准噶尔盆地梭梭、白梭梭植物构型特征

Plant architecture characteristics of Haloxylon ammodendron and Haloxylon persicum in Zhungar Basin

荒漠植物构型是植物与环境相互作用、相互适应的最终产物,其与功能的相互作用与互馈关系决定了荒漠植被的发展与演替。选择准噶尔盆地天然梭梭(Haloxylon ammodendron)、天然白梭梭(Haloxylon persicum)和人工种植梭梭(Haloxylonammodendron)为研究对象,系统研究了天然梭梭、天然白梭梭和人工梭梭分枝率、分枝角度、分枝长度和枝径比等构型特征,对比研究了天然生境梭梭和人工种植梭梭构型差异,探讨了荒漠植物结构-功能特征及其对环境的响应与适应机理。结果表明:天然梭梭、天然白梭梭和人工梭梭的总体分枝率及逐布分枝率(SRB1∶2、SRB2∶3)均差异显著(P<0.05),且总体分枝率均较低,分别为0.35±0.23、0.50±0.42和0.15±0.05。天然梭梭、天然白梭梭和人工梭梭的分枝角度差异均不显著(P<0.05),从第1级到第4级均有减小趋势,角度均小于90°。天然梭梭、天然白梭梭和人工梭梭分枝长度从第1级到第4级排序为天然白梭梭>天然梭梭>人工梭梭,且天然梭梭、天然白梭梭和人工梭梭枝条伸展能力从第1级到第4级呈现相对减弱的趋势。天然梭梭、天然白梭梭和人工梭梭枝径比平均值分别为0.66、0.68和0.69。总体上,天然生境中梭梭、白梭梭构型为不同宽窄的"V"型,而人工梭梭呈现椭球形构型。

Plant architecture is defined as spatial arrangement of plant body such as the branching pattern,the shape and position of leaves and flower organs.The architecture of a plant depends on the nature and relative arrangement of each of its part;it is,at any given time,the expression of equilibrium between endogenous growth processes and exogenous constraints exerted by the environment.Desert plants architecture is a final product of plant-environment interaction,mutual adaption,thus the interaction and feedback among them would determine the development and succession of desert plant.Natural Haloxylon ammodendron and natural Haloxylon persicum are native dominant species in Zhungar Basin,which also are regarded as the important wind-preventing and sand-fixing plants.Because natural H.ammodendron and natural H.persicum are the characteristic of tolerant to dry,infertile soil,and wind-erosion,both as the ideal desertification combating species have played important roles in the maintenance of stability of fragile desert ecosystem.Therefore,natural H.ammodendron,natural H.persicum and artificial planting H.ammodendron were selected as the objects of study in Zhungar Basin.In order to understand the function and structure characteristics of desert plant and the response and adaptation mechanisms of plant-environment,the plant architecture characteristics（the bifurcation ratio,the branch angle,the branch length,the ratio of branch diameter,and so on） of natural H.ammodendron,natural H.persicum and artificial planting H.ammodendron were studied.The results showed that the over bifurcation ratio and the stepwise bifurcation ratio（SRB1∶2、SRB2∶3） were significant differences in natural H.ammodendron,natural H.persicum and artificial planting H.ammodendron（P0.05）,and the over bifurcation ratio of natural H.ammodendron,natural H.persicum and artificial planting H.ammodendron were 0.35±0.23,0.50±0.42 and 0.15±0.05,respectively.However,the branch angle of natural H.ammodendron,natural H.persicum and artificial planting H.ammodendron gradually decreased from first class to fourth class,the angles were less than 90°,and no remarkable difference among them were found（P0.05）.The order of the branch length of natural H.ammodendron,natural H.persicum and artificial planting H.ammodendron were natural H.persicum natural H.ammodendron artificial planting H.ammodendron from first class to fourth class.The average ratio of branch diameter of natural H.ammodendron,natural H.persicum and artificial planting H.ammodendron were 0.66,0.68 and 0.69,respectively,and ratio of branch diameter of artificial planting H.ammodendron was bigger than natural habitat H.ammodendron and H.persicum.As a whole,the architecture of natural habitat H.ammodendron and H.persicum performed a different width ＂V＂ type,but artificial planting H.ammodendron was spheroid-ellipse.Therefore the understanding of the desert plant architecture,spatial distribution pattern and micromorphology would contribute to further recognize the ecological adaption mechanism for the desert plants,which will favor desert plant community ecology theory and provide theoretic reference for choosing optimum plant species in desertification combating.