中文摘要：

为了揭示黄河三角洲盐碱地混交林不同树种的光合特性，探寻适宜的混交林优势树种，利用CIRAS-1型便携式光合仪测定黄河三角洲盐碱地6种常见树木（桑树、刺槐、白蜡、苦楝、杨树和国槐）的光合速率、蒸腾速率、光合有效辐射及气孔导度。结果表明：6种树木4项指标峰值大部分出现在10：OO和14：00；杨树和国槐光合速率和光合有效辐射日变化为双峰曲线，桑树的蒸腾速率为双峰曲线，其余树种四项指标为单峰曲线；影响6种树木光合速率的因子依次是光合有效辐射〉叶温〉气孔导度，而蒸腾速率则是气孔导度〉光合有效辐射〉叶温；杨树、国槐和刺槐的光合速率、蒸腾速率等指标值较高，相较于其它树种差异达到显著水平（P〈O．05）。

英文摘要：

In order to reveal the photosynthetic characteristics of different trees in mixed forest of saline-alkali soil in the Yellow River Delta and search for regnant trees,this study used CIRAS-1 type portable photosynthetic apparatus to research the char acteristics of photosynthetic rate, transpiration rate, photosynthetic active radiation, and stomatal conductance of six kinds of common saline-alkali soil trees（ Morus alba L, Black Locust, Fraxinus chinensis Roxb, Melia azedaeach L, P. ussuriensis, Sophora japonica Linn）. The results showed that the maximum of photosynthetic rate,transpiration rate, photosynthetic active radiation,and stomatal conductance mostly appeared at 10：00 or 14：00. Photosynthetic rate and photosynthetic active radiation of P. ussuriensis and Sophora japonica Linn were bimodal curve. Transpiration rate of Morus alba L was bimodal curve. However,four indexes of the other trees were unimodal curve. The order of the factors influencing photosynthetic rate was photosynthetic active radiation〉 leaf temperature〉 stomatal conductance, while for transpiration rate, the order was stomatal conductance〉photosynthetic active radiation〉leaf temperature. Black Locust, P. ussuriensis, and Sophora japonica Linn had higher value in photosynthetic rate and transpiration rate, photosynthetic active radiation, stomatal conductance, and they had more significant differences than others.