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Non‐stomatal limitation of CO 2 assimilation in three tree species during natural drought conditions
Author(s) -
Briggs G. M.,
Jurik T. W.,
Gates D. M.
Publication year - 1986
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1986.tb05961.x
Subject(s) - assimilation (phonology) , stomatal conductance , hardwood , carbon assimilation , photosynthesis , botany , chemistry , horticulture , biology , philosophy , linguistics
The effect of drought on CO 2 assimilation and leaf conductance was studied in three northern hardwood species: Quercus rubra L., Acer rubrum L. and Populus grandidentata Michx. Leaf gas exchange characteristics at two CO 2 levels (320 and 620 μl I −1 ) and temperatures from 20 to 35°C were measured at the end of a dry period and shortly after 10 cm of rainfall. The effects of drought varied with species, temperature and CO 2 level. Calculated values of internal CO 2 concentration showed little or no decline during drought. Differences in assimilation, before vs after the rains, were most apparent at the higher CO 2 level. These latter two observations indicate nonstomatal disruption of CO 2 assimilation during the dry period. In P. grandidentata there was a substantial interaction between drought and temperature, with a resultant shift in the temperature for maximum assimilation to lower temperatures during drought. During drought, internal CO 2 concentrations increased sharply in all three species under the combined conditions of high temperatures and the higher CO 2 level.