No. It was created by God.
The tribals living there may have learned how to drop seeds at different places and have slightly interfered with the trees distribution.
Discussion
I don't believe it was just a tribe; I think it was a fully functional, large civilization. We are starting to see evidence of this due to unfortunate deforestation of Amazon rainforest.
There is no unfortunate deforestation.
People who live there take trees down and replace them within the limits of their living grounds.
Some areas are exploited for raw materials by so-called friends countries.
The numbers are made up to look like the agricultural production is to blame.
Just like their private jets.
The mock of a civilization that happened to expand in parts of Amazon were the Aztecs and Maya. Not where we are at, though.
The former were wiped out after centuries of human sacrifices.