scholarly journals Multi-proxy approach to reconstruct Middle and Late Holocene paleoenvironment and climate in the eastern Carpathians.

2020 ◽  
Author(s):  
Maria J. Ramos-Roman ◽  
Heikki Seppä ◽  
Eniko Magyari ◽  
Cindy De Jonge ◽  
Daniel Veres ◽  
...  
Keyword(s):  
Late Holocene ◽  
Climate Changes ◽  
Organic Geochemistry ◽  
Lipid Biomarkers ◽  
The Black Sea ◽  
Radiocarbon Dates ◽  
Past Climate ◽  
Eastern Carpathians ◽  
Complementary Techniques ◽  
Middle And Late Holocene

<p>Sediments from lakes are a useful climate archive that provides information about past climate changes and human impact. It is well-known that abrupt climate change can be the trigger of the collapse or migrations of past civilizations. To have a better understanding of the migration of the Yamnaya civilization, located west of the Black Sea at ~5.5-5 cal kyr BP, we hypothesize that past climate changes acts as a driver of this migration. To test this we focus on a sedimentary record retrieved from the Mocearu lake that is located at 780 m a.s.l. in the Buzau mountains (eastern Carpathians, Romania). The record has a length of 7 m and covers the last ~6.5 cal kyr BP based on AMS radiocarbon dates. To reconstruct vegetation, environment and climate during the Middle and Late Holocene, we use complementary techniques: pollen, inorganic (XRF-analysis) and organic geochemistry based on lipid biomarkers (brGDGTs). The reconstruction has been carried out with higher resolution during the Middle Holocene, with the objective of finding evidence of the climatic changes that may have occurred around 5 cal kyr BP. Based on preliminary radiocarbon dating, the climatic reconstruction (based on brGDGTs) shows an increase in temperature from ~6 to 5.5 cal kyr BP, followed by a prominent decrease ~5.3-5 cal kyr BP.</p>

Climate change and human disturbance of fynbos vegetation during the late Holocene at Princess Vlei, Western Cape, South Africa

The Holocene ◽  
2011 ◽  
Vol 21 (7) ◽  
pp. 1137-1149 ◽  
Author(s):  
F.H. Neumann ◽  
L. Scott ◽  
M.K. Bamford
Keyword(s):  
Anthropogenic Disturbance ◽  
Late Holocene ◽  
Climate Changes ◽  
Western Cape ◽  
Radiocarbon Dates ◽  
The Core ◽  
Pollen Types ◽  
Hydrological System ◽  
Vegetation And Climate ◽  
Floating Mat

Pollen analysis of a core in Princess Vlei in the Fynbos Biome near Cape Town gives a 4150 year record of vegetation and climate changes followed by disturbance by colonial settlers since c. 300 years ago. Their impact replaced climate as a major factor in changing the vegetation. The chronology is based on eight radiocarbon dates. Pollen types such as Restionaceae, Ericaceae, and Proteaceae reflect changes in fynbos. Pollen indicators at the bottom of the core suggest drier conditions followed by an increase in Morella, Cyperaceae and Carpacoce pollen, which might indicate moist conditions c. 3400–2600 cal. yr BP. Drier conditions prevail c. 2600–1900 cal. yr BP. Apparent light disturbance after c. 2000 cal. yr BP might be attributed to Khoi herders. Deeper water and damp surroundings are indicated c. 1900–1000 cal. yr BP. The top of the core shows an increase of Poaceae while Restionaceae decrease with anthropogenic disturbance, including the introduction of neophytes such as Pinus ( c. 300 years ago) and Zea mays. Charcoal percentages point to intense fires after the arrival of the Europeans. Water between 105 and 75 cm indicates the development of a floating mat resulting from changes in the hydrological system possibly connected to disturbances by settlers.

Holocene Vegetation and Paleoclimatic and Paleomagnetic History from Lake Johnston, Tasmania

2001 ◽  
Vol 56 (2) ◽  
pp. 264-274 ◽  
Author(s):  
Sharon A. Anker ◽  
Eric A. Colhoun ◽  
Charles E. Barton ◽  
Mike Peterson ◽  
Mike Barbetti
Keyword(s):  
Magnetic Susceptibility ◽  
Master Curve ◽  
Late Holocene ◽  
Climate Changes ◽  
Holocene Climate ◽  
Radiocarbon Dates ◽  
Southeastern Australia ◽  
Lagarostrobos Franklinii ◽  
Glacial Relict ◽  
Vegetation And Climate

AbstractLake Johnston cirque contains some of the best subalpine rainforest in Tasmania. Pollen from the sediments shows Lagarostrobos franklinii, which presently reaches 1040 m, may be a glacial relict. Nothofagus cunninghamii–Nothofagus gunnii subalpine rainforest developed between 9000 and 6000 14C yr B.P., with a maximum at 8700 14C yr B.P. After 6000 14C yr B.P. Nothofagus gunnii became more important, and from 3600 14C yr B.P. sclerophyll and heath components increased. Partial burning of the catchment occurred periodically. Early Holocene climate was warmer and wetter than late Holocene climate. The vegetation and climate changes are similar to those recorded from western South Island New Zealand and Chile. Radiocarbon dates give a sedimentation rate of 0.43 mm/yr. Cores are correlated by magnetic susceptibility. Magnetic ages are assigned by matching with the 14C-dated secular variation master curve for southeastern Australia. Magnetic ages are consistent with the 14C chronology when the former are adjusted by 350 years.

scholarly journals Fishing intensification as response to Late Holocene socio-ecological instability in southeastern South America

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alice Toso ◽  
Ellen Hallingstad ◽  
Krista McGrath ◽  
Thiago Fossile ◽  
Christine Conlan ◽  
...  
Keyword(s):  
South America ◽  
Late Holocene ◽  
Isotope Composition ◽  
Nitrogen Isotope ◽  
Radiocarbon Dates ◽  
Relative Contribution ◽  
Isotopic Baseline ◽  
Isotope Mixing Models ◽  
Social Units ◽  
Middle And Late Holocene

AbstractThe emergence of plant-based economies have dominated evolutionary models of Middle and Late Holocene pre-Columbian societies in South America. Comparatively, the use of aquatic resources and the circumstances for intensifying their exploitation have received little attention. Here we reviewed the stable carbon and nitrogen isotope composition of 390 human individuals from Middle and Late Holocene coastal sambaquis, a long-lasting shell mound culture that flourished for nearly 7000 years along the Atlantic Forest coast of Brazil. Using a newly generated faunal isotopic baseline and Bayesian Isotope Mixing Models we quantified the relative contribution of marine resources to the diet of some of these groups. Through the analysis of more than 400 radiocarbon dates we show that fishing sustained large and resilient populations during most of the Late Holocene. A sharp decline was observed in the frequency of sambaqui sites and radiocarbon dates from ca. 2200 years ago, possibly reflecting the dissolution of several nucleated groups into smaller social units, coinciding with substantial changes in coastal environments. The spread of ceramics from ca. 1200 years ago is marked by innovation and intensification of fishing practices, in a context of increasing social and ecological instability in the Late Holocene.

scholarly journals Fishing intensification as response to Late Holocene socio-ecological instability in southeastern South America

2021 ◽  
Author(s):  
Alice Toso ◽  
Ellen Hallingstad ◽  
Krista McGrath ◽  
Thiago Fossile ◽  
Christine Conlan ◽  
...  
Keyword(s):  
Late Holocene ◽  
Isotope Composition ◽  
Nitrogen Isotope ◽  
Radiocarbon Dates ◽  
Carbon And Nitrogen ◽  
Relative Contribution ◽  
Isotopic Baseline ◽  
Isotope Mixing Models ◽  
Social Units ◽  
Middle And Late Holocene

Abstract The emergence of plant-based economies have dominated evolutionary models of Middle and Late Holocene pre-Columbian societies. Comparatively, the use of aquatic resources and the circumstances for intensifying their exploitation, have received little attention. Here we reviewed the stable carbon and nitrogen isotope composition of 390 human individuals from Middle and Late Holocene coastal sambaquis, a long-lasting shell mound culture that flourished for nearly 7000 years along the Atlantic Forest coast of Brazil. Using a newly generated faunal isotopic baseline and Bayesian Isotope Mixing Models we quantified the relative contribution of marine resources to the diet of some of these groups. Through the analysis of more than 400 radiocarbon dates we show that fishing sustained large and resilient populations during most of the Late Holocene. A sharp decline was observed in the chronology of non-ceramic sites from ca. 2200 years ago, possibly reflecting the dissolution of several nucleated groups into smaller social units, coinciding with substantial changes in coastal environments. The adoption of ceramics from ca. 1200 years ago is marked by innovation and intensification of fishing practices, in a context of increasing social and ecological instability in the Late Holocene.

scholarly journals d4PDF: large-ensemble and high-resolution climate simulations for global warming risk assessment

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Masayoshi Ishii ◽  
Nobuhito Mori
Keyword(s):  
Risk Assessment ◽  
Global Warming ◽  
High Resolution ◽  
Climate Changes ◽  
Future Climate ◽  
Atmospheric Models ◽  
Large Ensemble ◽  
Past Climate ◽  
The Past ◽  
Climate Simulations

Abstract A large-ensemble climate simulation database, which is known as the database for policy decision-making for future climate changes (d4PDF), was designed for climate change risk assessments. Since the completion of the first set of climate simulations in 2015, the database has been growing continuously. It contains the results of ensemble simulations conducted over a total of thousands years respectively for past and future climates using high-resolution global (60 km horizontal mesh) and regional (20 km mesh) atmospheric models. Several sets of future climate simulations are available, in which global mean surface air temperatures are forced to be higher by 4 K, 2 K, and 1.5 K relative to preindustrial levels. Nonwarming past climate simulations are incorporated in d4PDF along with the past climate simulations. The total data volume is approximately 2 petabytes. The atmospheric models satisfactorily simulate the past climate in terms of climatology, natural variations, and extreme events such as heavy precipitation and tropical cyclones. In addition, data users can obtain statistically significant changes in mean states or weather and climate extremes of interest between the past and future climates via a simple arithmetic computation without any statistical assumptions. The database is helpful in understanding future changes in climate states and in attributing past climate events to global warming. Impact assessment studies for climate changes have concurrently been performed in various research areas such as natural hazard, hydrology, civil engineering, agriculture, health, and insurance. The database has now become essential for promoting climate and risk assessment studies and for devising climate adaptation policies. Moreover, it has helped in establishing an interdisciplinary research community on global warming across Japan.

scholarly journals Late-Holocene landscape evolution and human presence in the northern Danube delta (Chilia distributary lobes)

The Holocene ◽  
2021 ◽  
pp. 095968362110191
Author(s):  
Luminița Preoteasa ◽  
Alfred Vespremeanu-Stroe ◽  
Anca Dan ◽  
Laurențiu Țuțuianu ◽  
Cristian Panaiotu ◽  
...  
Keyword(s):  
Middle Ages ◽  
Economic History ◽  
Late Holocene ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Sedimentary Facies ◽  
The Black Sea ◽  
Danube Delta ◽  
Human Presence ◽  
Historical Texts

This paper documents the Late-Holocene environmental changes and human presence in the northern Danube delta using a multidisciplinary approach that combines geoscientific data with archaeological findings, historical texts, and maps. It follows the formation and progression of the Chilia distributary and the reconfiguration of socioeconomic activities. Sedimentary facies identified on five new cores by changes in texture properties, magnetic susceptibility, geochemistry, and macro- and microfauna composition together with the newly obtained chronology constrain the complex evolution of the Chilia branch as filling in a long-lasting bay and then of a giant lagoon (Thiagola) which covered most of the northern delta since the Old Danube lobe inception (ca. 7500 yrs BP) till modern Chilia development. It initiated during the Greek Antiquity (ca. 2500 yrs ar BP) at the delta apex, while in Roman times (ca. 1800 yrs BP) it pursued its slow flowing into the vast Thiagola Lagoon. The most dramatic transformations occurred in the last 800 years when the river passed east of the Chilia promontory, rapidly went through the present-day Matița-Merhei basin (several decades), and created its first open-sea outlet. Solid discharge increased in two distinct periods, once in the Middle Ages (ca. 750 yrs BP) and then in the Modern Period (ca. 150 yrs BP) due to human-induced land-use changes in the Danube watershed. The chronology of the cultural remains on the pre-deltaic Chilia promontory and the multiproxy analysis of a sediment core retrieved nearby downstream suggest the terrestrial connection of the island with the mainland in ancient times. The hitherto contended issue of the old Thiagola Lagoon and its location are redefined here, as are the original identifications of ancient and medieval toponyms and hydronyms, especially for Chilia-Licostomo, Byzantine, Genoese, Moldavian, Ottoman, and Russian trading point of great importance in the political and economic history of the Black Sea and neighboring regions.

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