A team of ecologists and archaeologists from the State University of Mato Grosso in Brazil and the University of Exeter in the UK have discovered large amounts of abandoned dark lands in the Amazon Basin. The analysis showed that these were fields in which people applied fertilizers as early as 5,000 years ago.
The study is published in the journal Global Ecology and Biogeography and is briefly featured on the University of Exeter website. Scientists conducted a study aimed at identifying the role of ancient farmers in the formation of the modern landscape of the Amazon.
They drew attention to the fact that along the Amazon River there are many forest areas, which in their species composition differ significantly from the surrounding territories.
Scientists have found thousands of such sites, most of which were the size of a small field. They conducted excavations that showed that in these areas the topsoil, unlike relic forests, is very dark, almost black.
In addition, remains of charcoal and ceramics were found in these soil layers. These samples were studied in laboratories. Some of them are about 5,000 years old. Scientists also examined about 4,000 thousand trees that grow in dark lands and not far from them, on ordinary soil. It turned out that the dark lands are dominated by trees, the fruits of which can be eaten.
All this led the researchers to the conclusion that the dark lands were artificially created by man. Charcoal, ceramics and other fertilizers have been deliberately added to the soil for thousands of years. This contributed to the creation of a diverse ecosystem with a richer set of plant species.
Dark lands stretch for a thousand kilometers. It has not yet been established who created them, and when they were abandoned. The study proved that people have not used the dark lands for a very long time.
"By creating the dark land, the early Amazonians could successfully cultivate the soil for millennia," says Professor Jose Iriarte, an archaeologist at the University of Exeter. ".