The complete blackness was put there intentionally to hide some issues with plant appearance close to the camera in my original render. Anything less than solid black just wasn't working for me at the time during post work.
The black is not hurting it one bit, though. I just wanted to make sure I wasn't missing any details. You've crated an enchanting world and a very inviting image showing it off - makes one want to go get that boat and start exploring .