The Effect of Altitude on Juvenile Wood Formation and Fiber Length, a Case Study in Iranian Beech wood (Fagus orientalis L.)

The mean fiber length of three beech trees (Fagus orientalis L.) at the lower and higher points (۱% and ۷۵% tree height) of the stem at an intermediate altitude (۵۰۰-۱۰۰۰m) in the Caspian forests in Sari region were ۱.۳۶ and ۱.۲۲mm respectively, close to the values in three trees at high altitude (۱۰۰۰-۱۵۰۰m), that were found to be ۱.۳۹ and ۱.۳۶ mm. The mean fiber lengths of the whole stem, using stem formula, were considered as ۱.۳۱ and ۱.۳۸mm at intermediate and high altitudes and so were very close each other. Juvenile wood portions in the stem comprised ۱۷ annual rings, which took up ۷.۳% of the stem by volume at intermediate altitude. At high altitude, these values were obtained as ۱۸ annual growth rings, and ۸.۷۵% 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 ۱.۸۲ and ۲.۹۵mm respectively; meanwhile, at high altitude, the findings were ۲.۹۷, ۳.۳۷mm. 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 ۱% 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, statisti-cal comparison showed no significant differences between that and the ۱% level. There-fore, altitude in the range of about ۵۰۰m showed no important impact on beech fiber length, exploitation age or juvenile wood border in Caspian forests.

Keywords:

Beech , Exploitation age , High altitude , Intermediate altitude , Juvenile wood , Mature wood , Papermaking , Wood fiber