Lecture 01 - SW

• Genetically determined

• Climatic factors

• Mechanical loads

• Hormones, Gravitation

• 90% Axially oriented tracheids

  • earlywood tracheids with thin cell walls (water transport)

  • latewood tracheids with thick cell walls (mechanical stable)

• 10% Parenchyma cells

  • predominatly in rays

  • storage

  • surrounding resin channels

  • heartwood formation, pathogen defence

= half borded pits

can be seen in Wood ray (radial)

• a: Pits window like

• b: pits pinoid

• c: piceoid

• d: cupressoid

• e: taxodioid