Study On The Wood Anatomy Of Chinese Fir In Different Growth Environment

Wood anatomy of 12-13 year old Chinese fir plantation in different growth environments (south hillside, mountain valley, ridge, mountain top) was studied by measuring annual ring width, late wood percentage, tracheid length, tracheid width, thickness of cell wall, ratio of length to width, ratio of cell wall to cavity, microfibrillar angle, proportion of wood tissues, air-dried density. Research results showed that, firstly, there were significant differences in annual ring width and late wood percentage among the whole trees in different growth environments in the order mountain valley (7.1mm ) >south hillside (6.4mm ) >ridge (5.7mm ) >mountain top (5.6mm ) >compression trees(4.2mm) and the order mountain valley(51.9%)>compression trees(42.4%)>ridge(40.2%)>south hillside(36.0%)>mountain valley(35.7%) respectively. There were significant differences in annual ring width in the order mountain valley (5.6mm ) >south hillside (5.3mm ) >ridge (5.0mm )>mountain top (4.8mm) but no significant ones in late wood percentage among the 0.5Abstractmeter of height in different growth environments. Secondly, the differences of tracheid length, tracheid width, ratio of length to width of both early wood and late wood were insignificant among the whole trees and the trees of 0.5 meter height as well in different growth environments. However, there were significant differences in thickness of cell wall of both early wood and late wood in the order ridge ( 7.36 m) >compression trees (6.28 m) >south hillside (6.2 m) >mountaintop (5.83 m) >mountain valley (5.38 m) and the order ridge (12.13 m ) >compression(11.71 m)>mountain top(10.32 m)>south hillside(9.21 m)>mountain valley(8.75 m) respectively among the whole trees in different growth environments and the differences were also significant in ratio of cell wall to cavity of late wood in the order compression trees(0.526)>ridge(0.511 )>mountain top(0.414)>south hillside(0.388) >mountain valley(0.365) among the whole trees in different growth environments. The differences were insignificant in ratio of cell wall to cavity of early wood among the whole trees and of both early wood and late wood among the trees of 0.5meter height in different growth environments. Thirdly, the radial variation patterns of microfibrillar angle were gradually decreasing from pith to bark and the differences were insignificant of microfibrillar angle of both early wood and late wood among the tree of 0.5meter height in different growth environment. Fourthly, the differences of proportion of longitudinalparenchyma, proportion of wood ray and proportion of tracheid were insignificant among the trees of 0.5meter height in different growth environments. Fifthly, there were significantly positive correlations between air-dried density and late percentage, tracheid thickness of cell wall and proportion of tracheid and negative correlation between air-dried density and microfibrillar angle. The differences of air-dried density were significant in the order ridge (0.451 g/cm3 ) >mountam top(0.411 g/cm3)>south hillside(0.396 g/cm3)>mountain valley(0.381 g/cm3) among the trees of 0.5meter height in different growth environments. Sixthly, the boundary between juvenile wood and mature was the sixth year.Chinese fir plantations for providing with excellent wood can be developed by selecting suitable growth environments according to wood properties and characteristics wood because properties and characteristics have a quite close relationship with growth environments. The significantly remarkable properties and features among the Chinese fir trees in different environment can provide theoretic basis for developing Chinese fir short period plantations owning good properties and characteristics for providing wood to accommodate different uses.