L2

Question 1

Chemical compositions of wood

Answer 1

Cellulose

• 40%
• Units of glucose joining together forming linear long-chain polymer.

Hemicelluloses

• 30%
• Manufactured from 6-carbon and 5-carbon sugars
• Forming lower molecular weight polysaccharides
• Hemicellulose less organised

Lignin

• 27%
• Complex and high MW polymer.
• Functions like glue

Question 2

Woody biomass from forest harvesting

Answer 2

• Tree branches and leaves
• Tops (cutovers)
• Damaged and un-merchantable stems
• Stumps and roots
• Thinning

Handling

• collection
• transportation
• sizing
• drying
• densification

Question 3

Conventional system

Answer 3

• Manual felling and delimbing at stump

- Skidder extraction to log landing site

Question 4

Whole stem system

Answer 4

• Mechanical felling and delimbing at stump
• Skidder extraction to roadside for bucking
• Loading branches to trucks

Question 5

Tree pruning

Answer 5

• 5 years after planting, trees are pruned to height of 4m.
• 7 years, pruned to 6.5m
• Pruning produces a substantial yield of valuable knot-free wood in the lower part of the trunk