It consists on theassociation of a fungus with the roots of a higher plant, it can be done naturally or it can be done artificially, this process will lead to a better reforestation.
Mycorrhization is closely related to the species and the age of the plant, so that the fungi that associate with the young plant are called primary or pioneer, while those that already associate with the adult plant are called "Late Stage" fungi, thus there is a true mycological succession.
The late ones can be associated with young trees but they will only produce fungi when the trees reach their adult stage (around 6-12 years of age, depending on the species and site conditions).