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 Convergent Estimates of Biomass Burning-Derived Atmospheric Ammonia in Peninsular Southeast Asia

2021 ◽  
Author(s):  
Yunhua Chang ◽  
Yan-Lin Zhang ◽  
Sawaeng Kawichai ◽  
Qian Wang ◽  
Martin Van Damme ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Biomass Burning ◽  
Atmospheric Chemistry ◽  
Isotope Composition ◽  
Anthropogenic Activities ◽  
Nitrogen Isotope ◽  
Environmental Consequences ◽  
Relative Contribution ◽  
Tropical Monsoon ◽  
Rural Sites

Abstract. Ammonia (NH3) is an important agent involved in atmospheric chemistry and nitrogen cycling. Current estimates of NH3 emissions from biomass burning (BB) differ by more than a factor of two, impeding a reliable assessment of their environmental consequences. Combining high-resolution satellite observations of NH3 columns with network measurements of the concentration and stable nitrogen isotope composition (δ15N) of NH3, we present coherent estimates on the amount of NH3 derived from BB in the heartland of Southeast Asia, a tropical monsoon environment. Our results reveal a strong variability of atmospheric NH3 levels in time and space across different landscapes. All evidence in hand suggests that anthropogenic activities are the most important modulating control with regards to the observed patterns of NH3 distribution in the study area. N-isotope balance considerations revealed that during the intensive fire period, the atmospheric input from BB accounts for not more than 21 ± 5 % (1σ) of the ambient NH3, even at the rural sites and in the proximity of burning areas. Our N-isotope based assessment of the variation of the relative contribution of BB-derived NH3 is further validated independently through the measurements of particulate K+, a chemical tracer of BB. Our findings underscore that BB-induced NH3 emissions in the tropical monsoon environments can be much lower than previously anticipated, with important implications for future modeling studies to better constrain the climate and air quality effects of wildfires.

Carbon isotope composition as indicator for climatic changes during the middle and late Holocene in a peat bog from Maramureş Mountains (Romania)

The Holocene ◽  
2013 ◽  
Vol 24 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Gabriela Cristea ◽  
Stela Maria Cuna ◽  
Sorina Fărcaş ◽  
Ioan Tanţău ◽  
Edina Dordai ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Late Holocene ◽  
Isotope Composition ◽  
Climatic Changes ◽  
Carbon Isotope Composition ◽  
Peat Bog ◽  
Middle And Late Holocene

scholarly journals Late Holocene spread of pastoralism coincides with endemic megafaunal extinction on Madagascar

2021 ◽  
Vol 288 (1955) ◽  
pp. 20211204
Author(s):  
Sean W. Hixon ◽  
Kristina G. Douglass ◽  
Brooke E. Crowley ◽  
Lucien Marie Aimé Rakotozafy ◽  
Geoffrey Clark ◽  
...  
Keyword(s):  
Late Holocene ◽  
Nitrogen Isotope ◽  
Bone Collagen ◽  
Zebu Cattle ◽  
Radiocarbon Dates ◽  
Arrival Times ◽  
Carbon And Nitrogen ◽  
Exotic Animals ◽  
Isotope Data ◽  
Introduced Herbivores

Recently expanded estimates for when humans arrived on Madagascar (up to approximately 10 000 years ago) highlight questions about the causes of the island's relatively late megafaunal extinctions (approximately 2000–500 years ago). Introduced domesticated animals could have contributed to extinctions, but the arrival times and past diets of exotic animals are poorly known. To conduct the first explicit test of the potential for competition between introduced livestock and extinct endemic megafauna in southern and western Madagascar, we generated new radiocarbon and stable carbon and nitrogen isotope data from the bone collagen of introduced ungulates (zebu cattle, ovicaprids and bushpigs, n = 66) and endemic megafauna (pygmy hippopotamuses, giant tortoises and elephant birds, n = 68), and combined these data with existing data from endemic megafauna ( n = 282, including giant lemurs). Radiocarbon dates confirm that introduced and endemic herbivores briefly overlapped chronologically in this region between 1000 and 800 calibrated years before present (cal BP). Moreover, stable isotope data suggest that goats, tortoises and hippos had broadly similar diets or exploited similar habitats. These data support the potential for both direct and indirect forms of competition between introduced and endemic herbivores. We argue that competition with introduced herbivores, mediated by opportunistic hunting by humans and exacerbated by environmental change, contributed to the late extinction of endemic megafauna on Madagascar.

scholarly journals Convergent evidence for the pervasive but limited contribution of biomass burning to atmospheric ammonia in peninsular Southeast Asia

2021 ◽  
Vol 21 (9) ◽  
pp. 7187-7198
Author(s):  
Yunhua Chang ◽  
Yan-Lin Zhang ◽  
Sawaeng Kawichai ◽  
Qian Wang ◽  
Martin Van Damme ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Biomass Burning ◽  
Atmospheric Chemistry ◽  
Isotope Composition ◽  
Anthropogenic Activities ◽  
Nitrogen Isotope ◽  
Environmental Consequences ◽  
Relative Contribution ◽  
Tropical Monsoon ◽  
Rural Sites

Abstract. Ammonia (NH3) is an important agent involved in atmospheric chemistry and nitrogen cycling. Current estimates of NH3 emissions from biomass burning (BB) differ by more than a factor of 2, impeding a reliable assessment of their environmental consequences. Combining high-resolution satellite observations of NH3 columns with network measurements of the concentration and stable nitrogen isotope composition (δ15N) of NH3, we present coherent estimates of the amount of NH3 derived from BB in the heartland of Southeast Asia, a tropical monsoon environment. Our results reveal a strong variability in atmospheric NH3 levels in time and space across different landscapes. All of the evidence on hand suggests that anthropogenic activities are the most important modulating control with respect to the observed patterns of NH3 distribution in the study area. N-isotope balance considerations revealed that during the intensive fire period, the atmospheric input from BB accounts for no more than 21±5 % (1σ) of the ambient NH3, even at the rural sites and in the proximity of burning areas. Our N-isotope-based assessment of the variation in the relative contribution of BB-derived NH3 is further validated independently through the measurements of particulate K+, a chemical tracer of BB. Our findings underscore that BB-induced NH3 emissions in tropical monsoon environments can be much lower than previously anticipated, with important implications for future modeling studies to better constrain the climate and air quality effects of wildfires.

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>

Carbon and Nitrogen Isotope Composition of the Wood of Pinus sylvestris, Betula pendula and Populus tremula

2020 ◽  
Vol 54 (8) ◽  
pp. 819-824
Author(s):  
P. Yu. Voronin ◽  
V. A. Mukhin ◽  
T. A. Velivetskaya ◽  
A. V. Ignatiev ◽  
Vl. V. Kuznetsov
Keyword(s):  
Pinus Sylvestris ◽  
Betula Pendula ◽  
Isotope Composition ◽  
Nitrogen Isotope ◽  
Populus Tremula ◽  
Carbon And Nitrogen ◽  
Nitrogen Isotope Composition

scholarly journals Nitrogen isotope effects can be used to diagnose N transformations in wastewater anammox systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paul M. Magyar ◽  
Damian Hausherr ◽  
Robert Niederdorfer ◽  
Nicolas Stöcklin ◽  
Jing Wei ◽  
...  
Keyword(s):  
Isotope Effect ◽  
Isotope Composition ◽  
Isotope Effects ◽  
Nitrogen Isotope ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Experimental Conditions ◽  
N Transformations ◽  
Natural Systems ◽  
Inverse Isotope Effect

AbstractAnaerobic ammonium oxidation (anammox) plays an important role in aquatic systems as a sink of bioavailable nitrogen (N), and in engineered processes by removing ammonium from wastewater. The isotope effects anammox imparts in the N isotope signatures (15N/14N) of ammonium, nitrite, and nitrate can be used to estimate its role in environmental settings, to describe physiological and ecological variations in the anammox process, and possibly to optimize anammox-based wastewater treatment. We measured the stable N-isotope composition of ammonium, nitrite, and nitrate in wastewater cultivations of anammox bacteria. We find that the N isotope enrichment factor 15ε for the reduction of nitrite to N2 is consistent across all experimental conditions (13.5‰ ± 3.7‰), suggesting it reflects the composition of the anammox bacteria community. Values of 15ε for the oxidation of nitrite to nitrate (inverse isotope effect, − 16 to − 43‰) and for the reduction of ammonium to N2 (normal isotope effect, 19–32‰) are more variable, and likely controlled by experimental conditions. We argue that the variations in the isotope effects can be tied to the metabolism and physiology of anammox bacteria, and that the broad range of isotope effects observed for anammox introduces complications for analyzing N-isotope mass balances in natural systems.

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