【摘要】 <正> 前言西伯利亚杏(Prunus sibirica L.)主要分布在森林草原带,常成为山地灌丛和灌木草原的优势种和景观植物;在典型草原带的沙地上也有分布,并常常集中地分布在固定沙丘阳坡上,形成独特的沙地灌丛。西伯利亚杏属于旱中生灌木或小乔木,耐寒性强,又能抗旱,五月份开花,粉红色花更多还原

【Abstract】 Water relation of Prunus sibirica shrub which distribute over the sun-slope of sand dune in the semi-arid steppe zone was analysed. （1） With photosynthetic photon flux density （PPFD） and air temperature （T） changing, the daily changes of the leaf diffusive resistance（R_L） and the leaf transpiration rate（T_R） appeared obviously. From 6: 00——18: 00 hour of the day, the changes of R_L ranged from 11.4 s·cm^-1 to 1.5 s·cm^-1; the changes of T_R ranged from 0.3ug·cm^-2·s^-1 to 5.0 ug·cm^-2·s^-1. The response of the lighted leaf to PPFD and T was more sensitive than the shaded leaf. The daily courses of T_R had 2-peak and 1-peak for the lighted leaf and the shaded leaf respectively. （2） The daily course of water flow rate through the Prunus sibirica shrub showed a symmetrical parabola. At noon （about 12: 00 hour）, the water flow rate appeared maximum, i.e. 3kg·h^-1. At about 5: 00 and 19: 00 hour, the water flow rate reduced to zero. （3） It was quite evident that the grandient of water potential in the soil——plant——atmosphere continuum of the shrub: soil——plant——atmosphere 0.05～0.8 1.2～2.3 500Mpa This grandient is the driving force for water transport from the soil, through the plant, to the atmosphere. （4） Using Ohm’s Law analogue, the water flow resistance （WFR） of the shrub was obtained, i.e. WFR=0.34 Mpa·h·kg^-1. This considerable value must be useful to maitain water balance in the shrub.更多还原