2023-09-20 マサチューセッツ工科大学(MIT)
◆MIT、フロリダ大学、ブラジルの研究者からなるチームは、この問題を解決しました。彼らは黒土の起源を明らかにし、古代アマゾン人が土壌改善のために黒土を意図的に作成し、大規模な社会を支える手段として使用していたことを示しました。さらに、黒土は大量の炭素を含んでおり、気候変動緩和のための新たな方法の示唆源となる可能性があります。
◆現代の先住民コミュニティも同様の土壌改善方法を実践しており、古代の知恵を現代の課題に応用できる可能性があります。
＜関連情報＞
- https://news.mit.edu/2023/ancient-amazonians-intentionally-created-fertile-dark-earth-0920
- https://www.science.org/doi/full/10.1126/sciadv.adh8499
アマゾンで炭素が豊富な黒土の土壌を意図的に作り出した Intentional creation of carbon-rich dark earth soils in the Amazon
Morgan J. Schmidt,Samuel L. Goldberg,Michael Heckenberger,Carlos Fausto,Bruna Franchetto,Jennifer Watling,Helena Lima,Bruno Moraes,Wetherbee B. Dorshow,Joshua Toney,Yamalui Kuikuro,Kumessi Waura,Huke Kuikuro,Taku Wate Kuikuro,Takumã Kuikuro,Yahila Kuikuro,Afukaka Kuikuro,Wenceslau Teixeira,Bruna Rocha,Vinicius Honorato,Hugo Tavares,Marcos Magalhães,Carlos Augusto Barbosa,João Aires da Fonseca,Kelton Mendes,Luís Reynaldo Ferracciú Alleoni,Carlos Eduardo Pellegrino Cerri,Manuel Arroyo-Kalin,Eduardo Neves, and J. Taylor Perron
Science Advances Published:20 Sep 2023
DOI:https://doi.org/10.1126/sciadv.adh8499
Abstract
Fertile soil known as Amazonian dark earth is central to the debate over the size and ecological impact of ancient human populations in the Amazon. Dark earth is typically associated with human occupation, but it is uncertain whether it was created intentionally. Dark earth may also be a substantial carbon sink, but its spatial extent and carbon inventory are unknown. We demonstrate spatial and compositional similarities between ancient and modern dark earth and document modern Indigenous practices that enrich soil, which we use to propose a model for the formation of ancient dark earth. This comparison suggests that ancient Amazonians managed soil to improve fertility and increase crop productivity. These practices also sequestered and stored carbon in the soil for centuries, and we show that some ancient sites contain as much carbon as the above-ground rainforest biomass. Our results demonstrate the intentional creation of dark earth and highlight the value of Indigenous knowledge for sustainable rainforest management.
