The characteristics of stoloniferous herb Fragaria vesca L. ramet population and their variation along an altitudinal gradient in the eastern edge of the Qing-Zang Plateau in China
青藏高原东缘匍匐茎草本野草莓的分株种群特征及其沿海拔梯度的变化

Stoloniferous herb Fragaria vesca was sampled in the unshading (open fields) and the shading conditions (forest undergrowth) at the five different altitudes (2426m, 2750m, 3200m, 3484m and 3944m) in the eastern edge of Qing-Zang Platea u in China in order to investigate the characteristics of its ramet population a nd their variation along the altitudinal gradient. The resul ts show that its ramet population density decreased with increase of altitude, b oth under the unshading and the shading conditions. Under unshading conditions, its ramet population density was significantly higher than that under shading co nditions. The interaction of elevation by light was significant with respect to ramet population density. Under unshading conditions, its ratio of root to shoo t varied quadratically with increase of elevation. Under shading conditions, its ratio of root to shoot was smallest at 2426m above sea level than those at the other four altitudes. There was not significant effect of the light condition on the ratio of root to shoot. The distribution pattern of Fragaria vesca rame t po pulation at 3484m above sea level and 3944m above sea level was investigated by using spatial auto-correlation analysis (Moran`I). The results show that the ra met population of Fragaria vesca had non-random distribution pattern at mul tipl e scales and the most frequently observed pattern was contagious at the scale of d=1(0.2m). The maximum size of ramet cluster was bigger at 3944m above sea level than that at 3484m above sea level. Finally, the results were discussed i n the context of adaptation of clonal plants to environments.