阿拉善白刺生长季叶片尺度耗水特性

The Characteristics of Water Consumption of Blade Scale for Nitraria tangutorumin Alxa League

为优化水资源的配置,恢复或重建生态系统,以便在干旱、半干旱地区改进抗旱节水造林技术,对阿拉善盟白刺群落生长季叶片尺度耗水特性进行测定了分析。结果表明:(1)白刺生长季水分利用效率日变化最高值出现在上午,5、6、9、10月在10:00左右达最大值,而7、8月在8:00左右达最大值,最小值出现在早、晚。月变化为9、10月最大,其次7、8月,5、6月最小。其中月均值10月>9月>7月>8月>6月>5月。(2)整体上光合速率上午比较强,而蒸腾速率上午呈现上升趋势,在中午达最大值,下午二者都呈现递减趋势。(3)生长季各月叶片水势与蒸腾速率呈相反趋势。(4)白刺蒸腾耗水主要是消耗深50cm土壤附近的水。

In order to optimize the allocation of water resources and to restore and reconstruct the ecosystem,so as to improve the drought-resistant and water-saving afforestation technology in arid and semi arid areas.The characteristics of water consumption at the blade scale of Nitraria tangutorumcommunity in Alxa League were analyzed.Result shows that:1)The diurnal variation of water use efficiency in the growth season is the highest in the morning and the lowest in the morning and evening,the trend of change reach the maximum value at 10:00 in May,June,September and October;water use efficiency in the 8:00 or so in July and in August reach the maximum.The water use efficiency of Nitraria tangutorumis the highest in September and October,followed by July and August,and the minimum is May and June.The descending of monthly water use efficiency is October> September> July>August> June> May.2)The overall photosynthetic rate is relatively strong in the morning,while the transpiration rate is increasing in the morning,and the plant transpiration rate reach the maximum at noon.Both in the afternoon show a decreasing trend,that is,photosynthesis weaken,transpiration weaken.3)The relationship between leaf water potential and transpiration rate during the growing season is significant.4)Transpiration water consumption of Nitraria tangutorumis mainly in the depth of 50 cm soil layer.