围栏封育对珠芽蓼繁殖策略的影响

Effect of fenced enclosure on the reproductive performance of Polygonum viviparum

【目的】研究围栏内和围栏外植物的繁殖行为差异能反应围栏封育对植物繁殖策略的影响,研究结果能评价围栏封育在草地生态系统恢复和草原管理中的应用.【方法】以海北高寒草甸生态系统定位站附近围栏内外草甸群落中的珠芽蓼为研究对象,通过野外取样和统计测量,探讨围栏对珠芽蓼有性繁殖模式(花)和无性繁殖模式(珠芽)的影响.【结果】围栏内珠芽蓼的植株高度和珠芽数量显著高于围栏外,而围栏内植株的花数量和花比例显著低于围栏外;珠芽蓼的植株高度与珠芽数量之间存在显著的正相关关系,但植株高度与花数量及花所占的比例之间均存在不显著的负相关关系;珠芽蓼的花数量和珠芽数量存在显著的负相关关系.【结论】围栏封育会增加珠芽蓼在生长和无性繁殖方面的营养投资,降低珠芽蓼对有性繁殖的投资,但围栏封育后引起植物资源分配的这些变化是否具有普遍意义仍需要在更多的植物中验证.

【Objective】Fenced enclosure is one of the important methods for restoration and management of grassland ecosystems,but it is still unclear on the effects of fenced enclosure on reproductive allocation of plant species.【Method】In this research,changes of the sexual and asexual reproductive allocation inside and outside the enclosure were examined near the Alpine Meadow Ecosystem Station in Haibei between two populations of Polygonum viviparum,which could reproduce sexually via seeds and asexually via bulbils.【Result】The results showed that plant height and bulbil number of P.viviparum inside enclosure was significantly more than those of plants outside enclosure,but flower number and flower proportion of plants inside enclosure was significantly less than those of plants outside enclosure.There was a significant positive relationship between plant height and bulbil number,but the negative relationships between plant height and flower number and flower proportion were not significant.A significant negative relationship between bulbil number and flower number was found in each of the two populations of P.viviparum.【Conclusion】The results suggest that fenced enclosure would increase resource allocation to vegetative growth and asexual reproduction of plant species and decrease resource allocation to sexual reproduction,but whether or not this pattern is general still needs to be discovered in other plant species.