Indian Black Earth And Biodiversity Of The Amazon – New Study

Conny Waters - AncientPages.com - Amazonian peoples who inhabited the region between 2,000 and 8,000 years ago left a legacy that today gives sustainable agriculture, the preservation of biodiversity It also gives the possibility to the survival of river-dwelling communities.

Their legacy included a soil known as terra preta de índio –Indian black earth. Early inhabitants of the Amazon region fertilized the soil with charcoal from fire remains and food waste, according to a new study.

Their innovations improved soil fertility, which continuously has an impact on the biodiversity of the region because black earth is rich in calcium, magnesium, zinc, manganese, phosphorus and carbon, which make for a fertile mix.

This is a rare quality in the Amazon, where acidic soils are normally not well-suited for crop cultivation.

“This is an area where dark earth lush forests grow, with colossal trees of different species from the surrounding forest, with more edible fruit trees, such as taperebá and jatobá,” lead author Dr. Edmar Almeida de Oliveira said in a press release.

The study - to measure the difference in vegetation in dark and non-dark earth areas - focused on abandoned areas along the main stem of the Amazon River near Tapajós and in the headwaters of the Xingu River Basin in southern Amazonia.

Researchers from the State University of Mato Grosso in Brazil and the University of Exeter sampled around 4,000 trees in southern and eastern Amazonia. Areas with dark earth had a significantly higher pH and more nutrients that improved soil fertility. Pottery shards and other artifacts were also found in the rich dark soils.

Photo: Bruno Kelly. source

The team has found areas with this “dark earth” that have a different set of species than the surrounding landscape, contributing to a more diverse ecosystem with a richer collection of plant species.

These findings show the small-scale long-term legacy of pre-Columbian inhabitants on the soils and vegetation of Amazonia.

The legacy of this land management thousands of years ago means there are thousands of these patches of dark earth dotted around the region, most around the size of a small field.

The number of indigenous communities living in the Amazon collapsed following the European colonization of the region, meaning many dark earth areas were abandoned.

The study reveals for the first time the extent to which pre-Columbian Amerindians influenced the current structure and diversity of the Amazon forest of the areas they once farmed.

“Pre-Columbian indigenous people, who fertilized the poor soils of the Amazon for at least 5,000 years, have left an impressive legacy, creating the dark earth, or Terras Pretas de Índio,” Professor Ben Hur Marimon Junior, from the State University of Mato Grosso, said.

Professor José Iriarte, an archaeologist from the University of Exeter, said: “By creating dark earth early inhabitants of the Amazon were able to successfully cultivate the soil for thousands of years in an agroforestry system

“We think ancient communities used dark earth areas to grow crops to eat and adjacent forests without dark earth for agroforestry.”

Dr. Ted Feldpausch, from the University of Exeter, who co-authored the study with Dr. Luiz Aragão from the National Institute for Space Research (INPE) in Brazil, also added that “after being abandoned for hundreds of years, we still find a fingerprint of the ancient land-use in the forests today as a legacy of the pre-Colombian Amazonian population estimated in millions of inhabitants.

“We are currently expanding this research across the whole Amazon Basin under a project funded by the UK Natural Environment Research Council (NERC) to evaluate whether historical fire also affected the forest areas distant from the anthropogenic dark earths”.

Many areas with dark earth are currently cultivated by local and indigenous populations, who have had great success with their food crops. But most are still hidden in the native forest, contributing to increased tree size, carbon stock, and regional biodiversity.

Research

Written by Conny Waters - AncientPages.com Staff Writer