不同保水处理下苏丹草光合特性研究

为了研究矿区生态修复过程中植物对不同保水措施的生理响应,以常用修复植物苏丹草为研究对象,利用CIRAS-2型(PP-Systems)光合仪测定苏丹草的光合指标,探讨高温下苏丹草对不同保水措施的生理响应,以期为矿区生态修复中的保水措施提供理论依据。结果表明：不同保水处理下苏丹草的光合速率Pn和瞬间水分利用效率WUE日变化均呈“W”型曲线,蒸腾速率Tr日变化呈“M”型曲线。苏丹草的Pn有“午休”现象存在,主要受非气孔因素的影响。影响苏丹草Pn、Tr的主要环境因子为大气CO₂浓度Ca、大气温度Tc、大气相对湿度RH。在土壤上覆盖火烧石和添加粉煤灰均显著增大了苏丹草的Pn和WUE,增强了苏丹草适应高温环境的能力。从Pn的指标来看,土壤表面覆盖火烧石处理比土壤中添加粉煤灰处理的效果好,但两者同时作用效果略低于单独用火烧石处理,原因有待进一步研究。

Photosynthetic Characteristics of Sorghum sudanense Under Different Water-retaining Treatments

To study the physiological response of plants to different water-retaining measures in ecological restoration of mining area, the authors used CIRAS-2 (PP-Systems) photosynthesis instrument to determine the photosynthetic index of Sorghum sudanense, which often used to repair plant, and discussed the physiological response of Sorghum sudanense to different water-retaining measures under high temperature. The results showed that the daily change of photosynthetic rate Pn and instantaneous water use efficiency WUE presented a “W” curve, and the Tr diurnal change of transpiration rate was a “M” curve. The Pn of Sorghum sudanense had the phenomenon of lunch break, which was mainly affected by non-stomatal factor. The main environmental factors affecting the Sorghum sudanense Pn and Tr were atmospheric CO₂ concentration Ca, atmospheric temperature Tc and atmospheric relative humidity RH. Covering burning stone on the soil and adding fly ash could both significantly increase the Pn and WUE of Sorghum sudanense and enhance the adaptability of Sorghum sudanense to high temperature environment. From the index of Pn, the treatment of soil surface covered with burning stone was better than the treatment of adding fly ash in soil, but the effect of the both at the same time was slightly lower than that of using burning stone alone, and the reason needs to be further studied.