Okay...
Dino World
Pretty simple but good. I'd suggest you to add something else there, so there wouldn't be just trees.
Also greens circle of fail detected and those black trees fails too, fix 'em

It's gonna be pretty good terrain.
Lake
Add tree varitation, there is only one kind of trees, and they are all same sized...
Area behind lake looks damn empty, add rocks and shrubs there. And as said it looks very artificial. I guess that tree varitation and rocks+shrubs behind lake will do something.
Water is made pretty good, that transparent effect looks good but what the heck are those corals doing there? Those doesn't look natural at all with all of those colors.
Forest
Not much to say, some shrub, trees and couple rocks... and fog.
It's looks bit... meh.
Add something special there, custom trees and that kind of stuff.
Mountain road
It got same problems as Forest pic.
Magic Hunter House
It's flat, add height varitation and forest needs tile varitation.
And again, why there is only one kind of trees what are all same scale. And forest need more stuff... there is only trees, add rocks, shrubs and other kind of stuff.
So these are my suggestions and my thoughts. I hope you will read 'em carefully and think about 'em.