During the development of a tree, the lower limbs often die, but may remain attached for a time, sometimes years. Subsequent layers of growth of the attaching stem are no longer intimately joined with the dead limb, but are grown around it. Hence, dead branches produce knots which are not attached, and likely to drop out after the tree has been sawn into boards. COUNT 5
QSN1 What will the lower limbs of a tree usually do during development? ANS1 die QSN2 For what length of time can a dead lower limb stay attached to a tree? ANS2 years QSN3 Rather than being joined to the limb that died, where do subsequent layers grow? ANS3 around it QSN4 Are the knots that dead tree limbs form attached or not attached? ANS4 not attached QSN5 A detached knot will probably drop out of the wood when someone saws it into what? ANS5 boards