Abstract:

Statistically distinct differences in 10 year old tree growth increments, percent of late wood, tracheid morphological features (tracheid length, tracheid width, tracheid diameter, tracheid double wall thickness, tracheid length width ratio, tracheid double wall thicknessdiameter ratio and tracheid diameter width ratio), microfibril angle(MFA) in secondary layers of tracheid walls and basic density were found among 31 provenances for exotic Loblolly Pine (Pinus taeda) grown in Forest Farm of Fuyang County in Zhejiang Province of China. There were no significant differences in cellulose and lignin contents among 10 provenances except pentosan and benzene alcohol extractives. The wood properties above except chemical composition were genetically controlled in medium or higher level and their broad sense heritability (h 2 f) were greater than 0.50 The h 2 f of wood chemical contents were 0.088 in cellulose, 0.003 in lignin, 0.340 in pentosan and 0.307 in extractives. The planting environment had also large significant effects on these wood properties above. The latitude of provenances in indigenous regions was negatively correlated with the trees growth increments, tracheid width, tracheid diameter and MFA, and positively with latewood percentage, basic density. The diameters at the breast height of the trees were notable negatively related to basic density, tracheid lengthwidth ratio, tracheid double wall thicknessdiameter ratio and positively to tracheid width, tracheid diameter and tracheid diameterwidth ratio.

Key words: Pinus taeda, wood properties, provenance, genetic variation and improvement, growth rate, pulpwood, exotic