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Correlations of stomatal conductance with hydraulic and chemical factors in several deciduous tree species in a natural habitat
Author(s) -
AUGÉ ROBERT M.,
GREEN CRAIG D.,
STODOLA ANN J. W.,
SAXTON ARNOLD M.,
OLINICK JOSHUA B.,
EVANS RICHARD M.
Publication year - 2000
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.1469-8137.2000.00604.x
Subject(s) - xylem , stomatal conductance , deciduous , vapour pressure deficit , temperate climate , botany , biology , temperate deciduous forest , ecophysiology , environmental science , ecology , photosynthesis , transpiration
Recent research in whole‐plant stomatal physiology, conducted largely with potted plants in controlled environments, suggests that stomatal conductance ( g s ) might be more closely linked to plant chemical variables than to hydraulic variables. To test this in a field situation, seasonal g s was examined in relation to a number of plant and environmental variables in 11 temperate, deciduous forest tree species. Stomatal conductance was generally better correlated with environmental variables (air temperature, vapor pressure deficit, PPFD) than with plant variables, and slightly better correlated with plant hydraulic variables (shoot water and osmotic potentials) than with plant chemical variables (xylem sap ABA concentration, xylem sap pH). We examined a model, developed previously for maize, which describes regulation of g s by xylem sap ABA concentration with leaf water status acting to modify stomatal sensitivity to the ABA signal. This model explained slightly more variation in seasonal g s in the forest trees than did single plant variables but not more variation than most single environmental variables. Response surface models, especially those incorporating environmental variables, were more consistently successful at explaining g s across species.