Abstract:
The mean fiber length of three beech trees (Fagus orientalis L.) at the lower and higher
points (1% and 75% tree height) of the stem at an intermediate altitude (500-1000m) in
the Caspian forests in Sari region were 1.36 and 1.22mm respectively, close to the values
in three trees at high altitude (1000-1500m), that were found to be 1.39 and 1.36 mm. The
mean fiber lengths of the whole stem, using stem formula, were considered as 1.31 and
1.38mm at intermediate and high altitudes and so were very close each other. Juvenile
wood portions in the stem comprised 17 annual rings, which took up 7.3% of the stem by
volume at intermediate altitude. At high altitude, these values were obtained as 18 annual
growth rings, and 8.75% juvenile wood in the stem. The reason for greater juvenile wood
at high altitude was somehow a wider ring width at higher elevation. The mean ring width
of lower and upper points of the stem at intermediate altitude were found to be 1.82 and
2.95mm respectively; meanwhile, at high altitude, the findings were 2.97, 3.37mm. Despite
the data obtained, t- test comparison was conducted between mean fiber lengths of the
two heights of the stems at two altitudes, and no significant differences were found at the
1% level. The exploitation age was strongly dependent on how much juvenile wood there
was in the stems, that at high altitude was greater than at intermediate. However, statistical
comparison showed no significant differences between that and the 1% level. Therefore,
altitude in the range of about 500m showed no important impact on beech fiber
length, exploitation age or juvenile wood border in Caspian forests.
