the idea that he has little interest in policy and in the details of management is abundantly supported. if his vice president would not be the effective president, then someone else (or multiple someones) certainly would be. that's not to say that he wouldn't wander around randomly overriding his staff and colleagues at inopportune times.
to refocus the discussion, there's no evidence that trump has any particular interest in public lands policy, so the idea that he'd pay attention to that particular arena is far-fetched at best.