How are knots formed in trees?

Answer 1

Death or injury, infection, over-pruning and spurts describe why growing trees have knots. Death and injury produce loose knots whose centers are dead, as opposed to tight knots whose toughness indicates trunks spurting quickly at branched intersections. Excessive pruning and fungal infections respectively result in multi-shooted knots and in black knots on tinier branches and on twigs.

Answer 2

Knots are the bases of branches which have been covered as the tree has grown laterally. They may fit either tightly or loosely into the stem. If the branch was dead when the trunk grew around it, there tends not to be any connection between the xylem of the knot and the trunk and the knot fits loosely and may fall out of the wood, leaving a knot hole. If the knot was alive when the trunk grew around it, the xylem of the trunk and the branch are continuous and the knot fits tightly into the wood. Many knots may decrease the value of the timber. http://www.botany.uwc.ac.za/ecotree/trunk/woodanatomy2.htm

Answer 3

What is a knot on wood and trees? Is a knot the ame as a limb that didn't grow?