You see, this is a propagandized knee jerk opinion. 

I'm not talking about monocrop eucalyptus. I'm talking within an agroforestry system as a biomass plug and growth stimulator. The goal of a great system should be to create it's own biomass, quickly, reducing or eliminating outside inputs. 

If native species can't fill that niche and haven't over time why be against non native species?

I also understand being a native species maxi but there's none or very little comparable fast growing emergent strata species. One can remove them from a system when your chosen climax species reaches the emergent strata. 

They've implemented these techniques using eucalyptus throughout Brazil and Central America.  

 It messes up all other trees and forestry around it. But you are saying to introduce in an area void of trees where they arent growing anyways? Thats not so bad i dont think since theres no other species to be destroyed by eucalyptus 

 Idk how you've concluded this, I work in native forests with introduced eucalyptus and they're bumpin.

Watch this shit  

And checkout the agroforestry folder in the link in my bio.

https://youtu.be/CQ6kabPXkb8