多重情景下半干旱地区人工杨树林光合生理特征

深刻剖析多重情景下主要防风固沙树种的光合生理特征,对半干旱地区生态系统的健康维持与恢复重建具有重要的指导意义。以半干旱典型区科尔沁沙地人工杨树为研究对象,采用Li-6400红外气体分析仪活体测量生长季不同月份、嫩叶与成熟叶、上午与下午以及不同CO2浓度和光强下杨树叶片的光响应和CO2响应曲线,进一步对比分析这些情景下净光合速率(Pn)、蒸腾速率(Tr)和水分利用率(WUE)的差异性。结果表明:在相同光强和CO2浓度下,生长旺盛期杨树叶片的Pn高于生长初期和生长末期;嫩叶与成熟叶的Pn、Tr、WUE差异明显,嫩叶的蒸腾作用相对较强,成熟叶的光合作用相对较强。研究结果对开展半干旱地区人工杨树光合生理相关研究具有一定的参考价值。

Photosynthetic Physiological Characteristics of Artificial Populus in Semi-arid Area Under Multiple Scenarios

Fully analyzing the photosynthetic physiological characteristics of the main sand-fixing species in multiple scenarios has important scientific meanings for the maintenance and reconstruction of the ecosystem. The artificial Populus of Horqin Sandy Land was selected as the test materials to measure the light response and CO₂ response curves by using Li-6400 infrared gas analyzer. The testing scenarios included comparison across different months, tender and mature leaves, morning and afternoon, as well as different CO₂ concentrations and light intensity environments. Further, the net photosynthetic rate (P_n), transpiration rate (T_r) and water use efficiency (WUE) were analyzed. The results indicated that:Under the same light intensity and CO₂ concentration, the P_n at vigorous growth period was larger than that at the initial and late growth periods. The P_n, T_r and WUE were significantly different by comparing tender and mature leaves, the transpiration of tender leaves was relatively stronger, while photosynthesis of mature leaves was relatively stronger. These findings provided main reference value for the study of the physiology of artificial Populus in semiarid areas.