| In this paper, wood from Larix gmelini(Rupr) plantation was selected as studying materials. Axial surface growth strain and internal axial residual strain were tested in different terrain conditions and then researching on their anatomy, physical and mechanical properties of wood, etc., Variation patterns of growth strain of individual vertical and inclined tree was illustrated, and impacts of forest practice on growth strain of living standing tree were also revealed. Relationship between growth strain and wood properties was further expounded. All information from the paper aimed to reduce negative effect of growth stress of Larix gmelini(Rupr) and improve utilized rate and economic benefits of Larix gmelini(Rupr) plantation.Researching result as follows:1. At different terrain conditions, Larix gmelini(Rupr) tree growth at sunny slope and plain had lager difference of GSI (growth stress indicator) between north parts of trunk and south parts one than tree growth at shade slope. Variation range of GSI at different sites was 0.055μm-0.091μm at plain, 0.029μm-0.089μm at sunny slope, 0.007μm-0.030μm at shade slope.2. At different trunk shape, difference of GSI among four wise positions of vertical Larix gmelini(Rupr) standing tree was lower than inclined tree, and high inclined angle associated with higher GSI of leaned tree.3. General radial trend of inner residual longitudinal growth strain was similar to parabola with downward opening, and the maximum value located at pith for vertical tree and the minimum located at periphery of trunk. The general trend of vertical tree had high symmetry. Inclined tree had larger fluctuations in maximum and minimum value, the general radial trend was more like a "Z"-type distribution.4. The average tracheid length was 2125.43μm, the average tracheid width was 35.06μm, the average ratio of length to width of wood tracheid was 60.67, the average ratio of cell wall to lumen of wood tracheid was 0.33 and the average microfibrillar angle of wood tracheid was 27.37°. The fiber of Larix gmelini(Rupr) belongs to the long fiber, which is suitable or the pulp and paper fiber raw materials. The average tracheid length ranges from 2259.25μm to 2032.25μm, the average tracheid width from 36.08μm to 34.01μm; the average ratio of length to width from 64.81 to 56.39; the average ratio of cell wall to lumen from 0.3916 to 0.2917 and the average microfibrillar angle from 27.03°to 27.97°. The analysis of variance showed that the difference of tracheid morphological characteristics and microfibrillar angle among different trees was not significant. The radical variation pattern of tracheid length belongs the type of Panshin II; The tracheid width and the ratio of tracheid length to width increase gradually from pith to bark; The ratio of the cell wall to lumen increase from pith outward with fluctuation and the microfibrillar angle decrease gradually.5. The average basic density of Larix gmelini(Rupr) was 0.5556 g/cm3 , The average basic density of Larix gmelini(Rupr) ranges from 0.4242 g/cm3 to 0.6454g/cm3. Radial variation pattern of the basic density of Larix gmelini(Rupr) was accorded with the first category of Panshin general conformity which the basic density of wood was divided into three categories along the radial variation. Specific density was basically the smallest parts from the pith, and then a gradual increased to bark. One-way variance analysis showed that the density of Larix gmelini(Rupr) basic changes in the radial difference at 0.05 significant level.The average rate of volume shrinkage of oven-dried in Larix gmelini(Rupr) was 6.34%, the average rate of radial shrinkage of oven-dried in Larix gmelini(Rupr) was 1.98%, the average rate of tangential shrinkage of oven-dried in Larix gmelini(Rupr) was 4.23%. Variance of volume shrinkage of oven-dried in Larix gmelini(Rupr) was more significant among trees, and its value ranged from 4.48% to 7.59%. Variance of radical shrinkage of oven-dried in Larix gmelini(Rupr) was not obviously among trees, and its value ranged from 1.27% to 2.69%. Variance of tangential shrinkage of oven-dried in Larix gmelini(Rupr) was more obviously among trees, and its ranged from 2.73% to 5.00%. Difference of value of (TS) /(RS) among trees was obvious, and its value ranged from 2.15% to 3.58%. General regulation of shrinkage properties of could been drawn as follows: the volume shrinkage rate> the tangential shrinkage rate (TS)> radial shrinkage rate (RS), and tangential shrinkage rate (TS) was approximate 2 times to radial shrinkage (RS).The radical shrinkage and the tangential shrinkage increase gradually from pith to bark; The volume shrinkage increase from pith outward with fluctuation.6. The modulus of elasticity (MOE) of Larix gmelini(Rupr) between the trees was significant at 0.05 levels, and the overall average of 13.57 GPa, its value ranged from 9.33 GPa to 17.43 GPa. Bending strength of Larix gmelini(Rupr) (MOR) were significant differences among 3 trees, and the overall average of 102.94 MPa, ts value ranged from 85.98 MPa to 125.38 Mpa.7. Correlated analysis shown that inner residual growth strain negative correlated with tracheid length, tracheid width, and the ratio of tracheid length to width, and correlated coefficient was 0.8344, 0.7616, 0.6158 respectively. It illustrated that inner radial residual growth strain at pith show positive value (compressive strain), and it correlated to lower tracheid length, tracheid width, and the ratio of tracheid length to width. However, correlation between inner residual strain and Runkel ratio was unapparent, and coefficient was only 0.0003. Internal longitudinal residual strain increased with microfibrillar angle, and positive coefficient up to 0.6110.8. The internal longitudinal residual strain and the physical properties of wood had emerged negative correlation between each other, however no coefficient was significant. The correlationship between specific density and volume shrinkage rate, the rate of radial shrinkage, the rate of tangential shrinkage were weakly positive correlated, but significant correlation between the volume shrinkage rate and the lines shrinkage rate was found, correlation coefficients were 0.559, -0.489 respectively. Correlation coefficient between radial and tangential shrinkage rate was 0.621.9. Internal longitudinal residual strain and MOE,MOR were positive correlated with each other, and correlated coefficient of internal longitudinal residual strain and bending strength was significant at 0.01 levels. |
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