Stomatal and photosynthetic response of sweet gum (Liquidambarstyraciflua) to flooding

1985 ◽  
Vol 15 (2) ◽  
pp. 371-375 ◽  
Author(s):  
S. R. Pezeshki ◽  
J. L. Chambers
Keyword(s):  
Stomatal Conductance ◽  
Water Status ◽  
Stomatal Closure ◽  
Net Photosynthesis ◽  
Controlled Environment ◽  
Photosynthetic Response ◽  
Short Term ◽  
Pressure Potential ◽  
Xylem Pressure ◽  
Xylem Pressure Potential

Effects of short-term flooding on stomatal conductance, net photosynthesis, and water status of sweet gum (Liquidambarstyraciflua L.) seedlings were studied under controlled environment conditions. Flooding for 9 days induced partial stomatal closure, resulting in significant declines in transpiration and net photosynthesis. The response to flooding was rapid with an average daily stomatal conductance declining from a preflood level of 0.43 cm•s−1 to 0.26 cm•s−1 by 24 h after flooding began (40% reduction). The average preflooding daily net photosynthesis was reduced from 13.7 to 10.2 mg CO2•dm−2•h−1 (25% reduction) during the same period and the average daily stomatal conductance and net photosynthesis for the 9th day of flooding were reduced by 70 and 77%, respectively, compared with preflood levels. The leaf xylem pressure potential measurements, however, indicated that water deficits did not develop as a result of flooding. Partial stomatal reopening 3 days after termination of flooding was noted with an average daily stomatal conductance approaching 63% of the preflood levels and an average daily net photosynthesis reaching 46% of its preflood levels. Maintenance of positive net photosynthesis throughout flooding, and partial stomatal and photosynthetic recovery following drainage may account for the tolerance of sweet gum seedlings to short-term flooding.

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.

Stomatal control and the development of water deficit in Engelmann spruce seedlings during drought

1979 ◽  
Vol 9 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Merrill R. Kaufmann
Keyword(s):  
Flux Density ◽  
Stomatal Closure ◽  
Absolute Humidity ◽  
Pressure Potential ◽  
Evaporative Demand ◽  
Xylem Pressure ◽  
Full Sunlight ◽  
Engelmann Spruce ◽  
Xylem Pressure Potential ◽  
The Relationship

The effects of soil drying on water relations of Engelmann spruce (Piceaengelmannii Engelm.) were studied by withholding water from 4-year-old potted seedlings in full sunlight and under a shade screen transmitting 55–60% light. During a period of 2 months, xylem pressure potential, water vapor conductance, and transpirational flux density gradually declined compared with well watered controls, with drying being more rapid in full sunlight. As drying progressed, xylem pressure potential at 0 transpiration (predawn potential) decreased and the slope of the relationship between xylem pressure potential and transpirational flux density became more negative. Hysteresis in the relationship occurred when predawn xylem pressure potential was −6 bars (1 bar = 105 Pa) or lower. Needle conductance during daylight hours decreased as the absolute humidity difference from leaf to air increased but conductances were lower in September than in August for given humidity differences. Xylem pressure potentials between −15 and −19 bars had no clear effect on conductance in August but apparently caused significant stomatal closure in September. Because of humidity-induced stomatal closure, evaporative demand had little effect on transpirational flux density over a broad range of humidity gradient. Thus increased leaf-to-air vapor gradients for transpiration are not always accompanied by increased transpiration.

Drought-induced leaf abscission and whole-plant drought tolerance of seedlings of seven black walnut families

1985 ◽  
Vol 15 (5) ◽  
pp. 818-821 ◽  
Author(s):  
William C. Parker ◽  
Stephen G. Pallardy
Keyword(s):  
Drought Tolerance ◽  
Water Status ◽  
Black Walnut ◽  
Leaf Abscission ◽  
Pressure Potential ◽  
Xylem Pressure ◽  
Whole Plant ◽  
Geographic Origins ◽  
Xylem Pressure Potential ◽  
Different Levels

Whole-plant drought tolerance and leaf abscission in response to drought of 5-month-old, half-sib black walnut (Juglansnigra L.) seedlings representing seven geographic origins were examined. Seedlings were subjected to six different levels of drought stress and then reirrigated. Mortality, leaf abscission, and refoliation responses were measured. Only one of 404 seedlings actually died. Survival of stem cambial tissues at predawn leaf xylem pressure potential values as low as −4.0 MPa was associated with the capacity for drought-induced leaf abscission. The percentage of seedlings exhibiting at least 80% leaf abscission increased linearly as predawn leaf xylem pressure potential decreased from −1.5 to −3.5 MPa. Although substantial differences in leaf abscission among families were observed, these differences were not statistically significant (P ≤ 0.05). Eighteen percent of all seedlings exhibited some degree of refoliation upon recovery of plant water status. However, the cumulative area of regrowth foliage was insignificant in terms of its adaptive value for resumption of photosynthetic activity following stress relief.

Changes in xylem pressure potential of red spruce seedlings treated with ozone and simulated acid rain

1989 ◽  
Vol 19 (9) ◽  
pp. 1200-1203 ◽  
Author(s):  
Bruce R. Roberts ◽  
William N. Cannon Jr.
Keyword(s):  
Acid Rain ◽  
Stomatal Closure ◽  
Turgor Pressure ◽  
Red Spruce ◽  
Pressure Potential ◽  
Xylem Pressure ◽  
Xylem Pressure Potential ◽  
Acid Rainfall ◽  
Area Expansion ◽  
Air Control

Two-year-old containerized seedlings of red spruce (Picearubens Sarg.) were exposed for 8 weeks to charcoal-filtered air (control) or to 7 and 15 parts per hundred million (pphm) ozone (O3) alone and 15 pphm O3 in combination with simulated acid rainfall at pH 4.2 and 3.0 prior to measuring shoot xylem pressure potential. Pressure potential determinations for seedlings treated with O3 alone or O3 + acid rain were always higher (less negative) than similar determinations made on comparable seedlings grown in charcoal-filtered air. These results suggest that exposure to atmospheric deposition may affect xylem pressure potential indirectly by influencing transpirational water loss via stomatal closure and (or) reductions in leaf area expansion. Calculations of osmotic potential and turgor pressure suggest the possibility of some osmotic adjustment in response to deposition stress in this species.

Pressure Chamber and Air Flow Porometer for Rapid Field Indication of Water Status and Stomatal Condition in Wheat

1977 ◽  
Vol 13 (4) ◽  
pp. 341-351 ◽  
Author(s):  
R. A. Fischer ◽  
M. Sanchez ◽  
J.R. Syme
Keyword(s):  
Field Experiments ◽  
Water Status ◽  
Air Flow ◽  
Pressure Chamber ◽  
Plant Responses ◽  
Pressure Potential ◽  
Xylem Pressure ◽  
Xylem Pressure Potential ◽  
Plant Water Potential ◽  
Key Features

SUMMARYPlant water potential and leaf diffusive conductance, key features of plant responses to water stress in field experiments, can be estimated, respectively, by xylem pressure potential measured with the pressure chamber apparatus, and leaf permeability measured with the air flow porometer. This paper describes modifications to these two techniques in order to increase the rapidity of measurements in wheat to 60/h with the pressure chamber, and 200/h with the porometer. Rapid measurements are needed because of the large within-and between-plot errors encountered with daytime measurements in typical field experiments, examples of which are presented.

The water status of six woody species coexisting in the Sahel (Ferlo, Senegal)

1996 ◽  
Vol 12 (5) ◽  
pp. 607-627 ◽  
Author(s):  
A. Berger ◽  
M. Grouzis ◽  
C. Fournier
Keyword(s):  
Anthropogenic Disturbance ◽  
Water Status ◽  
Woody Species ◽  
Dry Season ◽  
Pressure Potential ◽  
Balanites Aegyptiaca ◽  
Xylem Pressure ◽  
Xylem Pressure Potential ◽  
Boscia Senegalensis ◽  
Coexisting Species

ABSTRACTIn the Sahel during recent decades, anthropogenic disturbance and periods of drought have caused changes in woody species frequency. The internal water status of six coexisting species was analysed to estimate the importance of water constraints in this process. Predawn and midday xylem pressure potential and stomatal conductance were monitored monthly for two years. The relations between xylem pressure potential and transpiration made it possible to determine the hydraulic conductivity of the soil—plant system. Two types of results were obtained. First, there was considerable diversity in water status of the different species. Minimum predawn xylem pressure potentials (dry season) ranged from – 1.5 MPa to – 5 MPa depending on species, with interseasonal variation from 0.08 MPa to 2 MPa. Response to rainfall was very rapid (a few days) or very slow (several months). The three functioning types defined using these results were compared with the phytogeographical status of the species. Second, more specific phenomena were observed, (a) Some species (Balanites aegyptiaca and Boscia senegalensis) showed an imbalance between the predawn xylem pressure potential and the soil water status during the rainy season; (b) a sharp increase in xylem pressure potential was observed in deciduous species in the middle of the dry season; probably related to bud break; and (c) the water status was always favourable for Combrelum glutinosum. The few remaining individuals seem to benefit from very favourable subsoil water supply conditions.

Relation between root system size and water inflow capacity of Abiesamabilis growing in a subalpine forest

1985 ◽  
Vol 15 (4) ◽  
pp. 669-672 ◽  
Author(s):  
Robert O. Teskey ◽  
Charles C. Grier ◽  
Thomas M. Hinckley
Keyword(s):  
Root System ◽  
Stomatal Closure ◽  
System Size ◽  
Water Inflow ◽  
Subalpine Forest ◽  
Silver Fir ◽  
Small Contribution ◽  
Pressure Potential ◽  
Xylem Pressure ◽  
Xylem Pressure Potential

The water inflow capacity of the root systems of several 15- to 18-year-old Pacific silver fir (Abiesamabilis (Dougl.) Forbes) trees was investigated under field conditions. Severance of as much as one-third of the roots had no effect on xylem pressure potential, leaf conductance, or transpiration throughout the day following this treatment. Severance of more than half of the root system caused a decline in xylem pressure potential and partial stomatal closure. Measurements from trees which had been completely severed from their roots indicated that stored water made only a small contribution to the supply of water to the foliage of these trees. It was concluded that a balance did not exist between the capacity for water inflow and the rate of foliar water loss, at least in periods without drought. One advantage of excess absorptive capacity may be the ability to obtain adequate amounts of water from relatively small portions of the rooting zone.

Stomatal conductance patterns and environment in high elevation phreatophytes of Wyoming

1991 ◽  
Vol 69 (3) ◽  
pp. 647-655 ◽  
Author(s):  
Jeffrey R. Foster ◽  
William K. Smith
Keyword(s):  
Stomatal Conductance ◽  
Stomatal Closure ◽  
Soil Water Potential ◽  
High Elevation ◽  
Pressure Potential ◽  
Previous Night ◽  
Threshold Response ◽  
Populus Angustifolia ◽  
Xylem Pressure Potential ◽  
Air Vapor Pressure Deficit

High-elevation (2305 m) phreatophytes (cottonwood, Populus angustifolia James, and willows, Salix monticola Nutt. and Salix exigua Bebb) in southeastern Wyoming commonly showed a pattern of increasing stomatal conductance (g1) throughout the day, despite minimum leaf water potentials (ψ1) as low as −2.7 MPa. Diurnally, light and leaf temperature were the most important variables influencing g1, but there were also threshold values of ψ1 and leaf-to-air vapor pressure deficit for stomatal closure. Seasonally, maximum daily g1 (gmax) was similar between species, was positively related to minimum air temperature the previous night, and showed a threshold response to soil temperature. Two types of evidence existed for large soil-to-leaf conductances (gs–l) and for liquid water being available to the roots. The first was no change in ψ1 despite increasing transpiration during the afternoon. The second was rapid evening recovery of ψ1 often to values higher than mean soil water potential to 60-cm depth. The combination of low atmospheric pressures at high elevation, large gs–l, and access to a water table may explain how these phreatophytes attained gmax of 0.8–0.9 mol m−2 s−1, much higher than gmax of low-elevation phreatophytes or high-elevation nonphreatophytes. Key words: Populus, Salix, phreatophyte, stomatal conductance, xylem pressure potential.

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