual large-scale climatic reorganization at 4200-2800 years ago when solar activity remained high, with important implications to the climate background for cultural developments during the Bronze Age.
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Affiliation(s)
- Qingfeng Jiang
- Institute of Geographic Engineering Technology, School of Geography Sciences, Nantong University, Nantong 210093, China
| | - Bowen Meng
- Department of Earth Sciences, the University of Hong Kong, Hong Kong, China
| | - Zheng Wang
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xi'an 710061, China
| | - Peng Qian
- Institute of Geographic Engineering Technology, School of Geography Sciences, Nantong University, Nantong 210093, China
| | - Jianan Zheng
- Institute of Geographic Engineering Technology, School of Geography Sciences, Nantong University, Nantong 210093, China
| | - Jiawei Jiang
- Department of Earth Sciences, the University of Hong Kong, Hong Kong, China
| | - Cheng Zhao
- School of Geography and Marine Science, Nanjing University, Nanjing 210046, China
| | - Juzhi Hou
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Guanghui Dong
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Ji Shen
- School of Geography and Marine Science, Nanjing University, Nanjing 210046, China; State Key Laboratory of Lake Sciences and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Weiguo Liu
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xi'an 710061, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Zhonghui Liu
- Department of Earth Sciences, the University of Hong Kong, Hong Kong, China.
| | - Fahu Chen
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
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12
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Palaeoenvironmental proxies indicate long-term development of agro-pastoralist landscapes in Inner Asian mountains. Sci Rep 2022; 12:554. [PMID: 35017595 PMCID: PMC8752612 DOI: 10.1038/s41598-021-04546-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/24/2021] [Indexed: 11/25/2022] Open
Abstract
A growing body of archaeological research on agro-pastoralist populations of the Inner Asian mountains indicates that these groups adapted various systems of mobile herding and cultivation to ecotopes across the region from as early as 5000 BP. It has been argued that these adaptations allowed the development of flexible social-ecological systems well suited to the long-term management of these mountain landscapes. At present, less attention has been paid to examining the long-term ecological legacy of these adaptations within the sedimentary or palaeoenvironmental record. Here we present sediment, palynomorph and charcoal data that we interpret as indicating agro-pastoralist environmental perturbations, taken from three cores at middle and high altitudes in the Kashmir Valley at the southern end of the Inner Asian mountains. Our data indicate spatially and temporally discontinuous patterns of agro-pastoralist land use beginning close to 4000 BP. Periods of intensification of upland herding are often coincident with phases of regional social or environmental change, in particular we find the strongest signals for agro-pastoralism in the environmental record contemporary with regionally arid conditions. These patterns support previous arguments that specialised agro-pastoralist ecologies across the region are well placed to respond to past and future climate deteriorations. Our data indicating long-term co-evolution of humans and landscape in the study area also have implications for the ongoing management of environments generally perceived as “pristine” or “wilderness”.
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13
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Hydroclimate change in the Garhwal Himalaya, India at 4200 yr BP coincident with the contraction of the Indus civilization. Sci Rep 2021; 11:23082. [PMID: 34845269 PMCID: PMC8630182 DOI: 10.1038/s41598-021-02496-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/17/2021] [Indexed: 11/18/2022] Open
Abstract
High-resolution analysis of a 3.80 m sediment core recovered from Deoria Tal, a mid-elevation lake located at 2393 m a.s.l. in the Garhwal Himalaya, documents long-term and abrupt hydroclimate fluctuations in northern India during the mid- to late Holocene. The sediment chronology, based on ten 14C dates, indicates the core spans 5200 years. Non-destructive, radiological imaging approaches (X-ray fluorescence (XRF), X-ray imaging, and CT scans) were used to assess the response of the lake system to changing hydroclimatic conditions. Variations in elemental concentrations and sediment density evidenced notable hydroclimate change episodes centered at 4850, 4200, and 3100 cal yr BP. Elevated detrital input, greater sediment density, decreased lake ventilation, and lower autochthonous productivity reflects lake deepening between 4350 and 4200 cal yr BP. An abrupt shift in elemental concentrations and sediment density indicated the onset of lake drawdown at 4200 cal yr BP and a negative hydroclimate anomaly between 4200 and 4050 cal yr BP. Lower detrital flux, decreased sediment density, increased oxygenation, and higher autochthonous productivity, reflects a reduction in lake volume between 3200 and 3100 cal yr BP. The potential link between abrupt climate change at 4200 cal yr BP and the contraction of the Indus civilization is explored.
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14
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Riedel N, Fuller DQ, Marwan N, Poretschkin C, Basavaiah N, Menzel P, Ratnam J, Prasad S, Sachse D, Sankaran M, Sarkar S, Stebich M. Monsoon forced evolution of savanna and the spread of agro-pastoralism in peninsular India. Sci Rep 2021; 11:9032. [PMID: 33907218 PMCID: PMC8079367 DOI: 10.1038/s41598-021-88550-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 04/09/2021] [Indexed: 11/30/2022] Open
Abstract
An unresolved issue in the vegetation ecology of the Indian subcontinent is whether its savannas, characterized by relatively open formations of deciduous trees in C4-grass dominated understories, are natural or anthropogenic. Historically, these ecosystems have widely been regarded as anthropogenic-derived, degraded descendants of deciduous forests. Despite recent work showing that modern savannas in the subcontinent fall within established bioclimatic envelopes of extant savannas elsewhere, the debate persists, at least in part because the regions where savannas occur also have a long history of human presence and habitat modification. Here we show for the first time, using multiple proxies for vegetation, climate and disturbances from high-resolution, well-dated lake sediments from Lonar Crater in peninsular India, that neither anthropogenic impact nor fire regime shifts, but monsoon weakening during the past ~ 6.0 kyr cal. BP, drove the expansion of savanna at the expense of forests in peninsular India. Our results provide unambiguous evidence for a climate-induced origin and spread of the modern savannas of peninsular India at around the mid-Holocene. We further propose that this savannization preceded and drove the introduction of agriculture and development of sedentism in this region, rather than vice-versa as has often been assumed.
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Affiliation(s)
- Nils Riedel
- Research Station of Quaternary Palaeontology, Senckenberg Research Institute, Am Jakobskirchhof 4, 99423, Weimar, Germany.
| | - Dorian Q Fuller
- Institute of Archaeology, University College London, 31-34 Gordon Square, London, WC1H 0PY, UK
| | - Norbert Marwan
- Potsdam Institute of Climate Impact Research, Telegrafenberg A56, 14412, Potsdam, Germany
| | - Constantin Poretschkin
- Nees Institute for Biodiversity of Plants, University of Bonn, Meckenheimer Allee 170, 53115, Bonn, Germany
| | - Nathani Basavaiah
- Indian Institute of Geomagnetism, Nanabhai Moos Marg, Navy Nagar, Colaba, Mumbai, Maharashtra, 400005, India
| | - Philip Menzel
- Centre for Marine and Atmospheric Sciences, University of Hamburg, Bundesstraße 53, 20146, Hamburg, Germany
| | - Jayashree Ratnam
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Canara Bank Layout, Rajiv Gandhi Nagar, Kodigehalli, Bengaluru, Karnataka, 560065, India
| | - Sushma Prasad
- Institute of Earth and Environmental Sciences, University of Potsdam, Karl-Liebknecht-Straße 24/25, 14476, Potsdam, Germany
| | - Dirk Sachse
- Institute of Earth and Environmental Sciences, University of Potsdam, Karl-Liebknecht-Straße 24/25, 14476, Potsdam, Germany
| | - Mahesh Sankaran
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Canara Bank Layout, Rajiv Gandhi Nagar, Kodigehalli, Bengaluru, Karnataka, 560065, India
| | - Saswati Sarkar
- Institute of Earth and Environmental Sciences, University of Potsdam, Karl-Liebknecht-Straße 24/25, 14476, Potsdam, Germany
| | - Martina Stebich
- Research Station of Quaternary Palaeontology, Senckenberg Research Institute, Am Jakobskirchhof 4, 99423, Weimar, Germany
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15
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Kulkarni C, Finsinger W, Anand P, Nogué S, Bhagwat SA. Synergistic impacts of anthropogenic fires and aridity on plant diversity in the Western Ghats: Implications for management of ancient social-ecological systems. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 283:111957. [PMID: 33493997 DOI: 10.1016/j.jenvman.2021.111957] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/21/2020] [Accepted: 01/04/2021] [Indexed: 06/12/2023]
Abstract
Identifying the impacts of anthropogenic fires on biodiversity is imperative for human-influenced tropical rainforests because: i) these ecosystems have been transformed by human-induced fires for millennia; and ii) their effective management is essential for protecting the world's terrestrial biodiversity in the face of global environmental change. While several short-term studies elucidate the impacts of fires on local plant diversity, how plant diversity responds to fire regimes over long timescales (>100 years) is a significant knowledge gap, posing substantial impediment to evidence-based management of tropical social-ecological systems. Using wet evergreen forests of the Western Ghats of India as a model system, we discuss the synergistic effects of anthropogenic fires and enhanced aridity on tropical plant diversity over the past 4000 years by examining fossil pollen-based diversity indices (e.g., pollen richness and evenness, and temporal β-diversity), past fire management, the intervals of enhanced aridity due to reduced monsoon rainfall and land use history. By developing a historical perspective, our aim is to provide region-specific management information for biodiversity conservation in the Western Ghats. We observe that the agroforestry landscape switches between periods of no fires (4000-1800 yr BP, and 1400-400 yr BP) and fires (1800-1400 yr BP, and 400-0 yr BP), with both fire periods concomitant with intervals of enhanced aridity. We find synergistic impacts of anthropogenic fires and aridity on plant diversity uneven across time, pointing towards varied land management strategies implemented by the contemporary societies. For example, during 1800-1400 yr BP, diversity reduced in conjunction with a significant decrease in the canopy cover related to sustained use of fires, possibly linked to large-scale intensification of agriculture. On the contrary, the substantially reduced fires during 400-0 yr BP may be associated with the emergence of sacred forest groves, a cultural practice supporting the maintenance of plant diversity. Overall, notwithstanding apparent changes in fires, aridity, and land use over the past 4000 years, present-day plant diversity in the Western Ghats agroforestry landscape falls within the range of historical variability. Importantly, we find a strong correlation between plant diversity and canopy cover, emphasising the crucial role of maintenance of trees in the landscape for biodiversity conservation. Systematic tree management in tropical social-ecological systems is vital for livelihoods of billions of people, who depend on forested landscapes. In this context, we argue that agroforestry landscapes can deliver win-win solutions for biodiversity as well as people in the Western Ghats and wet tropics at large.
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Affiliation(s)
- Charuta Kulkarni
- Department of Geography and OpenSpace Research Centre, The Open University, Milton Keynes, MK7 6AA, United Kingdom.
| | - Walter Finsinger
- ISEM, Univ Montpellier, CNRS, EPHE, IRD, 34095, Montpellier Cedex 5, France
| | - Pallavi Anand
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, MK7 6AA, United Kingdom
| | - Sandra Nogué
- School of Geography and Environmental Science, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom; Oxford Long-Term Ecology Laboratory, Department of Zoology, University of Oxford, Oxford, OX1 3SZ, United Kingdom
| | - Shonil A Bhagwat
- Department of Geography and OpenSpace Research Centre, The Open University, Milton Keynes, MK7 6AA, United Kingdom; Oxford Long-Term Ecology Laboratory, Department of Zoology, University of Oxford, Oxford, OX1 3SZ, United Kingdom
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16
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Das R, Ivanisenko VA, Anashkina AA, Upadhyai P. The story of the lost twins: decoding the genetic identities of the Kumhar and Kurcha populations from the Indian subcontinent. BMC Genet 2020; 21:117. [PMID: 33092524 PMCID: PMC7583313 DOI: 10.1186/s12863-020-00919-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 11/10/2022] Open
Abstract
Background The population structure of the Indian subcontinent is a tapestry of extraordinary diversity characterized by the amalgamation of autochthonous and immigrant ancestries and rigid enforcement of sociocultural stratification. Here we investigated the genetic origin and population history of the Kumhars, a group of people who inhabit large parts of northern India. We compared 27 previously published Kumhar SNP genotype data sampled from Uttar Pradesh in north India to various modern day and ancient populations. Results Various approaches such as Principal Component Analysis (PCA), Admixture, TreeMix concurred that Kumhars have high ASI ancestry, minimal Steppe component and high genomic proximity to the Kurchas, a small and relatively little-known population found ~ 2500 km away in Kerala, south India. Given the same, biogeographical mapping using Geographic Population Structure (GPS) assigned most Kumhar samples in areas neighboring to those where Kurchas are found in south India. Conclusions We hypothesize that the significant genomic similarity between two apparently distinct modern-day Indian populations that inhabit well separated geographical areas with no known overlapping history or links, likely alludes to their common origin during or post the decline of the Indus Valley Civilization (estimated by ALDER). Thereafter, while they dispersed towards opposite ends of the Indian subcontinent, their genomic integrity and likeness remained preserved due to endogamous social practices. Our findings illuminate the genomic history of two Indian populations, allowing a glimpse into one or few of numerous of human migrations that likely occurred across the Indian subcontinent and contributed to shape its varied and vibrant evolutionary past.
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Affiliation(s)
- Ranajit Das
- Yenepoya Research Centre (YRC), Yenepoya (Deemed to be University), Mangalore, Karnataka, India.
| | - Vladimir A Ivanisenko
- Humanitarian Institute, Novosibirsk State University, 630090, Novosibirsk, Russia.,Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia
| | - Anastasia A Anashkina
- The Digital Health Institute, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia.,Engelhardt Institute of Molecular Biology RAS, Moscow, Russia
| | - Priyanka Upadhyai
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India
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17
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Malik N. Uncovering transitions in paleoclimate time series and the climate driven demise of an ancient civilization. CHAOS (WOODBURY, N.Y.) 2020; 30:083108. [PMID: 32872795 DOI: 10.1063/5.0012059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
We present a hybrid framework appropriate for identifying distinct dynamical regimes and transitions in a paleoclimate time series. Our framework combines three powerful techniques used independently of each other in time series analysis: a recurrence plot, manifold learning through Laplacian eigenmaps, and Fisher information metric. The resulting hybrid approach achieves a more automated classification and visualization of dynamical regimes and transitions, including in the presence of missing values, observational noise, and short time series. We illustrate the capabilities of the method through several pragmatic numerical examples. Furthermore, to demonstrate the practical usefulness of the method, we apply it to a recently published paleoclimate dataset: a speleothem oxygen isotope record from North India covering the past 5700 years. This record encodes the patterns of monsoon rainfall over the region and covers the critically important period during which the Indus Valley Civilization matured and declined. We identify a transition in monsoon dynamics, indicating a possible connection between climate change and the decline of the Indus Valley Civilization.
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Affiliation(s)
- Nishant Malik
- School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York 14623, USA
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18
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Naidu PD, Ganeshram R, Bollasina MA, Panmei C, Nürnberg D, Donges JF. Coherent response of the Indian Monsoon Rainfall to Atlantic Multi-decadal Variability over the last 2000 years. Sci Rep 2020; 10:1302. [PMID: 31992786 PMCID: PMC6987308 DOI: 10.1038/s41598-020-58265-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 12/21/2019] [Indexed: 11/14/2022] Open
Abstract
Indian Summer Monsoon (ISM) rainfall has a direct effect on the livelihoods of two billion people in the Indian-subcontinent. Yet, our understanding of the drivers of multi-decadal variability of the ISM is far from being complete. In this context, large-scale forcing of ISM rainfall variability with multi-decadal resolution over the last two millennia is investigated using new records of sea surface salinity (δ18Ow) and sea surface temperatures (SSTs) from the Bay of Bengal (BoB). Higher δ18Ow values during the Dark Age Cold Period (1550 to 1250 years BP) and the Little Ice Age (700 to 200 years BP) are suggestive of reduced ISM rainfall, whereas lower δ18Ow values during the Medieval Warm Period (1200 to 800 years BP) and the major portion of the Roman Warm Period (1950 to 1550 years BP) indicate a wetter ISM. This variability in ISM rainfall appears to be modulated by the Atlantic Multi-decadal Oscillation (AMO) via changes in large-scale thermal contrast between the Asian land mass and the Indian Ocean, a relationship that is also identifiable in the observational data of the last century. Therefore, we suggest that inter-hemispheric scale interactions between such extra tropical forcing mechanisms and global warming are likely to be influential in determining future trends in ISM rainfall.
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Affiliation(s)
| | - Raja Ganeshram
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | | | - Champoungam Panmei
- CSIR-National Institute of Oceanography, Dona Paula, 403004, Goa, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-NIO, Goa, India
| | | | - Jonathan F Donges
- Postdam Institute for Climate Impact Research, P.O. Box 601203, D-14412, Postdam, Germany
- Planetary Boundary Research Lab, Stockholm Resilience Center, Stockholm University, Stockholm, Sweden
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19
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Azevedo V, Stríkis NM, Santos RA, de Souza JG, Ampuero A, Cruz FW, de Oliveira P, Iriarte J, Stumpf CF, Vuille M, Mendes VR, Cheng H, Edwards RL. Medieval Climate Variability in the eastern Amazon-Cerrado regions and its archeological implications. Sci Rep 2019; 9:20306. [PMID: 31889126 PMCID: PMC6937329 DOI: 10.1038/s41598-019-56852-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 12/03/2019] [Indexed: 12/02/2022] Open
Abstract
The South American Monsoon System is responsible for the majority of precipitation in the continent, especially over the Amazon and the tropical savannah, known as ‘Cerrado’. Compared to the extensively studied subtropical and temperate regions the effect of the Medieval Climate Anomaly (MCA) on the precipitation over the tropics is still poorly understood. Here, we present a multiproxy paleoprecipitation reconstruction showing a consistent change in the hydrologic regime during the MCA in the eastern Amazon and ‘Cerrado’, characterized by a substantial transition from humid to drier conditions during the Early (925-1150 C.E.) to Late-MCA (1150-1350 C.E.). We compare the timing of major changes in the monsoon precipitation with the expansion and abandonment of settlements reported in the archeological record. Our results show that important cultural successions in the pre-Columbian Central Amazon, the transition from Paredão to Guarita phase, are in agreement with major changes in the hydrologic regime. Phases of expansion and, subsequent abandonment, of large settlements from Paredão during the Early to Late-MCA are coherent with a reduction in water supply. In this context we argue that the sustained drier conditions during the latter period may have triggered territorial disputes with Guarita leading to the Paredão demise.
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Affiliation(s)
- Vitor Azevedo
- Geochemistry Department, Fluminense Federal University, 24020-141, Niterói, Brazil.
| | - Nicolás M Stríkis
- Geochemistry Department, Fluminense Federal University, 24020-141, Niterói, Brazil
| | - Rudney A Santos
- Geosciences Institute, University of São Paulo, 05508-0 80, São Paulo, Brazil
| | | | - Angela Ampuero
- Geochemistry Department, Fluminense Federal University, 24020-141, Niterói, Brazil
| | - Francisco W Cruz
- Geosciences Institute, University of São Paulo, 05508-0 80, São Paulo, Brazil
| | - Paulo de Oliveira
- Geosciences Institute, University of São Paulo, 05508-0 80, São Paulo, Brazil
| | - José Iriarte
- Department of Archeology, University of Exeter, Exeter, UK
| | - Cintia F Stumpf
- Geociences Institute, University of Brasília, 70910-900, Brasília, Brazil
| | - Mathias Vuille
- Department of Atmospheric and Environmental Sciences, University at Albany, Albany, NY, USA
| | - Vinícius R Mendes
- Marine Science Department, Federal University of São Paulo, 11050-020, Santos, Brazil
| | - Hai Cheng
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China.,Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, USA
| | - R Lawrence Edwards
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, USA
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20
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Mariani L, Cola G, Maghradze D, Failla O, Zavatti F. Influence of climate cycles on grapevine domestication and ancient migrations in Eurasia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 635:1240-1254. [PMID: 29710578 DOI: 10.1016/j.scitotenv.2018.04.175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/10/2018] [Accepted: 04/10/2018] [Indexed: 06/08/2023]
Abstract
The objective of this work is to investigate the Holocenic climate cycles that may have influenced the domestication of grapevine in the Subcaucasian area and its subsequent spread in Eurasia. The analysis covered the longitudinal belt ranging from the Iberian Peninsula to Japan, seen as the preferential pathway for the Holocenic spread of grapevine and many other crops in Eurasia. Spectral analysis was considered as the criterion of investigation and the Holocenic cycles were analyzed considering different geochemical and biological proxies, of which seven are directly referred to vine. In this context the relation of the abovementioned proxies with spectral peaks of possible causal factors like Solar activity (SA), North Atlantic oceanic factors (Atlantic Multidecadal Oscillation - AMO and North Atlantic Oscillation - NAO), and subtropical oceanic factors (El Nino Southern Oscillation - ENSO) was also analyzed. In order to acquire a sufficiently wide number of proxies sensitive to the causal factors, we referred to a latitudinal belt wider than the one colonized by vine, also acquiring proxy from the Scandinavian area, notoriously susceptible to North Atlantic forcings. The analysis of the proxy spectral peaks, considering 20 classes with a 50-years step in the 0-1000 years range, showed that the 50% of the classes have a higher frequency of peaks at East than West, the 20% a higher frequency at West than East and the 10% an equal frequency, showing the efficiency of the propagation of Western signals towards the center of Eurasia. The search of the causal factors spectral peaks in the proxy series showed that AMO, NAO and SA acted with a certain regularity on the entire belt investigated both latitudinally and longitudinally, while spectral peaks linked to ENSO underwent a considerable attenuation moving northward. Finally, the specific analysis on viticultural proxies showed common peaks with causal factors.
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Affiliation(s)
- Luigi Mariani
- Lombardy Museum of Agricultural History, Sant'Angelo Lodigiano, Italy
| | - Gabriele Cola
- Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università degli studi di Milano, Milan, Italy.
| | - David Maghradze
- Faculty of Agrarian Sciences and Biosystems Engineering, Georgian Technical University, Tbilisi, Georgia; National Wine Agency of Georgia, Tbilisi, Georgia
| | - Osvaldo Failla
- Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università degli studi di Milano, Milan, Italy
| | - Franco Zavatti
- Lombardy Museum of Agricultural History, Sant'Angelo Lodigiano, Italy
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