水分胁迫对栓皮栎幼苗生理特性及生长的影响

通过盆栽实验，研究了在不同的水分条件下栓皮栎幼苗生理特性的变化和苗木生长量的变化。研究表明，在水分胁迫初期，随土壤含水量的降低，栓皮栎叶片的净光合速率、蒸腾速率下降，而水分利用效率提高。在水分胁迫末期，由于长期的干旱胁迫，水分条件最差的一组苗木已干枯死亡，土壤含水量从38．123％下降到20．323％时，净光合速率和蒸腾速率均下降，水分利用效率也下降。随着土壤含水量的降低，苗高、地径和生物量均有下降的趋势，其中生物量下降的幅度最大。

The effect of water stress on the photosynthetic characteristics and growth yield of oriental oak seedlings

The effect of water stress on the photosynthetic characteristics and growth of oriental oak seedlings was studied through potted seedlings. The experiment showed that in early water stress stage, the net photosynthetic rate (Pn) ,transpiration rate (Tr) of oriental oak seedlings decreased when the soil water content reduced, however, the water use efficiency (WUE) increased in the same process. Under light water stress, stomatal factors limited the Pn. However under serious water stress, the non-stomatal factors limited the Pn. In late water stress stage, because of long drought the group seedlings of the worst water condition died. The Pn ,Tr ,WUE, the height, the diameter at foot and biomass of oriental oak seedlings decreased when the soil water content reduced. The Pn decreased because of non-stomatal factors.