Even living things obey the laws of physics without exception, and physics says that a branch will have an equal amount of both tension and compression FORCE at any particular cross section. Now, the wood may not be able to bear as much tensile STRESS (not the same thing as force) as compression; this would mean that greater than half the cross-sectional area is in tension and less than half in compression (and the point of zero stress would be below the center). Average tensile stress would be lower than average compressive stress, but since there would be proportionately more area under tension than under compression, the magnitudes of the tensile and compressive FORCES are equal.
-- My broker promised me he would treat my money as if it were his own. Trouble is, he did.
