Abstract: Reproduction has a very close relationship with species survival and development, and is the core in the study of plant life history. The environmental factors under the restriction by altitude have significant effects on the reproductive allocation of plants. In July 2010, a quadrat
investigation was conducted to study the characteristics of the reproductive allocation of S. chamaejasme population at four altitudes with a gradient from 2700 m to 3000 m. With the increasing altitude, the aboveground biomass of S. chamaejasme presented a decreasing trend, but the total flower biomass and the plant height increased after an initial decrease, and the reproductive allocation had an increasing trend. Along the altitude gradient, the reproductive allocation had a significant negative correlation with the total aboveground biomass (except at altitude 2800 m), but less correlation with the plant height (except at altitude 3000 m). The reproductive allocation of S. chamaejasme population was limited by plant body size, and the limitation by total aboveground biomass was far larger than the limitation by plant height, indicating that with the increasing altitude, S. chamaejasme population could ensure its reproductive success via reducing the plant body size to decrease the resource consumption and increasing the allocation of the obtained limited resources to flower biomass.

Key words: Chinese alligator, Water environment, Heavy metals content, pH