scholarly journals Evidence confirms an anthropic origin of Amazonian Dark Earths

2021 ◽  
Author(s):  
Umberto Lombardo ◽  
Manuel Arroyo-Kalin ◽  
Hans Huisman ◽  
Wenceslau Geraldes Teixeira ◽  
Charles R Clement ◽  
...  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lucas C. R. Silva ◽  
Rodrigo Studart Corrêa ◽  
Jamie L. Wright ◽  
Barbara Bomfim ◽  
Lauren Hendricks ◽  
...  

AbstractAmazonian Dark Earths (ADEs) are unusually fertile soils characterised by elevated concentrations of microscopic charcoal particles, which confer their distinctive colouration. Frequent occurrences of pre-Columbian artefacts at ADE sites led to their ubiquitous classification as Anthrosols (soils of anthropic origin). However, it remains unclear how indigenous peoples created areas of high fertility in one of the most nutrient-impoverished environments on Earth. Here, we report new data from a well-studied ADE site in the Brazilian Amazon, which compel us to reconsider its anthropic origin. The amounts of phosphorus and calcium—two of the least abundant macronutrients in the region—are orders of magnitude higher in ADE profiles than in the surrounding soil. The elevated levels of phosphorus and calcium, which are often interpreted as evidence of human activity at other sites, correlate spatially with trace elements that indicate exogenous mineral sources rather than in situ deposition. Stable isotope ratios of neodymium, strontium, and radiocarbon activity of microcharcoal particles also indicate exogenous inputs from alluvial deposition of carbon and mineral elements to ADE profiles,  beginning several thousands of years before the earliest evidence of soil management for plant cultivation in the region. Our data suggest that indigenous peoples harnessed natural processes of landscape formation, which led to the unique properties of ADEs, but were not responsible for their genesis. If corroborated elsewhere, this hypothesis would transform our understanding of human influence in Amazonia, opening new frontiers for the sustainable use of tropical landscapes going forward.


2007 ◽  
Vol 53 (3) ◽  
pp. 229-235 ◽  
Author(s):  
Satoshi Nakamura ◽  
Mario Hiraoka ◽  
Eiji Matsumoto ◽  
Kenji Tamura ◽  
Teruo Higashi

CATENA ◽  
2019 ◽  
Vol 172 ◽  
pp. 104-112 ◽  
Author(s):  
Jürgen Kern ◽  
Luise Giani ◽  
Wenceslau Teixeira ◽  
Giacomo Lanza ◽  
Bruno Glaser

2021 ◽  
Author(s):  
Marcel Lerch ◽  
Tobias Bromm ◽  
Clemens Geitner ◽  
Jean Nicolas Haas ◽  
Dieter Schäfer ◽  
...  

Abstract. The Ullafelsen at 1869 m a.s.l. in the Tyrolean Stubai Alps next to Innsbruck is an important (geo-)archaeological reference site for the Mesolithic period. Buried fireplaces on the Ullafelsen plateau were dated at 10.9–9.5 cal. kyrs BP and demonstrate together with thousands of flint stone artifacts the presence of hunter-gatherers during the Early Holocene. Most recently, we demonstrated the great potential of n-alkane and black carbon biomarkers for contributing to a better understanding of pedogenesis and landscape evolution. In order to study the importance of human and/or animals for occupation of this relevant geoarchaeological site, we carried out steroid and bile acid analyses on two modern faeces samples from cattle and sheep and on 37 soil samples from seven soil profiles at the Ullafelsen. The modern animal faeces show a dominance of 5β-stigmastanol and deoxycholic acid for ruminants (cattle and sheep), which is in agreement with literature data. The OAh horizons, which have accumulated and developed since the Mesolithic, revealed high contents of steroids and bile acids; the E (LL) horizon coinciding with the Mesolithic living floor is characterized by medium contents of steroids and bile acids. By contrast, the subsoil horizons Bh, Bs and BvCv contain low contents of faecal biomarkers indicating that leaching of steroids and bile acids into the podsolic subsoils is not an important factor. Deoxycholic acid is the most abundant bile acid in all soil samples and gives evidence for strong faeces input of ruminants. The steroid and bile acid patterns and ratios indicate a negligible input of human faeces on the Ullafelsen. β-Sitosterol as plant-derived steroid has also a strong influence on the faecal biomarker pattern in our soils. Root input into the subsoils is likely reflected by β-sitosterol contents. In conclusion, our results reflect a strong faecal input by livestock, rather than by humans as found for other Anthrosols such as Amazonian Dark Earths. Further studies need to focus on the question of the exact timing of faeces deposition.


2017 ◽  
Vol 26 (2) ◽  
pp. 136-143 ◽  
Author(s):  
Jens Soentgen ◽  
Klaus Hilbert ◽  
Carolin von Groote-Bidlingmaier ◽  
Gabriele Herzog-schröder ◽  
Eije Erich Pabst ◽  
...  

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