There is a controversy in the field of nature conservation which boils down to 'what amount (& other specifics) of human intervention can be allowed in a habitat, such that it is still considered 'wild'?'. The question can sometimes be viewed as a set of 'decision - human intervention - outcome - monitoring', and this is a practical approach with classifiable results, BUT it is only applicable to certain types of habitats, usually (in Continental Europe, I think) already quite anthropogenically transformed. (There are other restrictions, too.) So when you have to decide for any particular patch of 'wilderness' the best way to preserve it, you side with the experts who say 'touch nothing and let only Nature rule there', and the number of species in that place goes down (because there is not enough large mammals, etc.) OR you side with those who say 'traditional land use!' In this case, you get a nice, heterogeneous reserve and a positive feedback loop that will eat it sooner or later. Damned if you do, damned if you don't.

I try not to pick sides, unless I know the habitat well, but whatever I do, I seem to lose.