外来克隆植物关节酢浆草地下克隆储存对刈割的响应

Responses of underground clonal storage to mowing of the alien clonal weed species Oxalis articulata

外来克隆植物关节酢浆草被大量应用到中国园林绿化中,并出现逃逸和归化现象.关节酢浆草地下块茎的克隆储存可能对其潜在入侵性发挥了重要作用.本文基于盆栽试验并模拟园林除草措施进行人工刈割,比较植物各器官生物量、生物量分配,以及根、茎、叶主要功能性状等指标的差异,研究关节酢浆草的克隆储存策略对人工刈割的响应,从克隆储存角度分析植物的入侵机制.结果表明:刈割强度、刈割频度以及它们的交互作用显著影响了叶、根的部分生长指标,但地下茎生物量、总生物量在不同刈割条件下没有显著变化,且高频度刈割显著增加了植株对地下茎的生物量分配.关节酢浆草地下块茎的克隆储存功能,能够在一定程度上增强关节酢浆草对环境干扰的适应能力,从而促进其潜在的入侵性.

Oxalis articulata, an alien clonal plant species, is widely cultivated in China as an ornamental species, and has escaped and became naturalized. Belowground storage in tubers of O. articulata may play a key role for the potential invasion. In this study, we investigated the responses of its clonal resource storage strategy to mowing, aiming to uncover the mechanism underlying their invasion from a perspective of clonal storage. We examined the changes of biomass in different organs, biomass allocation, and several functional traits of roots, tubers and leaves in O. articulata by conducting a greenhouse experiment. The results showed that significant main and interactive effects of mowing intensity and mowing frequency on some functional traits of leaves and roots were found. In contrast, tuber biomass and total biomass did not vary under different mowing treatments. The frequent mowing significantly increased the biomass allocation to tubers. These findings demonstrated that clonal storage, to some extent, could enhance the resistance of O. articulata to environmen tal disturbance, which might promote its invasiveness.