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为探讨沙棘对半干旱黄土丘陵区水分条件的适应性 ,1998年对沙棘的水分生理生态及抗旱性进行了分析研究。试验结果表明 :(1)沙棘适应半干旱黄土丘陵区生境形成了耐旱、御旱的双重抗旱方式。在旱季 ,沙棘体内束缚水含量随干旱加剧而上升 ,束缚水与自由水比值随干旱加剧而增大 ,叶片维持较高的含水量 ,蒸腾减弱 ,叶水势降低 ,临界饱和亏增大 ,表现出较强的抗旱性。(2 )沙棘光合速率具明显的日变化 ,10 :0 0 12 :0 0出现第 1次峰值 ,14 :0 0 15 :0 0出现第 2次峰值。沙棘光合速率与环境因子 (气温、相对湿度和光合有效辐射 )间有显著的相关关系 ,相关系数为 0 .84 6 6 0 .935 1,其中光合有效辐射对光合速率影响最显著 ,气温次之 ,相对湿度最小 ;沙棘光合速率与气孔导度及细胞间CO2 浓度间有十分显著的相关关系 ,相关系数为 0 .985 2 0 .985 6。(3)沙棘蒸腾速率与气孔导度具明显的日变化 ,两者的变化趋势相似 ,5、7月日变化曲线呈单峰型 ,6、8、9月日变化曲线呈双峰型。在生长季 (5 9月 )中 7月蒸腾速率最大 ,5、9月较小 ,5月(0 .39g·g- 1·h- 1)仅为 7月 (0 .93g·g- 1·h- 1)的 4 1.93%。黄土丘陵区安塞的环境条件基本满足沙棘生长的要求 ,沙棘可作为该地区造林恢复植被的先锋树种。这为沙棘的?
In order to investigate the adaptability of seabuckthorn to the water conditions in semi-arid loess hilly region, the hydrophyte ecology and drought resistance of seabuckthorn were studied in 1998. The results showed that: (1) The seabuckthorn adapts to the semi-arid loess hilly region habitat to form a drought-resistant and drought-resistant double drought-resistant way. In the dry season, the bound water content of seabuckthorn increased with the increase of drought, and the ratio of irreducible water to free water increased with the increase of drought. The leaves maintained high water content, decreased transpiration, decreased leaf water potential and increased critical saturation loss Strong drought resistance. (2) The diurnal variation of photosynthetic rate of seabuckthorn was obvious. The first peak appeared at 10:01 0:01 and the second peak appeared at 14:00 0:15. There was a significant correlation between photosynthetic rate of seabuckthorn and environmental factors (temperature, relative humidity and photosynthetically active radiation), the correlation coefficient was 0.84 6 6 0. 935 1, of which photosynthetic active radiation had the most significant effect on photosynthetic rate, , And the relative humidity was the lowest. There was a significant correlation between photosynthetic rate and stomatal conductance and intercellular CO2 concentration in seabuckthorn with the correlation coefficient of 0.9850 20.9856. (3) The diurnal variation of transpiration rate and stomatal conductance of Hippophae rhamnoides L. had obvious diurnal variation. The trend of both was similar. The diurnal variation curve of diurnal variation in May and July showed a single peak, while the diurnal variation curves of diurnal variation in June, August and September presented a bimodal pattern. The transpiration rate in July was the largest in the growing season (September-September), but was smaller in May and September than in July (0.39g · g-1 · h-1) in July (0.93g · g-1 · h- 1) 4 1.93%. The environmental conditions of Ansai in the loess hilly area basically meet the requirements of seabuckthorn growth. Seabuckthorn can be used as the pioneer tree species for afforestation and restoration in this area. Is this seabuckthorn?