Variation in nocturnal stomatal conductance and development of predawn disequilibrium between soil and leaf water potentials in nine temperate deciduous tree species

2021 ◽  
Author(s):  
Ott Kangur ◽  
Kathy Steppe ◽  
Jeroen D. M. Schreel ◽  
Jonas S. von der Crone ◽  
Arne Sellin
Keyword(s):  
Stomatal Conductance ◽  
Tree Species ◽  
Leaf Water ◽  
Deciduous Tree ◽  
Water Potentials ◽  
Temperate Deciduous

Light sensitivity of shoot hydraulic conductance in five temperate deciduous tree species

2012 ◽  
Vol 39 (8) ◽  
pp. 661 ◽  
Author(s):  
Krõõt Aasamaa ◽  
Anu Sõber
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Water Use ◽  
Tree Species ◽  
Light Sensitivity ◽  
Hydraulic Conductance ◽  
Leaf Water ◽  
Deciduous Tree ◽  
Temperate Deciduous ◽  
Shoot Hydraulic Conductance

The light sensitivity of the shoot hydraulic conductance in five temperate deciduous tree species was measured using two methods to clarify the role of light sensitivity and the suitability of the methods used to study it. The light sensitivity measured using a method that included an interruption of ≤10 min in shoot light acclimation did not differ from that measured using a method with continuous illumination. The ‘noncontinuous light’ methods are suitable for measuring hydraulic conductance and its light response. Light sensitivity correlated with other leaf water traits as follows: positively with the ion-mediated increase in xylem hydraulic conductance; a relative decrease in the hydraulic conductance of the laminae in response to HgCl2; a relative change in stomatal conductance in response to changes in PAR intensity or atmospheric CO2 concentration, or to a decrease in air humidity or leaf water potential; and with instantaneous water use efficiency. The traits correlated negatively with shoot hydraulic conductance, stomatal conductance and relative increases in stomatal conductance in response to increases in leaf water potential. We suggest that high light sensitivity should be considered as one of the characteristics of conservative water use in trees. Low blue light increased shoot hydraulic conductance to a similar extent to moderate white light and twice as much as moderate red light. Blue light perception is important in the light sensitivity mechanism.

Seasonal patterns of xylem sap pH, xylem abscisic acid concentration, leaf water potential and stomatal conductance of six evergreen and deciduous Australian savanna tree species

2002 ◽  
Vol 50 (2) ◽  
pp. 229 ◽  
Author(s):  
Dane S. Thomas ◽  
Derek Eamus
Keyword(s):  
Abscisic Acid ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Tree Species ◽  
Xylem Sap ◽  
Leaf Water ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Water Potentials

Deciduous trees of Australia’s northern savannas typically have less-negative leaf water potentials than evergreen species and their stomata are more sensitive to soil drought than those of evergreen species. This paper presents the first investigation of the role of xylem sap pH and abscisic acid content in explaining stomatal behaviour of Australian trees in the field. We measured stomatal conductance, leaf-to-air vapour pressure difference (D) and leaf water potential, xylem abscisic acid (ABA) concentration and xylem sap pH of evergreen, semideciduous and fully deciduous tree species in the field over a 15-month period. Measurements were made during both the wet and the dry seasons. Stomata closed in response to increasing D in both evergreen and deciduous species and were equally sensitive to increasing D or declining leaf water potential. Xylem ABA concentration increased with declining leaf water potential in evergreen and semi-deciduous species, but not deciduous species. Similarly, there was an inverse correlation between stomatal conductance and xylem ABA concentration. Xylem sap pH increased as leaf water potential declined from wet to dry season for evergreen and semi-deciduous species but not for deciduous species. Deciduous species had less-negative water potentials and lower xylem ABA concentrations than evergreen species or semi-deciduous species. We conclude that changes in xylem sap pH and ABA content do occur seasonally in the wet–dry tropics of Australia and that these changes influence stomatal conductance, but only in evergreen and semi-deciduous species. Deciduous species do not appear to modulate either of these chemical signals.

scholarly journals Warming increases the sensitivity of seedling growth capacity to rainfall in six temperate deciduous tree species

AoB Plants ◽  
2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Vikki L Rodgers ◽  
Nicholas G Smith ◽  
Susanne S Hoeppner ◽  
Jeffrey S Dukes
Keyword(s):  
Seedling Growth ◽  
Tree Species ◽  
Deciduous Tree ◽  
Growth Capacity ◽  
Temperate Deciduous

Effect of Water Stress on Stomatal Conductance and Leaf Water Relations of Leaves Along Current-Year Branches of Peach

1989 ◽  
Vol 16 (6) ◽  
pp. 549 ◽  
Author(s):  
SL Steinberg ◽  
MJ Mcfarland ◽  
JC Miller
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Water Status ◽  
Stomatal Closure ◽  
Water Flux ◽  
Leaf Water ◽  
Leaf Water Status ◽  
Mature Leaves ◽  
Water Potentials

A gradation, that reflects the maturity of the leaves, exists in the leaf water, osmotic and turgor potential and stomatal conductance of leaves along current and 1-year-old branches of peach. Predawn leaf water potentials of immature folded leaves were approximately 0.24 MPa lower than mature leaves under both well-watered and dry conditions. During the daytime the leaf water potential of immature leaves reflected the water potential produced by water flux for transpiration. In well- watered trees, mature and immature unfolded leaves had a solute potential at least 0.5 MPa lower than immature folded leaves, resulting in a turgor potential that was approximately 0.8 MPa higher. The turgor requirement for growth appeared to be much less than that maintained in mature leaves. As water stress developed and leaf water potentials decreased, the osmotic potential of immature folded leaves declined to the level found in mature leaves, thus maintaining turgor. In contrast, mature leaves showed little evidence of turgor maintenance. Stomatal conductance was lower in immature leaves than in fully mature leaves. With the onset of water stress, conductance of mature leaves declined to a level near that of immature leaves. Loss of turgor in mature leaves may be a major factor in early stomatal closure. It was concluded that osmotic adjustment played a role in maintenance of a leaf water status favorable for some growth in water-stressed immature peach leaves.

Stomatal and photosynthetic response of drought-stressed cherrybark oak (Quercusfalcata var. pagodaefolia) and sweet gum (Liquidambarstyraciflua)

1986 ◽  
Vol 16 (4) ◽  
pp. 841-846 ◽  
Author(s):  
S. R. Pezeshki ◽  
J. L. Chambers
Keyword(s):  
Stomatal Conductance ◽  
Stomatal Closure ◽  
Net Photosynthesis ◽  
Leaf Water ◽  
Dominant Factor ◽  
Controlled Environment ◽  
Photosynthetic Response ◽  
Stomatal Limitation ◽  
Water Potentials ◽  
Relative Decline

The effects of water stress on stomatal conductance and net photosynthesis of cherrybark oak (Quercusfalcata var. pagodaefolia Ell.) and sweet gum (Liquidamberstyraciflua L.) seedlings were studied under controlled environment conditions during the 1983 growing season. Drought stress induced stomatal closure and significant declines in net photosynthesis for both species. Stomatal conductance declined by as much as 43% in cherrybark oak and 82% in sweet gum compared with predrought levels. Net photosynthetic rates also declined 85% from predrought levels in sweet gum and fell below zero in cherrybark oak. The remarkable decline in net photosynthesis in cherrybark oak while stomata remained partially open suggests that in addition to a stomatal effect, nonstomatal factors were involved in the reduction of net photosynthesis. In sweet gum, however, stomatal limitation of net photosynthesis seems to be the dominant factor. The greater relative decline in mean leaf conductance in sweet gum suggests a greater reaction to drought by this species through effective and rapid stomatal closure resulting in avoidance of leaf desiccation. Stomata of cherrybark oak, on the other hand, were less sensitive to low leaf water potentials; therefore, stomatal closure occurred at significantly lower (more negative) leaf water potentials when compared with sweet gum.

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