黄土丘陵沟壑区狼牙刺的蒸腾作用研究

对狼牙刺和柠条的蒸腾日变化、月变化作了动态测定,研究了狼牙刺的蒸腾特性及其同环境因子及土壤水分之间的关系。结果表明:(1)狼牙刺和柠条的蒸腾速率日变化基本是以单峰型曲线为主,少数为双峰型。在10:00~14:00时段是狼牙刺和柠条的高速蒸腾期;蒸腾极大值多出现在12:00。(2)从6~9月份,狼牙刺和柠条的蒸腾速率呈逐月下降趋势,不同林龄狼牙刺之间的蒸腾速率月均值差异不明显,但狼牙刺与柠条的蒸腾速率月均值的种间差异比较明显,即柠条的蒸腾作用略高于狼牙刺。(3)一天当中,狼牙刺的蒸腾速率与光合有效辐射、空气温度密切正相关,与大气湿度负相关;6~9月,狼牙刺蒸腾速率的日均值与土壤水分状况密切正相关。(4)在黄土丘陵沟壑区进行人工林草植被建设过程中,应该主要充分了解物种在6、7月份(林木生长旺盛期)的耗水特点及土壤供水能力,以保证植被的快速恢复。

Study on the transpiration of Sophara viciifolia in the hilly and gully Loess Plateau

Based on the measurements of the diurnal and monthly transpiration rate, the characteristics of transpiration of Caragana korshinskii Kom and Sophara viciifolia Hance and the relationship between transpiration and environmental factors and soil water were studied. The following conclusions can be drawn: the curves of the diurnal variations of transpiration rate in Sophara viciifolia Hance and Caragana korshinskii Kom show one-peak type mainly, their highest transpiration rate occurred in period of 10: 00~14: 00;The transpiration rate of Sophara viciifolia Hance and Caragana korshinskii Kom decreases gradually from June to September, there is no big difference with the average value of monthly transpiration among the different age's Sophara viciifolia Hance, but the transpiration rate of Sophara viciifolia Hance is higher than Caragana korshinskii Kom from June to September;the curves of diurnal variation of transpiration rate in Sophara viciifolia Hance has a positive correlation with PAR and air temperature and has a negative correlation with air humidity;the seasonal changes of transpiration rate has a close relation with the content of soil water. As a result, we should know the plant's water-consumption and the ability of soil' s water supply in the process of vegetation reconstruction in the hilly and gully loess area to ensure the vegetation restoration.