5种园林树木的光合和蒸腾特性的研究

本文测定 5种常见园林树木 (金银木、紫薇、皱叶荚迷、核桃、金叶接骨木 )的光合、蒸腾特性 结果表明 :5种树木夏初晴天均有明显的光合速率日变化 ,耐荫性较差的树种中午前后光合作用有显著的“午休”现象 ,这主要是气孔导度下降引起 ,光合速率与叶绿素含量无关 ,5树种的耐荫性从强到弱依次为 :金银木、紫薇 >皱叶荚迷 >核桃 >金叶接骨木 ;核桃的蒸腾速率属午后高峰型 ,金银木属午前高峰型 ,金叶接骨木耗水量最大 ,蒸腾速率主要受光合有效辐射、叶温和气孔导度等因素的影响

Studies on the Characteristics of Photosynthesis and Transpiration of Five Gardening Trees

The characteristics of photosynthesis and transpiration of five gardening trees (Lonicera maackii,Lagerstroemia indica,Viburnum rhytidophyllum,Juglans regia,Sambucus camadensis) were measured in the field in sunny early summer days.The diurnal variation of the photosynthetic rate(Pn) of these five trees were significant,obvious midday decrease of the Pn appeared in the lower shade-tolerance trees,which was mainly induced by the decrease in stomatal conductance,the Pn was independent on chlorophyll content,the shade-tolerance of the 5 trees in the order from high to low was: L.maackii,L.indica>V.rhytidophyllum>J.regia>S.camadensis. The highest transpiration rate of J.regia appreared in the afternoon,and L.maackii in the forenoon,the were consumption quantity of S.Camadensis was highest,the photosynthetic active radiation,leaf temperature and stomatal conductance were the dominant factors affecting transpiration.