两种养分水平条件下结缕草分株生根比例变化对克隆生长的影响

以匍匐茎型克隆植物结缕草为研究对象，探讨其在不同土壤养分水平条件下，克隆分株生根比例变化对克隆生长的影响。实验设置高、低两种养分水平，以及0%，25%，50%，75%和100%五种克隆分株生根比例。结果表明：在不同养分水平条件下，结缕草分株生根比例变化对克隆植株整体生长影响程度不同。在养分水平较高时，分株生根比例变化对克隆植株总生物量影响显著，而在养分水平较低时，影响则不显著；无论在何种养分水平条件下，分株生根比例变化对克隆植株根生物量都有显著影响。克隆植株上75%分株生根时，具有最大的根生物量。分株生根比例变化影响了克隆植株的生长策略，并显著改变克隆植株的生物量分配格局。分株生根比例较低（0%和25%）的克隆植株根冠比较小，且匍匐茎生物量显著增加。整体来看，结缕草克隆植株的生长状况在高养分水平条件下明显好于在低养分水平条件下。

The Impacts of Rooting Proportions of Ramets of Zoysia japonica on Its Clonal Growth Under Two Nutrition Levels

Taking the stoloniferous clonal plant Zoysia japonica as research object, the impacts of rooting proportions of ramets on its clonal growth under two nutrition levels were studied. Five types of rooting proportion of ramets within the clones were designed in the experiment. The results showed that the differences in rooting proportions of ramets within the clones affected the clonal growth of Zoysia japonica to different degrees. In the habitats with high nutrient levels, the biomass of Z. japonica clones was significantly affected by changing the rooting proportions of ramets within the clones, whereas in habitats with low nutrient levels, the biomass of Z. japonica clones was not significantly affected. The changes of rooting proportions of ramets within the clones significantly affected the biomass of roots of the clones, no matter under what nutrient levels of habitats. The clones with 75% rooting proportions of ramets showed the maximum biomass of root. The changes of rooting proportion of ramets within the clones affected the growth strategy of Z. japonica and the allocation of biomass significantly. The clones with lower rooting proportions of ramets (0% and 25%) showed smaller R/S ratio, and the stolon biomass increased significantly. Overall, Z. japonica clones in high nutrition habitats grew better than those in low nutrition habitats.