中文摘要：

以往种群空间格局的研究大多基于植株点位或株数（0维），极少针对植冠的投影盖度（2维）和生物量（3维，由植冠体积体现）．目前对三者所体现的种群空间格局特征尚不清楚．本研究以古尔班通古特沙漠广布的小半灌木白茎绢蒿和准噶尔沙蒿种群为对象，测定每株的点位、投影盖度及地上生物量，通过GIS技术对坐标系进行6次尺度划分，利用聚集度分析、变异系数及其与尺度的幂函数关系，分析了3个参数的种群分布格局特征．结果表明：在各尺度下，两种群的株数（白茎绢蒿0．5m尺度除外）和生物量均为集群分布，聚集强度随尺度增加而增大；而投影盖度多为均匀分布（准噶尔沙蒿5m和8m尺度除外）．随尺度增大，两种群各参数的变异系数均逐渐下降；株数的幂指数的绝对值（k值）高于投影盖度和生物量，且后两者无显著差异．白茎绢蒿各参数的k值均高于准噶尔沙蒿，可能与群落种间关系及个体大小有关．总之，株数和生物量的空间格局类型相似，而投影盖度和生物量具有近乎相同的格局复杂性和尺度变化特征．

英文摘要：

The researches on the plant population spatial pattern were mostly based on 0-D plant point （0-D IND） or 0-D plant count, and only a few was based on the 2-D projective cover （2-D PC） and 3-D aboveground biomass （3-D AGB reflected by canopy volume）. Until now, the plant population spatial distribution patterns incarnated by these parameters were still unclear. Taking the widely distributed small semi-shrubs Seriphidium terrae-albae and Artemisia songarica in Gurban- tunggut Desert of Northwest China as test objects, this paper studied the IND, PC, and AGB of each individual at two sampling plots. Through six-scale division of plot coordinate system with GIS, and by using aggregation analysis, coefficient of variation （CV）, and a scaling exponent be- tween the CV and six scales, the characteristics of the population spatial distribution patterns with the above mentioned parameters were comparatively analyzed. At all scales, the IND（ except for the S. terrae-albae population at 0.5 m scale） and the AGB of the two shrubs all presented a clumped distribution, and the aggregation intensity increased with increasing scale. However, the PC had a uniform distribution （except for the A. songarica population at 5 and 8 m scales）. With increasing scale, the CV values of the two shrubs decreased. The absolute value of scaling exponent （ k value） of the IND was higher than those of the PC and AGB, and there was no significant differ- ence in the k values between the PC and AGB, indicating that the scale variation scone of the stn~c-tural complexity of the IND was larger than that of the PC and AGB. The k value of each parameter for S. terrae-albae was higher than that for A. songarica, which could be related to the populations＇ interspecific relationship and plant size. In sum, the IND and AGB had similar spatial patterns, while the PC and AGB had almost same spatial pattern complexity and scale change characteristics.