青藏高原东缘禾叶风毛菊的繁殖分配与海拔的相关性

通过采样调查法和烘干称重法，对分布在青藏高原东缘不同海拔高度的禾叶风毛菊的繁殖分配的特征进行研究。结果表明：（1）随着海拔的升高，禾叶风毛菊的个体大小、营养器官生物量、繁殖器官生物量、个体管状小花数目、雄蕊质量均与海拔呈负相关关系（P<0.01）；繁殖分配、管状小花生物量、雌蕊质量均与海拔呈正相关关系（P<0.01）；（2）繁殖分配是依赖个体大小的，个体越大，繁殖分配越小（P<0.01）；（3）禾叶风毛菊个体管状小花的数目及重量（P<0.05）、雌雄蕊重量（P<0.05）之间存在权衡关系。由此推论：（1）海拔作为外界因子对禾叶风毛菊花期各生物量及繁殖分配有显著的影响，但海拔并不是影响禾叶风毛菊繁殖分配唯一生态因子，植株个体大小也与其繁殖分配策略密切相关；（2）禾叶风毛菊的垂直分布的特征很有可能就是海拔通过影响植株个体大小变化来完成的。

Correlation between Reproductive Allocation and Elevation of Saussurea graminea in Eastern Margin of the Tibetan Plateau

Westudied the effect of elevation on the reproductive allocation of Saussurea graminea in Qinghai-Tibetan Plateau, China.We used the field investigation method and dry mass method to evaluate morphological characteristics of S.graminea at different elevations. With the increase of altitude,the reproductive allocation,each tubula r loret mass and mass of pistil were positively correlated with elevation, but individual size, reproductive organ biomass, vegetative organ biomass, tubular loret number and mass of stamenwere negatively correlated with elevation; the reproductive allocation is negatively correlated with individual size. There are trade-offs of reproductive allocation in tubular loret number and mass as well as mass of pistil and mass of stamen. Theelevation had a significant impact on the biomass and reproductive allocation of S.graminea.The altitude could not fully explain the change of reproductive allocation strategy of this alpine perennial, and the reproductive allocation is limited by individual size of S.graminea. The characteristics of vertical distribution of S.graminea is likely to be completed by the individual size of the plant.