E. Baucker et al., WOOD PROPERTIES OF HEAVILY POLLUTION-DAMA GED SPRUCE (PICEA-ABIES [L]KARST) IN THE HIGH-ALTITUDE ZONES OF THE EASTERN PARTS OF ERZ-GEBIRGE, Holz als Roh- und Werkstoff, 54(4), 1996, pp. 251-258
The question for the wood properties of the tree species in regard to
its further worthiness of cultivation and silvicultural treatment has
been raised within the framework of the joint project ''Investigations
of Forest-Ecosystems in Erz Gebirge as a basis of a Forest Reconstruc
tion by Ecological Criteria'' undertaken within the framework of the B
undesministerium fur Bildung, Wissenschaft, Forschung und Technologie
(BMBF) (Federal Ministry of Education, Research, and Technology). A de
crease of tracheid lengths as well as of the lumina of early wood has
been ascertained in sapwood annual rings smaller than 0.5 mm in width
of mature spruce, the wood of which having been subject to heavy damag
e due to SO2 pollution. The late wood was characterized by decreasing
cell wall thickness and larger microfibril angles within the cell wall
layer S-2. The anatomical and structural features of wood distinguish
ed by narrow annual rings have been found both in heavily pollution-da
maged trees as well as in trees with comparably narrow annual rings of
non-polluted sites. Strength investigations in terms of materials tes
ting according to DIN yielded normal strength values of wood that was
not affected by secondary agents. Investigations on particularly small
test specimens (Dynstat examinations) up to a minimal annual ring wid
th confirm the known relationships between wood density and impact ben
ding strength. Thus, the wood of spruces growing in the high-altitude
belts of the eastern parts of Erz Gebirge may be used without reservat
ions.