羊草群落不同优势植物光能和水分利用特征比较的研究

用CI-301PS光合作用测定仪测定了大针茅(Stipa grandis)、羊草(Leymus chinensis)、羽茅(Achnatherum sibiricum)和黄囊苔草(Carex korshinskyi)的净光合速率和蒸腾速率的日动态．分析结果表明四种植物光能利用效率的日动态都呈峰值明显的双峰型曲线,黄囊苔草光能利用效率的日动态明显不同于其它三种高大禾草;四种植物水分利用效率的日动态都呈单峰型曲线,但日变化韵律和峰值出现时间有明显差异．四种植物的光能利用效率日变化与水分利用效率日变化都有显著线性相关关系．黄囊苔草和大针茅的光能利用效率都与气孔阻力、温度有显著线性相关关系;黄囊苔草的水分利用效率与气孔阻力、大气温度和相对湿度有显著线性相关关系,羊草的水分利用效率与气孔阻力、叶面温度有显著线性相关关系．

A Comparative Study on Light-and Water-use Characteristics of Dominant Plants in Leymus chinensis Steppe Community

Photosynthesis instrument (CI-301PS) was to measure net photosynthesis rate and transprition rate of Stipa grandis,Leymus chinensis,Achnatherum sibiricum and Carex korshinskyi..It was found that curve of diurnal changes of light use efficiency of four plants tended to "double peaks", but the curve of Carex korshinskyi was differed from the others .The curve of diurnal changes of water use efficiency of the four plants tended to "single peaks", but the rhythm of diurnal changes and the time of peaks appeared were different among them. There were remarkable linear correlation between diurnal changes of light use efficiency and diurnal changes of water use efficiency in four plants. The diurnal changes of light use efficiency of Carex korshinskyi and Stipa grandis were respectively correlated to stomatal resistance and temperature.The linear correlation between diurnal changes of water use efficiency of Carex korshinskyi and stomatal resistance,air temperature and relative humidity was remarkable. There was remarkable linear correlation between diurnal changes of water use efficiency of Leymus chinensis and stomatal resistance,leaves temperature.