Spatiotemporal Variations of Riverine Discharge Within the Amazon Basin During the Late Holocene Coincide With Extratropical Temperature Anomalies

AbstractLocated at the northwestern part of the Amazon basin, Rio Negro is the largest black-water river in the world and is one of the poorest studied regions of the Amazon lowlands. In the middle-upper part of the Rio Negro were retrieved sediment cores form Lake Acarabixi, which were analyzed using pollen, spores, charcoal, and geochemistry. The aim of this study was to detect the influences from humans and river dynamics on the vegetation history in the region. Two main periods of vegetation and river dynamics were detected. From 10,840 to 8240 cal yr BP, the river had a direct influence into the lake. The lake had a regional input of charcoal particles, which reflected the effect of the dry Holocene period in the basin. Furthermore, highland taxa such asHedyosmumandMyrsinewere found at that time along with igapó forest species that are characteristic to tolerate extended flooding likeEschweilera,Macrolobium, Myrtaceae,Swartzia, andAstrocaryum. During the late Holocene (1600 to 650 cal yr BP), more lacustrine phases were observed. There were no drastic changes in vegetation but the presence of pioneer species likeVismiaandCecropia, along with the signal of fires, which pointed to human disturbances.

Download Full-text

Did pre-Columbian populations of the Amazonian biome reach carrying capacity during the Late Holocene?

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2019.0715 ◽

2020 ◽

Vol 376 (1816) ◽

pp. 20190715 ◽

Cited By ~ 2

Author(s):

Manuel Arroyo-Kalin ◽

Philip Riris

Keyword(s):

Carrying Capacity ◽

Human Population ◽

Late Holocene ◽

Amazon Basin ◽

Population Change ◽

Relative Population ◽

Robust Model ◽

Recent Developments ◽

European Colonization ◽

Procurement Strategies

The increasingly better-known archaeological record of the Amazon basin, the Orinoco basin and the Guianas both questions the long-standing premise of a pristine tropical rainforest environment and also provides evidence for major biome-scale cultural and technological transitions prior to European colonization. Associated changes in pre-Columbian human population size and density, however, are poorly known and often estimated on the basis of unreliable assumptions and guesswork. Drawing on recent developments in the aggregate analysis of large radiocarbon databases, here we present and examine different proxies for relative population change between 1050 BC and AD 1500 within this broad region. By using a robust model testing approach, our analyses document that the growth of pre-Columbian human population over the 1700 years prior to European colonization adheres to a logistic model of demographic growth. This suggests that, at an aggregate level, these pre-Columbian populations had potentially reached carrying capacity (however high) before the onset of European colonization. Our analyses also demonstrate that this aggregate scenario shows considerable variability when projected geographically, highlighting significant gaps in archaeological knowledge yet also providing important insights into the resilience of past human food procurement strategies. By offering a new understanding of biome-wide pre-Columbian demographic trends based on empirical evidence, our analysis hopes to unfetter novel perspectives on demic expansions, language diversification trajectories and subsistence intensification processes in the Amazonian biome during the late Holocene. This article is part of the theme issue ‘Cross-disciplinary approaches to prehistoric demography’.

Download Full-text

Archaeological history of Middle Holocene environmental change from fish proxies at the Monte Castelo archaeological shell mound, Southwestern Amazonia

The Holocene ◽

10.1177/0959683620941108 ◽

2020 ◽

Vol 30 (11) ◽

pp. 1606-1621

Author(s):

Gabriela Prestes-Carneiro ◽

Philippe Béarez ◽

Francisco Pugliese ◽

Myrtle Pearl Shock ◽

Carlos Augusto Zimpel ◽

...

Keyword(s):

Late Holocene ◽

Amazon Basin ◽

High Water ◽

Ecological Niches ◽

Human Occupation ◽

Middle Holocene ◽

Long Term Stability ◽

Drought Tolerant ◽

Fish Remains ◽

Aquatic Landscapes

Monte Castelo, an archeological shell mound located on the southwestern periphery of the Amazon basin, is an artificial forest island occupied from the Middle to late-Holocene, and it contains one of the longest, continuous sequences of human occupation anywhere in the basin. Analysis of fish remains investigates fluctuations in the fish communities that are markers of changes in the paleoenvironment. The 8112 taxonomically identified remains document diagnostic taxa that are drought-tolerant (armoured catfishes, swamp-eels and tiger fishes) and from swampy environments, indicating probable occupation during low-waters periods. The results from Monte Castelo contrasts with the use of shell mounds as refuges from high-water season floods, a dominant hypothesis. A considerable shift in the nature of the fish spectrum occurred around 4000 BP with increased diversity; the number of taxa jumps from 18 to 48. The Middle Holocene occupations, from 6000 to 4000 BP, reflect long-term stability in drought-tolerant taxa collaborating with paleoecological evidence of dryer conditions. The post 4000 BP introduction of small-sized cichlids and characins suggests an initial exploitation of flooded forests. Archeological fish remains corroborate paleoenvironmental records of increased precipitation between the Middle and Late-Holocene. The probable replacement of some savanna areas by forest vegetation, and the accompanying alteration of aquatic landscapes, is documented through the presence/absence of certain taxa in Monte Castelo’s occupations. This suggests new economic strategies and the exploitation of new ecological niches, as the fish remains correspond to approximately 80% of the vertebrate fauna throughout the archeological sequence.

Download Full-text

Facing Change through Diversity: Resilience and Diversification of Plant Management Strategies during the Mid to Late Holocene Transition at the Monte Castelo Shellmound, SW Amazonia

Quaternary ◽

10.3390/quat4010008 ◽

2021 ◽

Vol 4 (1) ◽

pp. 8

Author(s):

Laura P. Furquim ◽

Jennifer Watling ◽

Lautaro M. Hilbert ◽

Myrtle P. Shock ◽

Gabriela Prestes-Carneiro ◽

...

Keyword(s):

Food Production ◽

Late Holocene ◽

Amazon Basin ◽

Management Practices ◽

Environmental Changes ◽

Production Systems ◽

Management Strategies ◽

Landscape Management ◽

Plant Management ◽

History Of

Recent advances in the archaeology of lowland South America are furthering our understanding of the Holocene development of plant cultivation and domestication, cultural niche construction, and relationships between environmental changes and cultural strategies of food production. This article offers new data on plant and landscape management and mobility in Southwestern Amazonia during a period of environmental change at the Middle to Late Holocene transition, based on archaeobotanical analysis of the Monte Castelo shellmound, occupied between 6000 and 650 yr BP and located in a modern, seasonally flooded savanna–forest mosaic. Through diachronic comparisons of carbonized plant remains, phytoliths, and starch grains, we construct an ecology of resource use and explore its implications for the long-term history of landscape formation, resource management practices, and mobility. We show how, despite important changes visible in the archaeological record of the shellmound during this period, there persisted an ancient, local, and resilient pattern of plant management which implies a degree of stability in both subsistence and settlement patterns over the last 6000 years. This pattern is characterized by management practices that relied on increasingly diversified, rather than intensive, food production systems. Our findings have important implications in debates regarding the history of settlement permanence, population growth, and carrying capacity in the Amazon basin.

Download Full-text

Did pre-Columbian populations of the Amazonian biome reach carrying capacity during the Late Holocene?

10.31235/osf.io/ws8et ◽

2020 ◽

Author(s):

Manuel Arroyo-Kalin ◽

Philip Riris

Keyword(s):

Carrying Capacity ◽

Human Population ◽

Late Holocene ◽

Amazon Basin ◽

Population Change ◽

Relative Population ◽

Robust Model ◽

Recent Developments ◽

Procurement Strategies ◽

Broad Region

The increasingly better-known archaeological record of the Amazon basin, the Orinoco basin, and the Guianas both questions the long-standing premise of a pristine tropical rainforest environment and also provides evidence for major biome-scale cultural and technological transitions prior to European colonisation. Associated changes in pre-Columbian human population size and density, however, are poorly known and often estimated on the basis of unreliable assumptions and guesswork. Drawing on recent developments in the aggregate analysis of large radiocarbon databases, here we present and examine different proxies for relative population change between 1050 BC and AD 1500 within this broad region. By using a robust model-testing approach, our analyses document that the growth of pre-Columbian human population over the 1,700 years prior to European colonisation adheres to a logistic model of demographic growth. This suggests that, at an aggregate level, these pre-Columbian populations had likely reached carrying capacity (however high) before the onset of European colonisation. Our analyses also demonstrate that this aggregate scenario shows considerable variability when projected geographically, which bears on our overall understanding of the resilience of past human food procurement strategies. Lastly, our results provide important insights into pre-Columbian demographic trends and offer novel perspectives on demic expansions, language diversification, and subsistence intensification in the Amazonian biome during the late Holocene.

Download Full-text

Disentangling late-Holocene climate and land use impacts on an Austrian alpine lake using seasonal temperature anomalies, ice-cover, sedimentology, and pollen tracers

Journal of Paleolimnology ◽

10.1007/s10933-007-9174-2 ◽

2007 ◽

Vol 40 (1) ◽

pp. 453-469 ◽

Cited By ~ 24

Author(s):

Roland Schmidt ◽

Monika Roth ◽

Richard Tessadri ◽

Kaarina Weckström

Keyword(s):

Land Use ◽

Late Holocene ◽

Ice Cover ◽

Alpine Lake ◽

Seasonal Temperature ◽

Land Use Impacts ◽

Holocene Climate ◽

Temperature Anomalies ◽

Pollen Tracers

Download Full-text

Sparse Radiocarbon Data Confound Culture-Climate Links in Late Pre-Columbian Amazonia

Quaternary ◽

10.3390/quat2040033 ◽

2019 ◽

Vol 2 (4) ◽

pp. 33

Author(s):

Philip Riris

Keyword(s):

Land Use ◽

Late Holocene ◽

Amazon Basin ◽

Mitigation Measures ◽

Land Use Patterns ◽

Climatological Data ◽

Use Patterns ◽

Archaeological Data ◽

Radiocarbon Data ◽

Intensive Land Use

It has recently been argued that pre-Columbian societies in the greater Amazon basin during the Late Holocene were subject to “adaptive cycling”. In this model, cultures practicing “intensive” land use practices, such as raised field agriculture, were vulnerable to perturbations in hydroclimate, whereas “extensive” land use patterns, such as polyculture agroforestry, are viewed as more resilient to climate change. On the basis of radiocarbon data, the relative rise and fall of late pre-Columbian cultures and their inferred patterns of land use in six regions are highlighted to exemplify this model. This paper re-examines the radiocarbon evidence marshalled in favour of adaptive cycling, demonstrating that alleged temporal patterning in these data are overwhelmingly likely due to a combination of sampling effects, lack of statistical controls, and unacknowledged uncertainties that are inherent to radiocarbon dating. The outcome of this combination of factors seriously limits the possibility of cross-referencing archaeological data with palaeo-ecological and -climatological data without controlling for these effects, undermining the central archaeological pillar in support of adaptive cycling in Amazonia. This paper illustrates examples of such mitigation measures and provides the code to replicate them. Suggestions for how to overcome the serious limitations identified in the Late Holocene radiocarbon record of Amazonia are presented in the context of ongoing debates on inferring climatic causation in archaeological and historical datasets.

Download Full-text