Compression Wood vs. Tension Wood
- Compression wood
- Tension wood
Key Differences
What is Compression Wood?
Compression wood is usually formed in conifers on the lower side of the trunk. Wood with high lignin content is compression wood and that is why it is strong in compression. In conifers, compression wood is formed on the underside of its branches. As it is rich in lignin, one of its function is to prevent the branch from drooping. Pith is not present in the center but way above the center point, which indicated much more development on the top. In cross section, these branches form an oval shape. If compression wood would not have been formed then progressive bending and cracking would have occurred in the branches. Compression wood is usually formed on that side of the branch which bears the most pressure. It thereby helps in lengthening and straightening the bend. It has only 30% of cellulose. It helps in maintaining the angle of bending, providing more strength. Precisely, it is a a blessing.
What is Tension Wood?
Tension wood is usually formed in dicots on the upper side of the trunk which is leaning or bent. Tension wood contains more cellulose than compression wood therefore it is very strong in tension and can easily resist leaning or bending. Hardwoods like oaks form tension wood in them on the upper side of the branch. It prevents the branch from drooping or bending, they switch to develop more wood on the underside which is called normal wood. It is usually formed on the part of the plant which is under tension, pulling it towards the affecting force. It has higher amount of cellulose than normal wood, around 60%.
