关键词: 大针茅, 构件, 地理变异, 方差分析, 变异组分分析, 分形维数

Abstract: The quantitative characters of Stipa grandis clonal populations found in three habitats with different climatic conditions in the Xilingol plateau of Inner Mongolia, were studied by means of one way ANOVA, analysis of variance components and fractal geometry. (1) The three populations had different growth patterns in plant height of vegetative modules in the growing season; plant height of vegetative modules or reproductive modules varied significantly among S. grandis populations and most variation existed among populations. (2) There were significant fractal relationships between aboveground dry matter weight and height of vegetative modules of S. grandis populations in different growth periods of the plant; the fractal dimension value was consistent with the biomass accumulation of vegetative modules when the habitats were not intensively disturbed; while a very rapid increase happened under long-term severe drought conditions. (3) There were also significant fractal relationships between aboveground dry matter weight and plant height of vegetative modules of S. grandis populations in the growing season, furthermore, the values of fractal dimension varied significantly among different populations. All the divergences among different habitats were supposed to be attributed to long-term local adaptation and natural selection.

Key words: Stipa grandis P. Smirn, modules, geographic variation, analysis of variance, analysis of variance components, fractal dimension