"Forest restoration is an inclusive process, which depends on collaboration among a wide range of stakeholders including local communities, government officials, non-government organizations, scientists and funding agencies."
> They found that soil fertility takes less than 10 years to recover to old-growth forest values. Plant functioning takes less than 25 years, and species diversity takes 60 years. Above-ground biomass and species composition take over 120 years.
This is also discounting any of the unique biodiversity in the Amazon, of which there is a lot and may never come back.
[1]: https://news.clemson.edu/researchers-if-left-alone-tropical-...
After getting rid of the gross weeds, it only took a couple of years for a bunch of native rainforest species to start popping up, but it's going to be a very long time before what they call "ecosystem function" is approximately back to the way it was before. You can reduce this time in the tropics because the carbon cycle is so fast, but it's still going to take many years of restoration. Appropriate management can speed things up, but only so much - and the techniques used vary in effectiveness.
Temperate forest soil has a lot more capacity for regeneration, but we're 3-4 rounds of clearcutting into most North American forests and we are hearing alarm bells about how there might not be another round if we don't change something.
The Supposedly Pristine, Untouched Amazon Rainforest Was Actually Shaped By Humans
https://www.smithsonianmag.com/science-nature/pristine-untou...
This is incorrect. The Amazon was cultivated by native communities
And remember, that Amazonian rain forest can't just be restored by planting a bunch of trees. If restoration is at all possible, it requires carefully planned intervention of decreasing intensity over a prolonged period of time. See:
https://en.wikipedia.org/wiki/Forest_restoration
for a bit more on this.