GRISLEY
You son looks like a fun filled guy.
Part of what is being said seems to me to relate to the purpose of your picture.
ACTIVITY KEEPSAKE:
***************
If the idea is to have a keepsake of this tree climbing activity at a young age, then this is fine composition -- although weather and time of day might have been chosen to give you more dramatic lighting....at the risk of complicating sun/camera direction and the possible need for fill in flash to avoid facial shadows.
OUTDOOR PORTRAIT
***************
If the idea was to have more of an outdoor portrait of your son, then you must get closer -- with or without the tree as a prop. To explore this portrait approach , simply search for child/son/portrait on this site. You will see many fine posts by Mitch, onehotrx7, and many others of kids in a closer portrait setting. As well, experts such as Eland offer insight on the realted photos.
Along the above lines my best (I thought) early portrait was a lot like yours although it only included about 1/4 of your frame. It was reviewed by my camera club years ago. I got slammed! The universal advice was for me to move in on the face. But note that once you move in, you will have to shoot with the zoom fairly full. Otherwise you will be too close to your son and the facial "geometry" will be distorted!
He looks like a typical, wonderful and happy guy.Close-up please.
HOWIE