Sahara Fertlizing the Amazon?

[Cockybrit]

I have read it before, but they actually mentioned it during one of the 'Planet Earth' episodes on Sunday night.

 

So....does this argument hold water? Can the Saharan sands swept across the ocean really fertilize the Amazon?

 

If that is the case then why did the natives go through all the trouble to create Terra Preta?

 

Brad

[InfiniteNow]

I have read it before, but they actually mentioned it during one of the 'Planet Earth' episodes on Sunday night.

 

So....does this argument hold water? Can the Saharan sands swept across the ocean really fertilize the Amazon?

It would appear so. Remember, dust is not some single entity, but a large and vast collection of all types of different particles. For more information on the story, check out the following:

 

The Bodélé depression: a single spot in the Sahara that provides most of the mineral dust to the Amazon forest

About 40 million tons of dust are transported annually from the Sahara to the Amazon basin. Saharan dust has been proposed to be the main mineral source that fertilizes the Amazon basin, generating a dependence of the health and productivity of the rain forest on dust supply from the Sahara. Here we show that about half of the annual dust supply to the Amazon basin is emitted from a single source: the Bodélé depression located northeast of Lake Chad, approximately 0.5% of the size of the Amazon or 0.2% of the Sahara. Placed in a narrow path between two mountain chains that direct and accelerate the surface winds over the depression, the Bodélé emits dust on 40% of the winter days, averaging more than 0.7 million tons of dust per day.

 

 

If that is the case then why did the natives go through all the trouble to create Terra Preta?

Not sure I understand why this question is important. It sounds to me like you're asking, "If it rains, why do people water their lawns..." Or, "if we can eat our children, why do we go to the grocery store?" In other words, it comes across as sort of silly. :eek:

[Cedars]

I have read it before, but they actually mentioned it during one of the 'Planet Earth' episodes on Sunday night.

 

So....does this argument hold water? Can the Saharan sands swept across the ocean really fertilize the Amazon?

 

If that is the case then why did the natives go through all the trouble to create Terra Preta?

 

Brad

 

The sahara soil types are different than the brazilian soil types.

 

Trace amounts? Yes, but its doubtful (imo) that it really contributes to the 'fertility' due to the rainfall washing the tiny particles away before they can enter the soils below the organic layers.

 

The detail in the 6mb download is pretty amazing:

 

Global Soil Regions Map | NRCS Soils