The Study Of Growth Traits And Wood Fiber Characteristics Variation Of Ten Years Old Hybrid Eucalyptus Clones Forests

The aim of this thesis was to comprehensively evaluate the growth performance of 13 Hybrid eucalyptus clones forests of 10 years old.Through the investigation of the relevant growth traits of forest trees and detection of the fiber characteristics,mathematical and statistical analysis was carried out to screen the main influencing factors,and the growth performance of cloned forests was comprehensively evaluated.Correlation and variation of growth traits and fiber morphology of different hybrid carp clones,the main conclusions are as follows:(1)The experimental forests showed good overall performance with a preservation rate of 63.47%.A stand average diameter at breast height,tree height,volume,under branch height and trunk form index were 17.56 cm,22.89 m,0.3258m3,11.55 m and 3.36.(2)The DBH,tree height and volume all reached extremely significant levels.The best and worst clones are GL9 and LH1 evaluated in combination with the preservation rate.The optimal value was U233 and the worst was GLGul2.(3)The average value of oven-dry density was 0.5332g/cm3,the largest cone was M1 and the smallest was DH33-27.The overall trend of oven-dry density of each cone is:sapwood>medium>heartwood.(4)The fiber length ranged from 878.24μm of SH1 to 1068.75μm of GL9,with a mean value and coefficient of variation was 973.59μm and 4.95%.The wood fiber width ranges from 14.26μm of SH1 to 17.94μm of DH33-27,with a mean value and coefficient of variation 16.26μm and 6.91%.(5)The fiber double wall thickness ranges from 6.47μm to 7.58μm,the average value was 6.98μm,the coefficient of variation was 5.22%,and the largest clone is DH32-13 and the smallest is SH1.(6)The ratio of fiber length and width ranged from 57.96μm of DH32-11 to 68.37μm of U233 with a mean value of 62.67μm.The ratio of double wall thickness and diameter ranged from 0.68 of GU12 to 1.02 of DH32-13,with a mean value of 0.86.The average ratio of fiber diameter and width ranged from 0.52 of DH32-13 to 0.61 of GU5,with a mean value of 0.56.(7)The fiber length,fiber width,double wall thickness,aspect ratio and wall cavity ratio of the tree different parts of the clones are as follows:sapwood>medium>heartwood in radial variation,and the average ratio of fiber diameter to width is heartwood>medium>sapwood.(8)There’re positive relationships between diameter and tree height,trunk form index,crown and fiber length.Similar relationships are also existed between tree height and under branch height and trunk form index.Basic density was negatively correlated with fiber width,and fiber length was positively correlated with fiber width.Same relationships were also existed between fiber length and cavity diameter and cavity ratio.