3种棒果芥属植物生物量分配及异速生长分析

类短命植物是准噶尔荒漠早春草本植物类群的重要而独特的组成部分,研究其生物量分配和异速生长关系,有助于深入了解类短命植物的生存策略与生态功能。以棒果芥（Sterigmostemum tomentosum）、福海棒果芥（S. fuhaiense）和黄花棒果芥（S. sulfureum）为研究对象,采用挖掘法获取野外成株全株生物量,对三者的器官生物量、分配比例及异速生长关系进行了对比分析。结果表明,3种植物器官生物量及其分配比例均差异明显。福海棒果芥生物量最大,但根冠比（R/S）和叶冠比（L/S）最小;棒果芥生物量最小,但L/S最大;黄花棒果芥则具有最大的R/S。棒果芥和黄花棒果芥的根冠比（R/S）均随个体的增大而显著下降,表明二者地上（AGB）与地下生物量（BGB）分配受到个体大小的强烈影响。福海棒果芥AGB-BGB间为等速生长关系（幂指数α=1）,而另外2种均为异速生长关系;棒果芥、福海棒果芥的叶生物量（LB）与AGB间为等速生长关系,而黄花棒果芥符合异速生长关系（α<1）;3个物种的LB-BGB间具有共同的异速生长指数（0.816）,表现出强烈的功能趋同性。总之,3个物种间的生物量分配及异速生长关系没有一致规律,但体现了类短命植物生物量分配的特点。

Analysis of biomass allocation and allometric growth of three Sterigmostemum species in Junggar Basin

The ephemeroid plants are an important and unique component of the early spring herbaceous plants community in Junggar Basin of China. The study on relationship between biomass allocation and allometric growth in ephemeroid plants will contribute to deepen understanding about their survival strategy and ecological function. Sterigmostemum tomentosum, S. fuhaiense, and S. sulfureum were used, the total plant biomass of mature individuals were obtained by using excavation in the field, and organ biomass, allocation ratios and the allometric relationships among the three species were compared. The results showed significant difference in organ biomass and biomass allocation ratios among the three species. S. fuhaiense had the largest biomass, but its ratio of root to shoot (R/S) and the ratio of leaf to shoot (L/S) were the lowest. S. tomentosum had the smallest biomass, but L/S was the largest. S. sulfureum showed the largest R/S. The R/S of S. tomentosum and S. sulfureum declined noticeably with increasing of plant biomass, indicating that allocation of aboveground biomass (AGB) and belowground biomass (BGB) were strongly influenced by plant size (biomass). The biomass pair AGB-BGB of S. fuhaiense showed an isometric effect (i.e. their allometric scaling exponents were 1.0), while the other two species showed allometric effect (the exponent< 1.0). The biomass pair AGB-LB of S. tomentosum and S. fuhaiense showed an isometric effect; whereas S. sulfureum fited the allometric relationship. The biomass pair LB-BGB of all the three species exhibited a common allometric scaling exponent (0.816), showing a strong functional convergence. In conclusion, there was no consistency between allocation pattern and allometric relationship in three Sterigmostemum species, but it represented the biomass allocation characteristics of ephemeroid plants.