I absolutely love this tree. I bought it as this clump and thought 4 would be ok. The more see it grow the more I'm concerned about the tree circled. Not only is it growing around the other tree but it's also the most upright of the 4 and I'm worried that it'll crowd out the others.

The tree is 7 is years old if I had to guess. The tallest of the 4 is probably fifteen feet high the others are a good 12ish feet.

Would cutting out the circled tree put the others at risk? I'm sure the sooner the better if so. Or should I not worry about it and let it sort itself out? Will they start to naturally grow apart from each other?

Any info is greatly appreciated.

Also, the species is Himalayan Birch (Jaquemontii)