关键词: 油蒿, 杨柴, -3/2指数法则, 异速生长

Abstract: Through the study of the change in individual's size and allometric pattern of Artemisia ordosica and Hedysarum laeve populations distributing on the Mu Us Sandland,this paper has gained the following conclusions primarily:(1) The Artemisia ordosica individual's average size,average Height/Diameter ratio and static allometric coefficient don't change with the increase of density,and the curve of the static allometry is fit with the simple allometry type,this is because that the settlement and the growth pattern of Artemisia ordosica individual are mainly influenced by the water condition of the micro-habitat.(2) The average size of Hedysarum laeve individual decreases with density,and its self-thinning power is less than 3/2,this is probably because the canopy hasn't reach the 100% cover in higher density,and we can judge the 100% cover of the canopy by seeing if the total area of individual's canopy projection reach the ceiling value.(3) Hedysarum laeve individual's average size,average Height/Diameter ratio,and static allometric coefficient don't change with the increase of density,and the curve of the static allometry is fit with the simple allometry type too,that means the Hedysarum laeve's character of allometry don't change with the increase of light competition's intensity,this is probably because it can find a more suitable habitat by its rhizome's reproduction to produce a new branch,so it can avoid the light competition.

Key words: Artemisia or dosica, Hedysarum laeve, -3/2 power rule, allometry