A statistical analysis was conducted on the configurations of branch system of Haloxylon amnodendron in different growth stages (3 to 11-year-old) occurring in Minqin desert.1)No significant differences were found among different stages in the coefficients of branching patterns,overall bifurcation ratios,and the branch angles,and the overall bifurcation ratio was lower.2) In the early stages of the growth,the values of stepwise branching rate SBR1∶2 were higher than those in late stages,while the values of SBR2∶ 3 in early stages were lower than those in late stages.3) The branch angles decreased with the increase of the branch classes,young branches that were close to the top of a plant were in an angle about 30° to the stem,while the old branches that were close the ground were in an angle about 60° to the stem.4) Significant differences were found in branching lengths at all branch classes (p＜0.05).The stretch abilities of the branches tended to become weak along with the increase of branch classes.5) Along with the developmet of individual growth,differences in diameter ratio were significant (p＜0.05).As the increase of branch classes,diameter ratio tended to increase,indicating the increase of bearing capacity.The branch system configuration of H.ammodendron in different growth stages demonstrated its adaptability to the desert environment.%通过对民勤荒漠植物梭梭(Haloxylon ammodendron)不同生长发育阶段(3～11 a龄)枝系构型进行了统计分析.结果表明:1)梭梭不同生长阶段的分枝格局参数,总体分枝率和分枝角度差异不显著,且总体分枝率均较低.2)梭梭生长初期逐步分枝率(SBR)1∶2大于生长后期,而梭梭生长初期(SBR)2∶3小于生长后期.3)梭梭的分枝角度随级数的增加而呈现减小的趋势,梭梭在越靠近植株顶端,年幼的枝和干之间的分枝角度越接近于30°,而在越靠近植株基部的老枝和干之间的分枝角度多接近于60°.4)梭梭的各级分枝长度存在显著差异(p＜0.05),梭梭枝条的伸展能力从低级到高级呈现相对减弱的趋势.5)随着梭梭个体生长发育,其植株的枝径比差异显著(p＜0.05),随分枝级数的增加,其枝径比呈现出逐渐增大的趋势,说明其枝条间的承载力越大.梭梭在不同生长发育阶段,枝系构型表现出一定的可塑性,反映了对荒漠环境的适应.
展开▼
