The aim of the article was to study the growth of Douglas-fir plantations in the region of the Training Experimental Forest Enterprise, Yundola （Central South Bulgaria）. The study sites were three Douglas-fir planta...The aim of the article was to study the growth of Douglas-fir plantations in the region of the Training Experimental Forest Enterprise, Yundola （Central South Bulgaria）. The study sites were three Douglas-fir plantations, ranging between 50 and 55 years of age at altitudinal range between 1,400 m and 1,600 m above sea level （masl）. The mean height, diameter at breast height, site class, stem volume as well as the mechanical resistance （H/D ratio） of Douglas-fir were measured for each plantation. The results showed that Douglas-fir had the best height growth of the studied plantations on slope facing South at altitude 1,600 masl and Douglas-fir with age 55 years old reached a mean height of 32.4 m. The average diameter at breast height of the studied plantations reaches approximately 30 cm, which shows that they are suitable for large scale wood harvesting. The average stem volume of Douglas-fir in the observed plantations up to age of 55 is within the range of 400-600 m3/ha, with an average annual volume increment from 7 m3/ha to 12 m3/ha each year. The high index of mechanical resistance （H/D ratio） indicated a risk for abiotic damages, which implicated the need for the immediate implementation of felling.展开更多
The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through 100-degree-method the drying charact...The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through 100-degree-method the drying characteristic and basic drying condition were gotten, then drying schedule was developed for practical drying, the results showed that the drying schedule is suitable for Chinese fir and poplar plantation lumber, but shrinkage is large. The recommendation was made that enough dead weight is needed to decrease shrinkage in drying process. The drying quality of the two species of lumber is good in conventional drying method.展开更多
To use eucalyptus as solid wood products in value-added way instead of wood chips for pulp and paper, the sawing characteristics of E. grandis was studied, the strain changes in sawing process, bow deformation and end...To use eucalyptus as solid wood products in value-added way instead of wood chips for pulp and paper, the sawing characteristics of E. grandis was studied, the strain changes in sawing process, bow deformation and end-splits of lumber were analyzed. The results showed that the sawing strain changed in a random way, but the bow deformation had an evident regularity, the lumber near its bark had a big bow deformation. The end-splits had severe influence to lumber recovery, 15% of lumber recovery was influenced by end-splits. The results also indicated that planted E. grandis was a potential wood species as solid wood utilization in the fast-growing plantation.展开更多
文摘The aim of the article was to study the growth of Douglas-fir plantations in the region of the Training Experimental Forest Enterprise, Yundola （Central South Bulgaria）. The study sites were three Douglas-fir plantations, ranging between 50 and 55 years of age at altitudinal range between 1,400 m and 1,600 m above sea level （masl）. The mean height, diameter at breast height, site class, stem volume as well as the mechanical resistance （H/D ratio） of Douglas-fir were measured for each plantation. The results showed that Douglas-fir had the best height growth of the studied plantations on slope facing South at altitude 1,600 masl and Douglas-fir with age 55 years old reached a mean height of 32.4 m. The average diameter at breast height of the studied plantations reaches approximately 30 cm, which shows that they are suitable for large scale wood harvesting. The average stem volume of Douglas-fir in the observed plantations up to age of 55 is within the range of 400-600 m3/ha, with an average annual volume increment from 7 m3/ha to 12 m3/ha each year. The high index of mechanical resistance （H/D ratio） indicated a risk for abiotic damages, which implicated the need for the immediate implementation of felling.
文摘The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through 100-degree-method the drying characteristic and basic drying condition were gotten, then drying schedule was developed for practical drying, the results showed that the drying schedule is suitable for Chinese fir and poplar plantation lumber, but shrinkage is large. The recommendation was made that enough dead weight is needed to decrease shrinkage in drying process. The drying quality of the two species of lumber is good in conventional drying method.
基金This research is supported by ITTO Project PD 69/01 Rev.2 (I) "Improved and diversified use of tropical plantation timbers in China tosupplement diminishing supplies from natural forests".
文摘To use eucalyptus as solid wood products in value-added way instead of wood chips for pulp and paper, the sawing characteristics of E. grandis was studied, the strain changes in sawing process, bow deformation and end-splits of lumber were analyzed. The results showed that the sawing strain changed in a random way, but the bow deformation had an evident regularity, the lumber near its bark had a big bow deformation. The end-splits had severe influence to lumber recovery, 15% of lumber recovery was influenced by end-splits. The results also indicated that planted E. grandis was a potential wood species as solid wood utilization in the fast-growing plantation.
