【摘要】 基于环境舒适度的温湿度变幅条件下,利用LI—6400XT便携式光合测定仪,对北京市居住区绿地中常见的国槐、银杏、垂柳等8优势树种进行了光合特性的测定。结果表明:温湿度的变化对8种园林植物的光合速率、蒸腾速率、气孔导度和胞间CO₂浓度有明显的影响,但是光合特性各指标对温湿度变化的适应性各不相同:在湿度一定的情况下,大多数植物的光合速率、蒸腾速率、气孔导度、胞间CO₂浓度随着温度的升高呈单峰曲线;其四种特征值的最高峰值大多出现在温度25℃,湿度在60%⁸0%左右的组合水平条件下。在温度一定的情况下,大多数植物的光合速率、蒸腾速率、气孔导度、胞间CO₂浓度随着湿度的升高没有明显的变化规律。但可以看出湿度在60%⁸0%水平对大多数树种来说四种光合特征值均影响较大。经温度与湿度的双因素统计分析结果表明:大多数树种在温度25℃,60%⁸0%的湿度水平下时光合特征值显著高于其它几个水平值,且超过60%以上的树种两种因素的交互作用显著。更多还原

【Abstract】 Based on the range of temperature and humidity of environmental comfort degree,we determined photosynthetic characteristics of eight dominant tree species in Beijing residential green space by using LI—6400XT portable photosynthesis system. Our results show that the change of temperature and humidity has an significant influence on thephotosynthetic rate,transpiration rate,stomatal conductance and intercellular CO₂ concentration,but each index of the photosynthetic characteristics has different adaptability to the changes of temperature and humidity: When humidity stay the same,most plants’ photosynthetic rate,transpiration rate,stomatal conductance and intercellular CO₂ concentration show unimodal curve with the increase of temperature; also the highest peak value to the four kinds of characteristic will reach to 25 ℃,and the humility level will attain the combination level round 60% 80%. While if the the temperature stay the same,the four characteristics have no obvious changing regulars with the temperature increasing. However,what can be clear is when the humidity is in the level of 60% 80%,for most species,the four kinds of photosynthetic characteristic values are badly influenced. According to the statistical analysis of temperature and humidity,We find that under the condition 25 ℃ and humility level of 60% ⁸0%,the photosynthetic characteristic values of most tree species will be significantly higher than others,and more than 60% tree species have significant interactions between temperature and humidity.更多还原