The Microscopic Structure of Bark

The inner bark comprises the functioning phloem tissues and the innermost functional periderm. These tissues are all functionally important to the life of the stem, the phloem for the bidirectional conduction of synthesized food products, and 

Bark has very little meehanieal strength on aeeount of its lack of fibres. The bark of softwoods has no thiekened axially-elongated cells, but the bark of some hardwoods do sometimes eontain small numbers of short fibres similar to wood fibres. 

fats and fatty aeids, oils and resins are all readily extraeted from bark using non-polar solvents, while tannins, gums, peetin, soluble earbohydrates and sugars ean be removed by aqueous extraction. The amount of extraetives that ean be removed diminishes signifieantly after seasoning of the bark. 

The SEM photos in this chapter were taken by the author, Dr Li Guizhen, Dr Brian. Meylan and Professor Ilona Peszlen. 

BASIC WOOD CHEMISTRY AND CELL WALL ULTRASTRUCTURE 

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