半红树植物苦郎树光响应模型拟合及 光合特性研究

Fitting of Light Response Model and Photosynthetic Characteristics of Semi- Mangrove Plant Clerodendrum inerme

摘要:

苦郎树是一种沿海防沙固堤的半红树植物，不仅在红树林群落中具有重要的生态价值，叶片提取物还有一定的医药价值。本研究通过4种光响应模型对苦郎树光响应曲线拟合，计算光合参数进行对比分析，评估最适拟合模型，并研究其光合特性。结果表明：不同模型对苦郎树光响应拟合存在差异，四种模型拟合优度均在0.996以上，苦郎树气孔导度随光合辐射增加而增加，在1800 μmol·m-2·s-1有效光合辐射下达到最大；在500 μmol·m-2·s-1有效光合辐射下水分利用效率最高，胞间二氧化碳维持在一个不变的浓度，与大部分植物的光合特性相似。非直角双曲线模型对苦郎树拟合效果最佳，如何精确拟合光饱和点还需进一步研究，应需要根据实际情况选用最适宜的光响应拟合模型，为海岸生态、防风固堤和园林绿化等工作提供理论依据。

Abstract:

Clerodendrum inerme is a semi-mangrove plant for coastal sand prevention and embankment reinforcement. It not only has important ecological value in mangrove community, but also has medical value. In this study, four light response models were used to fit the light response curve, calculated the photosynthetic parameters, then compared and analyzed, evaluated the best fitting model, and studied its photosynthetic characteristics. The results showed that there were differences in fitting the light response of C. inerme by different models. The goodness of fit of the four models were more than 0.996, the stomatal conductance of C. inerme increased with the increase of photosynthetic radiation, and the stomatal conductance was the largest when the photosynthetic radiation was 1800 μmol·m-2·s-1. When photosynthetic radiation was 500 μmol·m-2·s-1, the water use efficiency was the highest, and the intercellular CO2 remained at a constant concentration, which was similar to the photosynthetic characteristics of most plants. The fitting effect of the Non-rectangular hyperbola model was the best for C. inerme. Further research is needed to accurately fit the light saturation point. The most suitable light response fitting model should be selected according to the actual situation. It provides a theoretical basis for coastal ecology, windbreak and Embankment Consolidation and landscaping.