中文摘要：

荒漠草本植物是荒漠生态系统物种多样性的主体，对其生物量分配及叶片化学计量特征随植物生长的变化规律的研究有助于深入了解荒漠草本植物生存策略和功能特征。该文选择古尔班通古特沙漠4种优势草本（2种短命植物，2种一年生长营养期植物）为研究对象，通过野外原位多时段取样，对比研究了四者生物量分配、叶片N—P化学计量学随植物生长的变化特征，以及二者之间的关系。结果表明，在生物量累积过程中，4种植物根冠比逐渐减小，地上与地下生物量间的相关生长关系也发生变化，其中琉苞菊（Hyalea pulchella）和角果藜（Ceratocarpus arenarius）的相关生长指数先增加后减小，并趋于稳定，而尖喙栊牛儿苗（Erodium oxyrrhynchum）和沙蓬（Agriophyllum squarrosum）的相关生长指数由小到大并趋于等速生长。琉苞菊叶片N、P含量呈逐渐增长趋势，而另外3种植物呈下降趋势，表明所研究的荒漠植物在生长过程中，叶片N．P化学计量发生改变，叶片化学计量特征与生物量指标的相关性较弱。

英文摘要：

Aims Plant biomass allocation and elemental homeostasis have recently become a focus in ecological studies. Herbaceous plants are a major component of species diversity in desert ecosystems. Study on biomass allocation and leaf stoichiometry with growth will be beneficial to further understanding the survival strategy and functional features of desert herbs.Methods Four dominant species, including two ephemeral plants （Erodium oxyrrhynchum and Hyalea pulchella） and two annals （Agriophyllum squarrosum and Ceratocarpus arenarius）, were selected for in situ and multiple-time investigations. Changes in the characteristics of biomass allocation and leaf N-P stoichiometry, as well as their relationships were analyzed.Important findings Root to shoot ratio decreased gradually during the accumulation of plant biomass in all the four species. The allometrie relationships between above-and belowground biomass, however, varied among the four species; the allometrie scaling exponents in H. pulchella and C. arenarius initially increased and then decreased, and tended to become stable toward the later period, whereas the allometric scaling exponents in E. oxyrrhynchum and A. squarrosum initially increased and then tended to be isometry in later period. The leafN and P contents tended to increase in H. pulchella, but declined in other three species with growth, indicating that the leaf N-P stoichiometry of the plants studied ehanged and showed weak correlations with biomass indices.