If you look at great images, your eye seems to go to certain items. Usually, they are placed in so called ‘power points’. Imagine a tic-tac-toe grid, dividing the image both horizontally and vertically into thirds. he ‘power points’ are the four places where the lines intersect.
You do not want to place the horizon line of your image in the middle, rather at 1/3rd or 2/3rds. The decision of where depends on what you want to emphasize. If the sky is the ‘main attraction’, the horizon line would be at about 1/3rd of the height. (example: ‘Cape of Good Hope’) In the image of the Lynx, the eyes are at about 2/3rds. If they would be at 1/2, the image would not have the same impact.
A lone tree in a meadow is best placed in one of the ‘power points’. If the tree is in the foreground though,, it is my experience that it makes the entry into the image more difficult. I wonder if it has to do with the fact, that in our culture, we read from left to right and so the eyes move in that direction. Judge for yourself by looking at the image with the tree. Let me know what you think.
As a last point: rules are there to be broken, though one needs to understand the rule before one can break it 🙂 With landscapes, look, move around and then decide what works for you.