展毛翠雀花期繁殖特征和生物量分配对放牧的响应

生物量分配影响植物生长和繁殖,是植物生活史研究的重要内容。为了了解植物生活史性状对放牧的响应,该研究以青藏高原高寒草甸毒杂草展毛翠雀为对象,分析了放牧干扰对展毛翠雀的花期繁殖分配和性分配的影响。结果表明:放牧显著降低了展毛翠雀的总生物量、个体大小和繁殖投入; 放牧未改变展毛翠雀的营养部分与繁殖部分的等速生长关系,但显著增加了繁殖部分的生物量分配和总花数; 展毛翠雀的个体大小与总花数呈显著的正相关关系,但与性分配呈显著的负相关关系; 展毛翠雀的总花数与单花大小、单花的花瓣比例均表现出负相关关系,表明总花数与单花大小之间、总花数与单花的花瓣比例之间均存在权衡。因此,在放牧条件下,展毛翠雀的繁殖分配和性分配均表现出显著的可塑性。

Responses of reproductive traits and biomass allocation in Delphinium kamaonense var. glabrescens at flowering stage to grazing

Biomass allocation influences many aspects of plant growth and reproduction, and is a major element in the research of plant life history. Focusing on Delphinium kamaonense var. glabrescens, a weed in the alpine meadow on the Qinghai-Tibet Plateau, we studied the influence of grazing on the reproductive and sexual allocation at flowering stage. The results showed that grazing significantly affected the total above-ground biomass, vegetative biomass and reproductive biomass of the plant. There was an isometric scaling relationship between the vegetative and the reproductive biomass, and grazing significantly increased reproductive allocation. There was a significant positive correlation between the individual size and the total number of flowers, but a significant negative correlation between vegetative biomass and sexual allocation. Grazing had no significant effects on sexual allocation. There were significant negative correlations between the total number of flowers and single flower size, and the total number of flowers and the proportion of flower petals in a single flower. These results indicated that there were trade-offs between the total number of flowers and single flower size, and between the total number of flowers and the proportion of flower petals in a single flower. Both reproductive and sexual allocations showed significant plasticity in response to grazing