摘要
测定辽东栎叶在不同发育时期的长度 ,面积和干重 ,应用红外 CO2 技术测定叶的净光合速率和暗呼吸速率的季节变化和日变化 ,并根据叶的平均生长速率和净光合速率推算叶生长过程中碳的输入和输出的变化趋势。结果表明 :( 1 )辽东栎叶的长度、面积和干重的增加有共同趋势 ,即在叶生长早期增加很快 ,其后渐渐降低。叶长度、面积约在 6月初达极大值 ;叶干重稍后达极大值。 ( 2 )净光合速率在整个生长季里随叶的生长发育是先上升 ,至 7月中旬达极大值 ,然后逐渐下降 ;而暗呼吸速率除在落叶前有微弱上升外 ,一直都处在下降状态。 ( 3 )叶的净光合速率日进程具“午休”现象 ,可能由高温和强光照引起。 ( 4)叶的形成初期 ,碳的输入较高 ,展叶后约 1 0 d左右 ,输入输出达到平衡 ;碳输出在 7月中旬达极大值 ,随后下降。 ( 5)
Leaf length,area and weight were measured for Quercus liaotungensis in different stages of leaf development,and the infra red CO 2 technique was applied to measure the seasonal and diurnal rate of net photosynthesis and dark respiration.Based on the mean rate of leaf growth and net photosynthesis,the tendency of carbon transition was also estimated.The results showed that (1) the accretions of leaf length,area and weight had a common tendency of rapid increase in the early stage of leaf expansion.Leaf length and area reached their maxima in early June,shortly after which leaf dry weight also reached the maximum;(2) The rate of net photosynthesis increased in the early stage,and reached its peak in mid July,subsequently declined;while the rate of dark respiration declined during leaf development except a slight rise before abscission;(3) The 'noon rest' of net photosynthesis rate in the diurnal variation might be caused by high temperature or high light intensity;(4) Leaf carbon import was relatively high in the early stage of development,and approximated to zero at the tenth day of leaf expansion.Carbon export reached its maximum in mid July.and subsequently declined.It could be concluded that (5) leaf photosynthesis capacity had a close relation to development stage.
出处
《生态学报》
CAS
CSCD
北大核心
2000年第2期212-217,共6页
Acta Ecologica Sinica
基金
中国科学院重点资助项目 !( KZ951 -SI-2 1 )
关键词
辽东栎
叶
生长
光合作用
Quercus liaotungensis
leaf growth
photosynthesis
