Variations of paper pulpwood properties within individual of new Aigeiros clones of southern type

Key words: 
• Populus /
• clone /
• wood property /
• specific gravity (basic volumetric mass) /
• fiber properties /
• frequency distribution /
• Aigeiros

Abstract: A systematic study made in a clonal test forest in Linhai on timber properties of paper pulpwood of 20 new aigeiros clones of southern type shows that the fiber length in the trunk of these new clones gradually increases from the top to bottom , the fiber of the branches in the upper part of the canopy being shorter than that of the branches in the middle or lower part of the canopy ;the specific gravity in the lower part of the trunk is high as compared with that in the upper part , the latter being slightly higher than that in the middle part ;and the specific gravity is the smallest for the branches in the lower part of the crown , which gradually increases upwards .The frequency of the wood fiber length in different parts of the trunk is in evenly normal distribution .The difference in average values of the fiber length of the trunk is mainly reflected by the difference in the quantity of the fiber that is either shorter than 0.7 mm , a mid-value of classes , or longer than 1.3 mm .For the trunk of the 20 clones , the fiber length is between 0.940 0 and 1.005 9 mm , which meets the standard laid down by the International Timber Society for the fiber of middle rank and the specific gravity ranges from 0.333 3 to 0.346 7 gcm-3 in different parts .For branches , the fiber length changes from 0.6861 to 0.725 2 mm and the specific gravity from 0.358 8 to 0.368 8 gcm-3 .Finally , some constructive suggestions on tending and utilization of these new clones as a kind of paper pulpwood are put forward .