摘要
研究了樟树叶片蒸腾速率的日变化和季节变化特征,估算了其水分利用效率,并建立了蒸腾速率、水分利用效率与生理生态因子的响应模型.结果表明:(1)蒸腾速率日变化均表现为单峰型曲线,不同生长季节不同部位叶片蒸腾速率的大小不同,5月和9月蒸腾速率大小顺序为上部叶>中部叶>下部叶,7月蒸腾速率大小顺序中部叶>上部叶>下部叶.(2)在整个生长期,以生长中期中部叶的蒸腾速率为最高,达到6.72 mmol.m-2s-1.(3)蒸腾速率季节变化也表现为单峰曲线,6月蒸腾速率较高,其中上部叶为3.72 mmol.m-2s-1,中部叶为2.31 mmol.m-2s-1,下部叶为2.93 mmol.m-2s-1.(4)对樟树生长时期的不同部位叶片的蒸腾速率与生理生态因子进行分析,光合有效辐射(PARi)、气孔导度(Cond)、空气温度(Tair)和叶面水汽压亏缺(Vpdl)对蒸腾速率贡献较大,光合有效辐射对上部叶片的蒸腾速率贡献较中下部大.(5)叶片的水分利用效率5月份和9月份大小排序为下部叶>上部叶>中部叶;7月份为下部叶>中部叶>上部叶.叶片水分利用效率与气温(Tair)、叶面温度(Tleaf)和胞间CO2浓度(Ci)的相关性较高.
The paper studied the diurnal and seasonal variations of the transpiration rates of Cinnamomum camphors (L.) Presl leaves, estimated their water using efficiency and set up some response models for the transpiration rate, water using efficiency and physio-ecological factors. Results show that the diurnal variation of its transpiration rate takes on a single peak curve and the rate in different parts of the leaves in different growing seasons is different; that in May and September, the order of transpiration rate is upper leafy〉middle leafy〉low leaf while in July it is middle leafy〉upper leafy〉low leaf; that throughout its growing season, the transpiration rate of middle leaf in medium-term growth is the highest, being 6. 72 mmol·m^-2s^-1; that the seasonal variation of transpiration rate also assumes a single peak curve with the peak value in June and the transpiration rate of upper, middle and low leaf is 3. 72 mmol·m^-2s^-1, 2. 31 mmol·m^-2s^-1 and 2. 93 mmol·m^-2s^-1 respectively; and that analyses of the transpiration rates in different parts of the leaves in different growing seasons and of its physio-ecological factors prove that photo-synthetically active radiation (PARi), stomatal conductance (Cond), air temperature (Tair) and vapor pressure deficit on leaf area (Vpd1) all have great contributions to the transpiration rates. The water using efficiency in leaf takes on an order of low leaf〉upper leaf〉middle leaf in May and September and an order of low leaf〉middle leafy〉upper leaf in July. There are significant correlations between water using efficiency in leaf, and air temperature (Tair), leaf temperature (Tleaf) and intercellular CO2 concentration (Ci).
出处
《中南林业科技大学学报》
CAS
CSCD
北大核心
2009年第1期1-5,共5页
Journal of Central South University of Forestry & Technology
基金
国家林业局项目(2007-4-19
2008430
2007-4-15)
国家自然科学基金(30870455
30771700
30571487)
湖南省科技厅项目(07JJ1004
06FJ3083
2007SK4030
2007FJ4046
05NK3026)资助
关键词
植物生理学
樟树
蒸腾速率
水分利用效率
生理生态因子
phytophysiology
C. camphora (L.) Presl
transpiration rate
water using efficiency
physio-eeological factor