摘要
通过对 5 0年生栓皮栎天然次生林叶片的活体测定 ,研究了CO2 浓度增长对栓皮栎林光合生理生态特性的影响 .结果如下 :CO2 浓度为 80 0 μmolCO2 ·mol- 1 时栓皮栎叶片的净光合速率比在正常大气CO2 条件下提高 42 .5 3 % ,同时光补偿点降低 ,光饱和点提高 ,光量子效率提高 ;CO2 浓度为 80 0 μmolCO2 ·mol- 1 时 ,栓皮栎净光合速率的日变化为单峰曲线 ,而CO2 浓度为40 0 μmolCO2 mol- 1 时 ,净光合作用的日变化为双峰曲线 ;CO2 浓度倍增 ,栓皮栎叶片的气孔导度 ,蒸腾速率和暗呼吸速率降低 ,水分利用效率显著提高 .栓皮栎叶片对CO2 增长的反应 ,对其生长是有利的 ,对全球CO2 浓度增长起到反馈调节作用 .
The net photosynthesis( Pn ),the daily courses of Pn ,transpiration rate( TR ),stomatal conductance( COND ),water use efficiency( WUE )and dark respiration( DR )of Quercus variabilis under ambient and elevated CO 2 conditions were determined with Licor-6400 photosynthesis system.The results are as follows (1) Compared to the ambient air CO 2 concentration(400 μ mol CO 2·mol -1 ), Pn and quantum efficiency under 800 μ mol CO 2·mol -1 were significantly increased.Furthermore,the light compensation point decreased while light saturation point elevated.(2)The daily courses of Pn under ambient CO 2 concentration were double peaked,however under 800 μ mol CO 2·mol -1 they were single peaked.(3) Under elevated CO 2(800 μ mol CO 2·mol -1 ), COND,TR and DR reduced,and WUE increased significantly.It was concluded that the increasing CO 2 concentration in the atmosphere would be beneficial to Quercus variabilis and the Quercus variabilis forest would slow down the pace of CO 2 increase.
出处
《西南林学院学报》
2002年第1期1-4,共4页
Journal of Southwest Forestry College
基金
国家自然科学基金资助项目 ( 39899370 )
关键词
栓皮栎
净光合速率
气孔导度
蒸腾速率
暗呼吸
二氧化碳增长
elevated CO 2
Quercus variabilis
net photosynthetic rate
stomatal conductance
transpiration rate
dark respiration
