A recent article in Environmental Research Letters studies this interesting phenomenon. As Richard Fisher at New Scientist reports,
The trees and plants in the Amazon rainforest rely on nutrient-rich dust from a single valley in the Sahara desert for sustenance, researchers have discovered.
Scientists know that millions of tonnes of mineral dust are blown from the Sahara desert to the Amazon basin each year. The dust helps keep the Brazilian rainforest soils fertile.
(continue reading at New Scientist)