Abstract:

Thirty three trees from a seventeen years old plantation of Chinese tulip tree (Liriodendron chinense) in Fenyi county, Jiangxi Province were randomly selected, and their basic density, and fiber length of each growth ring for the increment core samples at breast height were measured. The results showed that the radial pattern appeared a “V” type curve for basic density and an exponential one for fiber length. Age-age correlation analysis showed the earlier selection for basic density and fiber length was at a cambial age not younger than 5 at the breast height. Compared with provenance trials with 15 sevenyears old provenances, analysis results showed that the radial pattern curves were basically parallel for both seven-year-old and seventeen-year-old plantations, and indicated the earlier selection was also applicable(α=0.05) for the provenance trials. Finally, the variation trend of mean age-age correlation coefficients (MACC) with age interval was discussed. MACC of both basic density and fiber length in L. chinense decreased with the increase of age interval value although the decreasing rate of basic density was more violent. According to the MACC analysis, the result also suggested that it was feasible for earlier selection of the two main wood characteristics, but earlier selection would be more reliable when the plantation age is older than seven years old in practice.

Key words: Liriodendron chinense, Basic density, Fiber length, Radial variation pattern, Earlier selection, Mean age-age correlation coefficient, Age interval