Having just read the study, it confirms pretty much what I expected - that defined ownership and regulated commercial exploitation are actually better for (this/the) environment than complete public ownership with no development (core protected area) or completely unregulated private development (the buffer area).

Many environmentalists are skeptical (to say the least) of the libertarian argument that ownership and commerce (private or communitarian) can actually be better for the environment than the "national park" model. When ownership and commerce are tied into protection, there are built-in economic reasons for stakeholders to manage the property correctly - owning deforested land is useless to a timber company. They will replant or try to offload that land - otherwise, it's a drain on their bottom line. And offloading the land is only good if the market value of the deforested land covers the cost of purchasing the land rights (minus forestry profits) in the first place. The tricky part is making sure they do it in an environmentally proper way, as opposed to moving to a monoculture of commercially useful species. That's where limited, focused regulation (like requiring FSC certification) comes in.

Deforestation was 20 times greater in the core protected area (no commercial activity) largely due to illegal logging, settlement and agriculture. Which is what you should expect - with no ownership other than the state, the economic incentive to use "free" land is enormous. As long as you can evade a small, overworked group of forest rangers, profit is enormous. Aside from national pride and the goodheartedness of the forestry types, no one (aside from flora and fauna) feels the injury. Owned land, in contrast, has people and companies that see illegal uses of "their" land as theft and immediately impactful of their bottom lines. They will hire private security and force prosecutors and law enforcement to deal with thieves. "Free" land, however, is always tempting - to dishonest companies, to desperately poor people and to politicians tempted to profit from using "just this little piece" for private industry that gets the use of the land and can then walk away from the results.

Similar issues arise with the wildfire issue - owners will do what's needed to prevent losses due to fire and can build that into their profit models. Doing the same to the core protected areas is purely a cost to government, and must compete with thousands of other demands to the public purse.

I'm no expert when it comes to rainforests, but I know that in prairies and boreal forests that fire is a good thing, and certain species are dependent on wildfires to thrive. So isn't considering a lack of wildfires a troublesome way of confirming healthier forest ecosystems?

Here in Oregon, we manage our forests to mimic fires in order to prevent them. We cut down smaller shrubs and pile up ground vegetation, and burn it, leaving the ash and coals to populate the soil as if a fire came through. This is due to the fact that "protecting" the forests from fire actually puts them at great risk of burning out of control by allowing huge amounts of tinder-like fuel to build up. All that burning fuel on the ground that has built up for years or decades spreads like, well, wildfire. In fact, a dense forest is not healthy (in our eco-system). It allows one or few species, which are usually controlled by fire, to take over and block out everything else.