Just my dos colones (a colone is worth about 1/4 of a penny)
In any industry, there are people who take a road that is less traveled, sometimes it heads to a dump, but othertimes it perhaps leads to a new paradigm.
It is my opinion that the mono-cropping is here to stay - just like cattle replaced wild animals in the forest being used for food. I don't see that going away quickly either. Not with the level of population in the world. There are tree species that do well mono-cropping and are in high demand - and they probably will always be grown that way.
There are serious issues that face mono-cropping - but substitute cows for trees and you will see that often they have been dealt with in the past. It requires more focus to mono-crop than to have a natural forest, but usually it is more profitable.
We are using mono-crop techniques for the first phase of the plantation, then shifting to a perpetual forest. The first phase produces a "crop" that pays off the land, the second phase is for sustainability. Besides, I think many of the trees that are not grown in plantation will be much more valuable in the future - just like buffalo is more expensive than beef.
Besides, I like rainforests and I have the pleasure of creating a system where I can have my forest, and my lumber too.
About half of our plantation is mixed with wild areas separating the mono-crops.
One of the things if you are looking at getting into Farm Forestry to remmeber is that when all you have is a hammer - everything looks like a nail. The people who I know who are doing well are very well read - they don't just throw trees in the ground, but they are starting small and running experiments. Then, when they know what they are doing, they go full scale. There is no need to be in a hurry, and remember that your first few years will setup how much money you will make in the future.
Fred
P.S. I found the article very interesting.