土壤水分对华荠苧光合生理生态特性影响的研究

用闭路气流法对土壤相对含水量分别为100%、60%、40%和20%的环境下华荠苧的光合生理生态特性进行研究。结果表明,华荠苧日平均净光合速率(PNmean)、气孔导度(Gs)和水分利用效率(WUE)在60%水分处理下最高;叶绿素a含量和叶绿素a/b的值在100%和60%处理下较大,该水分条件可降低强光对植物的伤害。野外调查表明中生偏湿生境中华荠苧生长良好,但对这种生境的占据能力差,说明华荠苧的最适水分生态位为中生偏湿,野外华荠苧实际水分生态位与最适水分生态位不符,这可能是限制该物种野外种群扩大的主要原因。

Influence of soil moisture on photosynthetic physioecological properties of Mosta chinensis

A comparing analysis on photosynthetic physioecological properties of Mosla chinensis under four moisture treatments with relative soil water contents of 100%,60%,40% and 20%,respectively,has proved that the diurnal mean values of net photosynthetic rate(P_(Nmean)),stomatic conductance(Gs) and water use efficiency(WUE) of plants are the highest under 60% soil moisture,the content of chlorophyll and the ratio of chlorophyll a to b are higher both under 100% and 60% treatments.Plants living in these moisture conditions have a stronger capacity to reduce the hurts caused by effulgence.The field study shows that the plants living in mesophytic to slightly humid environments grow well,but their colonizing ability in the environments is weak.These results indicate that the most suitable moisture niche for Mosla chinensis is mesophytic and slightly humid,and the fact that plants can not occupy the most suitable water habitat in fields may be one of the major reasons restricting the population to extent quickly.