What is the concept a logger is using when he removes a particular fraction of trees on a job site in order to allow a certain amount of light to penetrate the forest floor for the younger trees?

Read the aphorisms. be slow in choosing a friend, slower in changing. an open foe may prove a curse; but a pretended friend is worse. a true friend is the best possession. according to these aphorisms from benjamin franklin's poor richard's almanack, what might happen if a person is careless in choosing a friend? it is best not to have friends because they will usually betray you. casual friends are often the best and can be more trusted than enemies. a person who has betrayed you can sometimes become a good friend. a friend who is not carefully chosen can be worse than an enemy.