CHANGES IN RATES OF PHOTOSYNTHESIS AND RESPIRATION DURING NEEDLE DEVELOPMENT OF LOBLOLLY-PINE

Citation
K. Radoglou et Ro. Teskey, CHANGES IN RATES OF PHOTOSYNTHESIS AND RESPIRATION DURING NEEDLE DEVELOPMENT OF LOBLOLLY-PINE, Tree physiology, 17(7), 1997, pp. 485-488
Citations number
10
Categorie Soggetti
Ecology,Forestry,"Plant Sciences
Journal title
ISSN journal
0829318X
Volume
17
Issue
7
Year of publication
1997
Pages
485 - 488
Database
ISI
SICI code
0829-318X(1997)17:7<485:CIROPA>2.0.ZU;2-O
Abstract
Net photosynthetic rates of developing foliage and one-year-old foliag e of loblolly pine (Pinus taeda L.) were measured under field conditio ns. In the subsequent year, net photosynthesis and dark respiration ra tes of current-year and one-year-old foliage were measured under contr olled environmental conditions. Loblolly pine foliage grows slowly, re aching its final size 3.5 to 4 months after bud burst. Positive rates of net photosynthesis were recorded when the foliage was 13 and 18% of final length, in the controlled-environment and field study, respecti vely. However, because of high rates of dark respiration during the in itial growth period, a positive diurnal carbon balance did not occur u ntil foliage was about a third of final length (40 days after bud burs t). Two months after bud burst, when foliage was about 55% of final le ngth, its photosynthetic capacity exceeded that of one-year-old foliag e. The highest rates of net photosynthesis were achieved when foliage was more than 90% fully expanded.