Study On Wood Property Variation Of Chinese Fir Clones

Chinese fir is one of the fast-growing trees providing with wood in south China. With the materials from the fourth group clones of Yangkou Forest Farm in Fujang province, Chinese fir growth and wood property characteristics were studied within clones and among clones respectively by measuring basic density, early wood microfibril angle, tracheid lenghth and width to reveal growth or characteristics variation law and provide some basic theory and scientific foundation for directional developing and wood processing. The research showed that:(1) Annual ring width decreased gradually, basic density within annual ring played a law from big to small and again to big since 7th annual ring and the basic density of the last annual ring was obviously bigger than others from pith to bark. The regular pattern of microfibril angle from pith to bark was a "wave" and decreasing-trend curve, but its trend was not obvious. Tracheid length, width and ratio of length to width increased with the increase of ages.(2) Every property characteristic in the tenth annual ring had positively significant correlation with the value in single trees. It showed that it was reliable to evaluate and predict the wood property with the value of the tenth annual ring.(3) The correlations of every characteristic between annual rings were significant mostly in a next annual ring, especially in density, tracheid length and width between the comparatively broad annual rings. It showed that those characteristics become stable earlier than other characteristics.The correlations regularity of early microfibril tracheid ratio of length to width were insignificant between annual rings.(4) The correlation between density and microfibril angle or between density and tracheid characteristic or between microfibril angle and tracheid characteristic in the tenth annual ring were insignificant; Early wood tracheid length and ratio of length to width, length and width, late wood trachied length and width, length and ratio of length to width showed positively significant correlation in tracheid characteristics in the tenth annual ring, early wood tracheid width and ratio of length to width, late wood tracheid width and ratio of length to width showed negatively significant correlation,but other tracheid characteristics were insignificant correlation There are substantice genesis in the traits of insignificant correlation,they may be selected respectively, or they must be considered comprehensively.(5) Wood property characteristic had a clone relationship with growth characteristic. Density and height,DBH showed negatively significant correlation, while wood volume showed positively insignificant correlation respectively. Microfibil angle and growth characteristics showed insignificant correlation, Tracheid length and growth also showed insignificant correlation, it showed poor positive correlation with height and DBH and showed insignificant correlation with wood volume, but tracheid width and ratio of length to width showed negatively significant correlation with growth characteristics. It would become difficult to improve two characteristics at the same time.(6) The variation law of every characterstic was as follows: the differences of early wood microfibil angle, tracheid length, ratio of length to width and late wood ratio of length to width were significant among clones.There were significant differences in the height, DBH, wood volume,density among repetitions,while the influences of clone and repetition were insignificant in the early wood tracheid width, late wood tracheid length and width.The correlation of clone and repetition were insignificant in all testing characteristics.