On an epic voyage, dust from a single valley in Africa takes a 5000km flight across the globe, only to land in the Amazon. It’s not just any old dust. It’s rich in iron and phosphorous, which are essential for fertilizing plants...
and it weighs a total of 50 MILLION TONS.
For anyone that has visited the Amazon and looked down, you’d be quick to note that below the thin layer of dead leaves is reddish/orange clay- pretty terrible for growing plants. However, plants here have adapted in various ways- most significantly through shallow, wide roots that can absorb nutrients in the upper layers of the soil- to take advantage of any minerals and nutrients they may come across.
It was long thought that the most significant source of any minerals that did feed the Amazon rainforest were from the rivers which are full of all sorts of nutrients from the upland volcanic Andes they start in. When flooding occurs, the plants rejoice- sandy deposits layer the earth and provide an essential source of minerals needed for growth.
However, this new study, published here, shows that a huge source of the minerals that keep the Amazon thriving come from the continent next door, Africa. Incredibly, dust storms take up thousands of tons of dust every day from a dry, salty river bed and blast across the Atlantic Ocean to end up in the Amazon. The millions of tons per year that are deposited are likely to be found to be incredibly important, it can account for plant growth in areas that otherwise have little access to the mineral-rich rivers.
So, much thanks to one small valley in Africa, the Amazon blooms.