Question
could you explain to me what is windshake in trees and how to identify it

Answer
Wind shake is a crack or separation between growth rings in timber, attributed to the straining of tree trunks in high winds. It is a problem in limber when the tree is cut--the wood separates at the growth rings and can not be used for lumber. A standing tree shows very little effect that the wood inside has under gone wind shake. When the tree is cut the wood will usually shatter.