滨海围垦地红叶椿光合特性研究

采用Li-6400便携式光合仪，研究了上海南汇区围垦地生长的红叶椿（Ailanthus altissima CV．Hongye）光合特性日变化。结果表明：（1）在自然光照条件下，红叶椿光合速率呈单峰型日变化曲线，在中午时分达到最大值11．58μmol／m^2.s；（2）净光合速率与光合有效辐射、蒸腾速率、气孔导度呈正相关关系，与胞间CO2浓度、相对湿度呈负相关关系；（3）光补偿点和光饱和点分别为31．78μmol/m^2·s和1365．11μmol／m^2．s,红叶椿为喜光植物。光合有效辐射，蒸腾速率是影响净光合速率的主要因子。

Photosynthetic Characteristics of Ailanthus altissima cv. Hongye in Coastal Reclamation Land

The diurnal-variations of photosynthetic characteristics of Ailanthus altissima cv. Hongye growth in reclamation land in Nanhui District of Shanghai were studied by Li-6400 portable photosynthetic system. The results showed that: under the natural illumination condition, the photosynthetic rate of Ailanthus altissima cv. Hongye showed a single peak diurnal variation curve, which reached maximum value of 11.58 μmol/m~2·s at noon; there were positive correlations between net photosynthetic rate and photosynthetically active radiation, transpiration rate and stomatal conductance, but there were negative correlations between net photosynthetic rate and intercellular CO_2 concentration and relative humidity; the light compensation point and light saturation point of Ailanthus altissima cv. Hongye were 31.78 μmol/m~2·s and 1 365.11 μmol/m~2·s, respectively. Ailanthus altissima cv. Hongye is a kind of heliophilous plant,the Net photosynthetic rate was mainly affected by photosynthetically active radiation and transpiration rate.