Abstract:

Abstract: The well distributed and planted poplar clone 107 was selected as studying materials in this study. Surface longitudinal growth strain and inner residual longitudinal growth strain were determined. Both variation patterns of the surface strain and the inner strain were deduced. The result indicated that varied scope of the surface strain was-853.10～-213.43 με, and changing range of the surface strain among different periphery positions was relative narrower at tree Z1, Z3 and Z4, however, larger one was found at tree Z2, and Z5. When it came to variation along tree height, the surface strain increased from basement to upward as compression strain, namely tension stress, and reach the maximum at 10% of total height of tree, and then changed into decreasing. Result of double factor AVONA suggested that there were no significant effect was found both by different trees and different periphery positions on the surface strain, conversely, apparent effect of different heights on the surface strain was detected. Varied scope of the inner strain was -1 279.00～－960.20 με. Radial variation pattern was that the inner longitudinal compression strain (tensile stress) was decreasing from the bark to inside, and turned into tension strain (compressive stress) at the fifth or sixth growth ring at north part of center board and fourth or fifth growth ring at south part of the board. The maximum of tension strain of Z2 and Z5 tree located at the third growth ring of south part of the board, and Z3 tree at the same growth ring of north part of the board. General radial variation trend curve of the inner strain was similar to a parabola with a downward opening, and the maximum value located at pith. Quadratic regression equation of the inner growth strain to number of growth years was Y(innergrowth strain)＝815.02 X²(number of growth ring)-69.345 X-1 902.403, R²=0.775.

Key words: Key words: poplar clone 107, growth strain, distribution pattern