Wood defects

Formed when cambium is locally killed by forest fire

Callus: unorganized tissue consisting of amorpphous mass of lossley arranged thin-waööed parenchymatous cells

Forms around negrotic tissue

Normal tree rings that overgrow the scar

High abundance of traumatic resin ducts around the scar

locally kill cambium bby mechanical impact

Callus tissue forms around the wound

Wood below the wound can become discoloured and compression wood can form on the other siede of the stem

Tangetial bands of traiatic resin ducts are abundant close to wound tissue

shrunken/reduced earlywoood vessels

anomalous latewood

disrupted parenchyma

little fiber

collapsed sickle shaped earlywood vessels in submerged parts

Periodically thin rings with narrow and less dark latewood

Reduced CWT in outbreak years

Recovery of CWT takes several years

Hyphae of fungi infect the sapwood of living and dead trees

Causing dark-blue discolorisation

Blue stain fungi interfere with water and nutrient transport and also feed on sugar, proteins and starch in the wood

Ophiostoma sp.

Hymenoscyphus fraxineus

Narrower rings with narrower latewood and smaller earlywood vessels in infested trees

conceptual framework to describe how trees respond to injury of damage, particularly in realtion to decay caused by pathogens or other factors

Trees form a barrier zone of specialized cells to separate the healty and damaged tissue

Barrier zone surrounded by a reaction zone biochemical and physiological reactions to defend against decay organisms

Genertical defect of norway spruces

Valuable soundwood