广西地区常见棕榈科植物光合特性研究

以广西南宁市不同棕榈科植物（棕竹、蒲葵、槟榔）为试材，研究和比较了其光合特性。结果表明:不同棕榈科植物株高、茎粗和冠幅均表现为槟榔 > 蒲葵 > 棕竹，叶面积指数和比叶重均表现为蒲葵 > 槟榔 > 棕竹，根区土壤pH表现为棕竹 > 槟榔 > 蒲葵，根区土壤养分大致表现为蒲葵 > 槟榔 > 棕竹，局部有所波动，其中不同棕榈科植物根区有机碳含量差异不显著（p > 0.05）。不同棕榈科植物光饱和点（LSP）、光补偿点（LCP）、表观量子产额（AQY）、羧化效率（CE）、气孔限制值（L_s）、水分利用效率（WUE）、光合氮利用效率（NUE）和光合磷利用效率（PUE）基本表现为蒲葵 > 槟榔 > 棕竹，局部有所波动，与叶面积指数和比叶重以及其根区土壤养分变化趋势相一致，其中不同棕榈科植物L_s差异不显著（p > 0.05）。不同棕榈科植物一天各时期净光合速率（P_n）、蒸腾速率（EVAP）、气孔导度（G_s）和胞间CO₂浓度（C_i）基本表现为蒲葵 > 槟榔 > 棕竹规律，净光合速率（P_n）日变化均呈双峰曲线，气孔限制导致了光合“午休”现象，胞间CO₂浓度（C_i）、气孔导度（G_s）和蒸腾速率（EVAP）日变化随时间呈“W”变化规律。通过SPSS最佳曲线拟合不同棕榈科植物的P_n与PAR，CO₂浓度和温度变化呈一致的二次曲线关系。相关性分析表明，不同棕榈科植物光合特性由多种因素共同决定，这些因素之间也会相互影响，其中G_s的相关系数较大。

Research on Photosynthetic Characteristics of Common Palmae Plants in Nanning City

Photosynthetic characteristics, physiological property and the main influence factors of common Palmae plants (Rhapis Excelsa, Livistona chinensis and Areca catechu) were investigated comparatively in Nanning City. The results showed that: (1) the plant heights, stem diameters and crown breadths of different Palmae plants decreased in the order: Areca catechux > Livistona chinensis > Areca catechu, leaf area indexes and specific leaf weights decreased in the order: Livistona chinensis > Areca catechu > Rhapis excelsa, pH levels of the root zone soil decreased in the order: Rhapis excelsa > Areca catechu > Rhapis excelsa, and the nutrient contents of the root zone soil decreased in the order: Livistona chinensis > Areca catechu > Rhapis excelsa with local fluctuation, and there was no significant difference of soil organic carbon in common Palmae plants (p > 0.05); (2) the light saturation point (LSP), light compensation point (LCP), apparent assets (AQY), carboxylation efficiency (CE), stomatal limitation (L_s), water use efficiency (WUE), nitrogen use efficiency (NUE) and phosphorus use efficiency (PUE) of three common Palmae plants decreased in the order: Livistona chinensis > Areca catechu > Rhapis excelsa with local fluctuation, which there was no significant difference of Ls of common Palmae plants (p > 0.05), and this variation tendency was the same as the root zone soil nutrients; (3) the responsive curves of photosynthesis in three kinds of Palmae plants to the change of photosynthetic rate (P_n), transpiration rate (EVAP), stomatal conductance (G_s), intercellular CO₂ concentration (C_i) with the Livistona chinensis was the highest and the Rhapis excelsa was the lowest, while stomatal limitation resulted in different levels of photosynthetic ‘lunch break’ phenomenon, and transpiration rate (EVAP), stomatal conductance (G_s), intercellular CO₂ concentration (C_i) of three kinds of Palmae plants showed the W-shape; (4) the change of photosynthetic active radiation (PAR), CO₂ concentration and air temperature of three kinds of Palmae plants could be described with quadratic equations (P<0.001); (5) correlation analysis showed that photosynthetic characteristics and physiological properties of Palmae plants were determined by a variety of environmental factors, and these factors could be influenced each other, and among these environmental factors, the absolute value of correlation coefficient of G_s was the greatest.