Whether they were ignited intentionally or by accident, new research shows that the large forest fires the early hunter-gatherers started 20,000 years ago are the reason Europe is not more thickly forested today. The research has provided new insights into the role early humans played in the forming of the landscape.
Approximately 20,000 years ago, during the coldest part of the last Ice Age, it’s possible hunter-gatherers deliberately set forest fires in an attempt to create a landscape more attractive to the wild animals they hunted and easier to gather food and materials in. Additionally, less densely forested surroundings would have facilitated movement. However, the large-scale fires could just as easily have been caused by the hunters’ negligence.
Researchers analyzed accumulations of silt dating back to the Ice Age, along with computer simulations and new interpretations of existing archaeological data. The results show that early humans across Europe, between Spain and Russia, had the means to alter the landscape. This extensive impact by humans on the vegetation and the landscape would have happened over 20,000 years prior to the industrial revolution. The Ice Age is typically represented as being an extremely cold and snowy era ruled by bison, mammoths, and giant bears, but this research shows humans were just as capable of significantly impacting their surroundings.
This research also addresses why there have been so many differing reconstructions of this period. Reconstructions of vegetation from this era that were based on the plant and pollen remains from marshland and lakes indicate Europe was covered by an open steppe type of vegetation. However, computer simulations which were based on eight different possible climate conditions suggest the landscape in large regions of Europe would have been a lot more heavily forested under natural conditions This led researchers to conclude humans were the reason for this difference. Even more evidence supporting this conclusion has been discovered in the traces left from the fires used in hunter-gatherer settlements from this time period as well as in the ash layers found in the soil.
Being able to control fire was a turning point for early humans. It was a source of warmth and protection as well as a method for preparing food. Evidence for the first use of fire controlled by Homo erectus begins around 400,000 years ago. Evidence of the widespread use of fire by modern humans’ dates back to approximately 125,000 years ago.
An earlier report by Leiden’s Human Origins group had already proposed that Stone Age hunter-gatherers may have significantly modified their natural environment through the use of fire. This new research confirms the first hypothesis, and may also provide one of the earliest examples of this kind of large-scale impact by humans throughout all of Europe.
The research was funded by the European Research Council, the Swiss National Science Foundation and the European HERCULES research program. The findings have been published in the journal PLOS ONE.