[thinkingemote]

Think of a tree as a plant that comes from a seed. Plant 30 acorns, the forestry employees will weed out the other 29 over a few years. The ratio is probably higher if you start early, lower if you start with the type of 2 year old trees you can buy in a shop.

Outside of forestry, nature ensures that the majority of trees dont make it.

Another factor is that for fast growing trees used in pulp, they get felled in massive amounts every year. Planted trees are not left alone.