摘要
The ICT\|2000TE meteorological measurement system was used to determine the transpiration rate of Cinnamomum camphora and the variation of main ecological factors around canopy layer.The results indicated that under full light condition in sunny days, a single peak curve was found in the daily variation of radiation and temperature around canopy layer. The radiation started to increase at 6:00 am and reached the peak of 150~800 μmol·m -2 s -1 at 12:00 , then declined to 0 at 18:00? ?0:00pm. The summer had the high variation and long time of radiation. Temperature reached the peak at 15:00—17:00. However, the daily change of humidity showed a reverse tendency in comparison with that of radiation and temperature. The humidity began to decrease at 6:00 and slumped to the lowest at 15:00 and then increased. The daily change of transpiration rate of C. camphora was found in the form of single peak curve and the highest value occurred at 14:00. The highest transpiration rate of 0.503 1 L·kg -1 DW h -1 appeared in the flourishing period of leaf, the intermediate of 0.205 4 L·kg -1 DW h -1 appeared in the senescent period, and the lowest of 0.165 1 L·kg -1 DW h -1 appeared in the defoliating period. The rank of transpiration rate under different weather condition was in the order of sunny day > changeable day > rainy day. Annually, the lowest transpiration rate of 0.043 6 L·kg -1 DW h -1 occurred in March and the zenith of 0.179 3 L·kg -1 DW h -1 appeared in June. Radiation and temperature had great influence on the transpiration rate of C. camphora.
The ICT\|2000TE meteorological measurement system was used to determine the transpiration rate of Cinnamomum camphora and the variation of main ecological factors around canopy layer.The results indicated that under full light condition in sunny days, a single peak curve was found in the daily variation of radiation and temperature around canopy layer. The radiation started to increase at 6:00 am and reached the peak of 150~800 μmol·m -2 s -1 at 12:00 , then declined to 0 at 18:00? ?0:00pm. The summer had the high variation and long time of radiation. Temperature reached the peak at 15:00—17:00. However, the daily change of humidity showed a reverse tendency in comparison with that of radiation and temperature. The humidity began to decrease at 6:00 and slumped to the lowest at 15:00 and then increased. The daily change of transpiration rate of C. camphora was found in the form of single peak curve and the highest value occurred at 14:00. The highest transpiration rate of 0.503 1 L·kg -1 DW h -1 appeared in the flourishing period of leaf, the intermediate of 0.205 4 L·kg -1 DW h -1 appeared in the senescent period, and the lowest of 0.165 1 L·kg -1 DW h -1 appeared in the defoliating period. The rank of transpiration rate under different weather condition was in the order of sunny day > changeable day > rainy day. Annually, the lowest transpiration rate of 0.043 6 L·kg -1 DW h -1 occurred in March and the zenith of 0.179 3 L·kg -1 DW h -1 appeared in June. Radiation and temperature had great influence on the transpiration rate of C. camphora.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2004年第2期170-173,共4页
Scientia Silvae Sinicae
基金
国家自然科学基金重大项目 ( 3 98993 70 )
国家重点野外台站资助项目 ( [2 0 0 0 ]国科基便字第 0 76号 )
国家林业局重点科研项目( 2 0 0 1-7)
湖南省自然科学基金 ( 0 0JJY2 0 2 4)
中南林学院青年基金项目 ( 2 743 )的部分内容
关键词
樟树
林冠层
生态因子
蒸腾速率
Cinnamomum camphora , Transpiration rate, Around canopy layer, Ecological factors