Hygrading is the slow destruction of a forest via removing the higher quality trees and leaving the poorest quality trees.
Hygrading is one of the main forest ailments that foresters fight against.
Hygrading is often the result of well-meaning landowners and loggers who go with the old fashioned idea of cutting the big trees and letting the smaller trees grow a while longer.
Some loggers go so far as to set up contracts with landowners allowing them to take all trees over a certain diameter while leaving all of the smaller trees.
The problem with the "leave the smaller trees to grow” logic is that often times the smaller trees are the same age as the larger trees, they are just defective trees.
By leaving these defective trees and removing the best trees in the forest it degrades the genetic seed source of the forest with each thinning.
While nearby industrial forests, and some government forests that are being supervised by a forester, are growing extremely high quality trees.
The main difference is that in the Managed Forests, a Forester is marking the poorest trees in every harvest and leaving the best trees to regenerate.
By managing these forests properly they will continue to grow better, healthier trees with each thinning.
If you are considering thinning your forest, step one, HIRE A FORESTER!
And NEVER let anyone talk you into Hygrading your forest.