北京六个绿化树种盆栽蒸腾耗水量的比较研究

采用BP3400精密天平和Lico-6400便携式光合系统等仪器研究了北京6个城市绿化树种在不同密度下的耗水量及耗水速率的日变化和昼夜变化状况.结果表明，在正常水分条件下，各树种苗木耗水量和耗水速率的日变化规律呈“单峰型”变化，峰值出现在10:00—14:00之间.各树种在单株密度时日平均耗水量大小排列是:国槐＞白蜡＞侧柏＞油松＞丁香＞黄杨;日平均耗水速率的大小为:白蜡＞国槐＞丁香＞黄杨＞侧柏＞油松.阔叶树种的耗水速率明显大于针叶树种.随着密度的增加，各种苗木的耗水量是递增的，耗水速率是递减的.6种苗木随着密度增加日平均耗水速率下降幅度是:油松最大，国槐最小，白蜡、侧柏、丁香和黄杨居中. 

Comparison of transpiration of six potted afforestation species in Beijing.

Daily changes of transpiration rate of six tree species for city greening in Beijing and water consumption status in different densities were studied by using Lico-6400 and BP3400 and press chamber etc. Then day and night variation and the daily variation of water consumption potential of the six tree species and the factual water consumption rate were compared. The results show that the rules take on “single peak style” in normal water supply, and the peak value appears between ten o’clock and fourteen. When the density is one, these six species have the average transpiring water consumption amount in the following order: Sophora japonica＞Fraxinus velutina＞Platycladus orientalis＞Pinus tabulaeformis＞Syringa oblata＞Buxus sinica. The average transpiring water consumption rateis in the following order: Fraxinus velutina＞Sophora japonica＞Syringa oblata＞Buxus sinica＞Platycladus orientalis＞Pinus tabulaeformis. And the transpiring water consumption rates of broad-leaf tree species are much greater than coniferous species. With the increase of the density, water consumption amount increases quickly but the water consumption rate decreases. With the increase of the density, the average transpiring water consumption rate of the six species is in the following descending order: Pinus tabulaeformis is the largest, while Sophora japonica is the smallest, and Fraxinus velutina, Platycladus orientalis, Syringa oblata, Buxus sinica are in the middle.