Brutal climate change, 8,200 years have caused a dramatic decline in the first South American crops

Sudden climatic changes, 8,000 years ago, could have caused widespread population declines in South America that lasted two millennia, according to scientists.

Archaeologists have shown that cross-precipitation has widespread repercussions throughout the region.

IThe indigenous South American population was booming before and after the sudden episode of climate change that saw abandoned sites across the continent.

The upturn about 6,000 years ago is evident, as local people have come up with new alternative farming strategies to cope with the natural environment.

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In a new study, archaeologists have examined data from sites in South America to try to understand the population trend in the region during the Middle Holocene (between 8,200 and 4 200 years).

The South American population has grown tremendously before and after about 2,000 years of decline, from 8,200 to 6,200 years ago.

By collecting data on nearly 1,400 sites in the region, 5,000 radiocarbon dates were taken and cross-referenced with climate data for the same period.

The University College London (UCL) study was the first to demonstrate the magnitude of population decline in South America during the first half of the Middle Holocene.

Significant changes in habits were observed during this period, when hunter-gatherer populations experimented with different domestic plants and formed new cultural habits adapted to the landscape and climate change.

Dr. Philip Riris of the Institute of Archeology of UCL and author of the latest study said: "Archaeologists working in South America have widely recognized that there are some 8 200 years ago, inhabited sites from various parts of the continent were suddenly abandoned.

& # 39;Unpredictable rainfall, especially in the tropics, appears to have had a negative impact on pre-Columbian populations up to 6,000 years ago, after which a recovery is evident.

& # 39; RReconversion appears to be consistent with cultural practices surrounding tropical plant management and early crops, possibly playing a buffer role when wild resources are less predictable. & # 39;

Mr. Riris added, "We have studied old rainfall data, such as marine sediments, to highlight exceptional weather events.

"Inside 100-year windows, we compared the average Holocene to prevailing patterns before and after 8,200 years.

"Normal precipitation suggests on average an exceptionally dry or humid year every 16 to 20 years, whereas under very variable conditions, this rate increases every 5 years or so.

"This puts into perspective the challenge that indigenous communities would have faced".

Dr. Manuel Arroyo-Kalin, co-author of the study, added: "Considered in the context of at least 14,000 years of human presence in South America, the events of the Middle Holocene are an element key to the cultural resilience of South American peoples and unexpected change.

He also explained that in the years preceding the population's decline 8,000 years ago, the size of the population has not been affected by climate change.

This may indicate that early Holocene populations had a social memory of sudden climate change from the previous transitional period that might have helped them develop effective strategies to cope with climate change.

The authors stated that the research provides a crucial historical context on how former indigenous populations of South America have addressed climate change.

The full report is published in Scientific Reports.