摘要
对旱生植物沙拐枣、梭梭和中生植物杨树、沙枣在干旱胁迫下的水分生理特性进行了比较研究.结果显示, 4种植物均表现出不同程度的水分亏缺,并且具有明显的日变化,其中中生植物沙枣、杨树的水分亏缺日变化表现为大起大落.梭梭的水势低于其他3种植物,低水势有利于植物从土壤吸收水分,增强植物抗旱性.沙枣、沙拐枣的蒸腾速率日变化分别为双峰型和单峰型,而梭梭和杨树表现为平缓型. 4种植物在整个蒸腾速率日变化过程中,环境因子起主导作用. 4种植物的水分利用率日平均值依次为沙拐枣>沙枣>梭梭>杨树.沙拐枣比梭梭能更有效地利用水分,尽管梭梭的水分利用效率低于沙拐枣,但其具有较低的水势和蒸腾速率,具有很强的水分吸收和减少水分丧失的能力,因此,相对而言也适宜在干旱的沙漠生境中生存.尽管沙枣的水分利用率较高,但因其具有较高的蒸腾和较大的叶面积,因此更适合于水分较好的荒漠生境,是主要的防护林树种.
The water physiological features of Haloxylonammodendron, Calligonum and Populus hosiensis, Elaegnusn Angastifolia under drought stress were comparatively studied. The results indicated that the four kinds of plants all showed water saturated deficiency to different degree and have obvious diurnal changes, in which water saturated deficiency of Populus hosiensis and Elaegnusn Angastifolia fluctuated greatly. Water potential of Haloxylonammodendron was lower than that of other three species, which was helpful to absorb water from soil and to increase anti-drought abilities. The diurnal changes of transpiration rates of Calligonum and Elaegnusn Angastifolia showed two-peaked type and one-peaked type respectively, whereas that of Haloxylonammodendron and Populus hosiensis fluctuated gently. Diurnal fluctuations of transpiration rate of four kind plants were all mainly controlled by environmental factors. Water use efficiency of Calligonum was higher than that of other three species. Although Calligonum can use water more efficiently than Haloxylonammodendron , the latter has higher ability to absorb water and to minimize water loss due to its lower transpiration and lower water potential. Elaegnusn Angastifolia took on comparably high water use efficiency. However, high transpiration and large leaf area made it more suitable for desert habitat with good water condition and be an important species for protection forest.
出处
《北京师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2005年第2期194-198,共5页
Journal of Beijing Normal University(Natural Science)
基金
国家重点基础研究发展规划资助项目(G2000018600
G2000048704)
关键词
荒漠植物
干旱胁迫
蒸腾速率
水分利用效率
desert plants
drought stress
transpiration rate
water use efficiency
