Internal and external control of net photosynthesis and stomatal conductance of mature eastern white pine (Pinusstrobus)

1992 ◽  
Vol 22 (9) ◽  
pp. 1387-1394 ◽  
Author(s):  
C.A. Maier ◽  
R.O. Teskey
Keyword(s):  
Internal Control ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Leaf Conductance ◽  
External Control ◽  
White Pine ◽  
Eastern White Pine ◽  
Pressure Potential ◽  
Growing Seasons ◽  
Xylem Pressure Potential

Leaf gas exchange and water relations were monitored in the upper canopy of two 25 m tall eastern white pine (Pinusstrobus L.) trees over two consecutive growing seasons (1986 and 1987). Examination of the seasonal and diurnal patterns of net photosynthesis and leaf conductance showed that both internal and external (environmental) factors were controlling net photosynthesis and leaf conductance. Internal control was indicated by a rapid increase and then decrease in the photosynthetic capacity of 1-year-old foliage during the development and maturation of current-year foliage, which was independent of environmental conditions. Large differences in net photosynthesis were observed between growing seasons due to seasonal differences in soil water availability, as indexed by predawn xylem pressure potential. Water stress reduced the maximum rate of net photosynthesis and altered the response of net photosynthesis and leaf conductance to absolute humidity deficit.

Comparison of Water Relations and Osmotic Adjustment in Sorghum and Cowpea Under Field Conditions

1983 ◽  
Vol 10 (5) ◽  
pp. 423 ◽  
Author(s):  
KA Shackel ◽  
AE Hall
Keyword(s):  
Soil Water ◽  
Osmotic Adjustment ◽  
Leaf Conductance ◽  
Field Conditions ◽  
Soil Water Depletion ◽  
Pressure Potential ◽  
Water Depletion ◽  
Diurnal Patterns ◽  
Diurnal Range ◽  
Xylem Pressure Potential

Seasonal and diurnal patterns of xylem pressure potential, Ψx, and osmotic potential, Ψs, were compared using contrasting genotypes of sorghum [Sorghum bicolor (L.) Moench] and cowpea [Vigna unguiculata (L.) Walp.] under frequently imgated 'wet' and water-limited 'dry' field conditions. Generally, differences in Ψx and Ψs among genotypes within each species were small compared with differences between the two species. Sorghum exhibited a larger diurnal range and larger differences between wet and dry treatments for Ψx, Ψs, and estimates of bulk leaf turgor than did cowpea. Seasonal and drought- induced osmotic adjustment occurred in sorghum, but not in cowpea. Diurnal patterns of leaf conductance indicated that, under the dry treatment, cowpea avoided the occurrence of large plant water deficits by substantial reductions in leaf conductance, especially at midday, whereas sorghum maintained moderate values of leaf conductance throughout the day. Cowpea exhibited a larger diurnal range of leaf conductance and larger differences between wet and dry treatments than did sorghum. Differences were not observed between the species in overall soil water depletion or in root activity as estimated from profiles of soil water depletion until senescence occurred in cowpea. Sorghum genotypes that had been selected on the basis of differences in Ψs did exhibit significant differences in average values of leaf conductance and total soil water depletion, but the genotype that had the lowest Ψs (M35-1) also had the lowest leaf conductance and the least soil water depletion.

Winter Leaf Conductance Rates of Pinus Strobus L. (Eastern White Pine)

2008 ◽  
Vol 29 (5) ◽  
pp. 474-482
Author(s):  
Delphis F. Levia ◽  
Lydia A. Leclair
Keyword(s):  
Pinus Strobus ◽  
Leaf Conductance ◽  
White Pine ◽  
Eastern White Pine

Water relations of loblolly pine trees in southeastern Oklahoma following precommercial thinning

1990 ◽  
Vol 20 (9) ◽  
pp. 1508-1513 ◽  
Author(s):  
Bert M. Cregg ◽  
Thomas C. Hennessey ◽  
Philip M. Dougherty
Keyword(s):  
Water Potential ◽  
Water Relations ◽  
Loblolly Pine ◽  
Soil Water Potential ◽  
Basal Area ◽  
Leaf Conductance ◽  
Pressure Potential ◽  
Precommercial Thinning ◽  
Xylem Pressure ◽  
Xylem Pressure Potential

Xylem pressure potential, leaf conductance, transpiration, and soil moisture were measured during three summers following precommercial thinning of a 10-year-old stand of loblolly pine (Pinustaeda L.) in southeastern Oklahoma. The stand was thinned to three target basal-area levels: 5.8, 11.5, and 23 m2•ha−1 (control). Soil water potential increased significantly in response to thinning during the summer of each year studied. However, plant water relations were relatively unaffected by the treatments. Significant thinning effects on diurnal xylem pressure potential were observed on only 7 of 55 measurement periods. Treatment differences in conductance and transpiration observed during the first year of the study appeared to be related to differences in light interception and crown exposure. Regression analysis indicated response of leaf conductance and transpiration to predawn xylem pressure potential and vapor pressure deficit was not affected by the thinning treatments. Overall, the results of this study are consistent with a hypothesis in which transpiration, leaf area, and water potential interact to form a homeostatic relationship.

scholarly journals Budset and Growth of Eastern White Pine Following Application of 6-Benzylaminopurine to Seedlings Fertilized with Different Levels of Nitrogen

1988 ◽  
Vol 6 (2) ◽  
pp. 42-45
Author(s):  
L. Eric Hinesley ◽  
Robert D. Wright
Keyword(s):  
Irrigation Water ◽  
Pinus Strobus ◽  
Dry Weight ◽  
Growing Season ◽  
First Year ◽  
White Pine ◽  
Eastern White Pine ◽  
Growing Seasons ◽  
One Year ◽  
Different Levels

Eastern white pine (Pinus strobus L.) were potted and solution fed once weekly during 2 growing seasons with 5 levels of N in the irrigation water: 50, 100, 200, 300 and 400 ppm. Leaders were treated with 750 ppm 6-benzylaminopurine (BA) in late June of the first year. The higher N levels resulted in greater stem diameter, greater foliage dry weight, longer and heavier needle fascicles, better foliage color, greater budset after application of BA, and more and longer branches on the BA-treated leader the second growing season. BA should be applied to trees with N concentration ≥ 1.5% in one-year-old foliage.

Pathogen-induced defoliation impacts on transpiration, leaf gas exchange, and non-structural carbohydrate allocation in eastern white pine (Pinus strobus)

Trees ◽  
2020 ◽  
Author(s):  
Cameron D. McIntire ◽  
Brett A. Huggett ◽  
Emma Dunn ◽  
Isabel A. Munck ◽  
Matthew A. Vadeboncoeur ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Pinus Strobus ◽  
White Pine ◽  
Eastern White Pine ◽  
Structural Carbohydrate

scholarly journals Growth of Eastern White Pine (Pinus strobus L.) Related to Forest Floor Consumption by Prescribed Fire in the Southern Appalachians

2002 ◽  
Vol 26 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Katherine J. Elliott ◽  
James M. Vose ◽  
Barton D. Clinton
Keyword(s):  
Forest Floor ◽  
Fire Severity ◽  
The Other ◽  
Size Difference ◽  
Southern Appalachians ◽  
White Pine ◽  
Eastern White Pine ◽  
Growing Seasons ◽  
Humus Layer

Abstract Chainsaw felling, burning, and planting of eastern white pine (Pinus strobusL.) have been prescribed on degraded pine/hardwood stands in the Southern Appalachians to improve overstory composition and productivity. The desired future condition of the overstory is a productive pine/hardwood mixture, with white pine, which is resistant to southern pine beetle (Dendroctonus frontalis), as the dominant pine. We evaluated the growth of white pine planted after fell-and-burn treatments through eight growing seasons after planting on three sites that differed in their fire characteristics and carbon and nitrogen losses. The three sites (JE, JW, and DD) differed in heat penetration and forest floor consumption. Although very little consumption of the Oe+Oa humus layer occurred during burning, consumption of the Oi litter layer was 94%, 94%, and 63% at JE, JW, and DD, respectively. Corresponding to the forest floor layer consumption (Oi and Oe+Oa combined), 46% of forest floor N was lost at JE, 45% of forest floor N was lost at JW, and less than 0.1% of the forest floor N was lost at DD. Biomass and density of woody competitor species were not significantly related to white pine size or growth. By the eighth growing season, no differences in white pine size or growth were detected between JE and JW, but DD had significantly smaller white pine trees. The size difference between DD and the other two sites was attributed to the replanting of seedlings at DD in 1992. However, relative growth rate (RGR) was significantly higher on DD in 1998 than the other two sites. Eight growing seasons after planting, white pine growth was negatively related to percent Oi layer consumed on the JE and JW sites. We also found significant relationships between white pine RGR and percent Oi consumed using data from all three sites. Although fire severity had a long-term effect on pine growth, fire severity was considered low overall on these sites because there were limited losses from the forest floor Oe+Oa layer. However, white pine increment and RGR were significantly related to percent forest floor Oi mass and N loss. This loss of site N capital could have a significant negative effect on growth of planted white pine over the long term. South. J. Appl. For. 26(1):18–25.

Seed pre-treatment using a derivative of 5-hydroxybenzimidazole (AMBIOL) pre-acclimates carrot seedlings to drought

2002 ◽  
Vol 82 (1) ◽  
pp. 195-202 ◽  
Author(s):  
Lada R. Rajasekaran ◽  
Terence J. Blake
Keyword(s):  
Root Growth ◽  
Dry Matter ◽  
Net Photosynthesis ◽  
Membrane Capacitance ◽  
Dry Matter Production ◽  
Pressure Potential ◽  
Drought Acclimation ◽  
Matter Production ◽  
Xylem Pressure Potential ◽  
Pre Treatment

The possibility that AMBIOL, a derivative of 5-hydroxybenzimidazole, may promote drought acclimation of carrot seedlings was studied. Carrot seeds were pre-treated by soaking in AMBIOL solutions of 0, 0.1, 1 or 10 mg L–1 for 24 h and germinated. Fifteen-day-old seedlings were exposed to a 7-d drought by withholding water until soil moisture content declined to one-third of the initial values. Drought caused a significant reduction in xylem pressure potential, elongation growth, leaf area expansion, root growth and dry matter production. Membrane capacitance, net photosynthesis, stomatal conductance, transpiration and water use efficiency all declined in all plants under drought. However, seed pre-treatment using AMBIOL 0.1 and 10 mg L–1 completely alleviated the drought-induced reduction in shoot dry matter production. Seed preconditioning using AMBIOL 10 mg L–1 promoted dry matter production, which was 214% higher than in the untreated droughted plants and was even 26% higher than that of the untreated, unstressed controls. AMBIOL appeared to have induced drought acclimation through root adjustments that enhanced root growth, possibly supplying root-derived essential factors. Key words: Acclimation, antioxidant, carrot, drought, dry matter production, 5-hydroxybenzimidazole, growth, membrane capacitance

scholarly journals Stomatal and non-stomatal limitations to photosynthesis of Populus euphratica Oliv. leaves in an extremely arid area of northwestern China

2019 ◽  
Author(s):  
Guanlong Gao ◽  
Qi Feng ◽  
Xiande Liu
Keyword(s):  
Leaf Gas Exchange ◽  
Populus Euphratica ◽  
Net Photosynthesis ◽  
Distribution Patterns ◽  
Northwestern China ◽  
Stomatal Limitation ◽  
Natural Conditions ◽  
Growing Seasons ◽  
Populus Euphratica Oliv ◽  
Stomatal Limitations

Abstract On the basis of successive measurements of leaf gas exchange during the main growing seasons of Populus euphratica Oliv. in 2013 and 2014, respectively, we analyzed the stomatal and non-stomatal limitations to photosynthesis under natural conditions in an extremely arid region of northwestern China. Our results showed that (1) the distribution patterns of net photosynthesis (Pn) and stomatal conductance (gs) were similar, both of which increased in the morning, peaked at around noon, and then decreased. This contrasted with the observed changes in sub-stomatal CO2 concentrations (Ci). (2) The phenomenon of midday depression of photosynthesis (MDP) was obvious from July to September during the two years. At the beginning of MDP, the stomatal limitation to photosynthesis (Ls) peaked, where its predominance was supported by Ci being at a minimum. Thereafter, Ls decreased and Ci/gs increased sharply, indicating that the non-stomatal limitation to photosynthesis predominated. (3) Both the Ls and relative stomatal limitation to photosynthesis (RLs) increased in the morning, and then decreased, whereas Ci/gs presented contrary changes. (4) The RLs values were greater than the Ls values, which was mainly due to the nonlinearity of the Pn/Ci curve, which often leads to large overestimations. (5) The Ls values in our study were much greater than those from other studies under natural conditions. The most probable reason was that the extremely high temperature and scarce water resource caused the stomata to close to reduce transpiration, resulting in the stomatal limitation to photosynthesis being more intense.

Growth and ecophysiological responses of black spruce seedlings to elevated CO2 under varied water and nutrient additions

1993 ◽  
Vol 23 (6) ◽  
pp. 1033-1042 ◽  
Author(s):  
Kurt H. Johnsen
Keyword(s):  
Gas Exchange ◽  
Black Spruce ◽  
Seedling Emergence ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Pressure Potential ◽  
Foliar N ◽  
Nutrient Additions ◽  
Xylem Pressure Potential ◽  
Ecophysiological Responses

Two controlled-environment studies examined growth and ecophysiological responses of black spruce (Piceamariana (Mill.) B.S.P.) seedlings to elevated CO2 under varied water and nutrient additions. Growth analyses were conducted followed by measurements of gas exchange, xylem pressure potential and foliar N concentrations. Growth under elevated CO2 (700 ppm) increased final seedling dry weights by 20–48% compared with seedling growth under ambient CO2 (350 ppm). Percent increases in seedling dry weight were greater under drought versus well-watered conditions and higher versus lower nutrient additions. Seedlings grown under elevated CO2 displayed higher water use efficiency than seedlings grown under ambient CO2. This was apparent based upon instantaneous gas exchange as well as xylem potential pressure measurements. Elevated CO2-induced stimulation of relative growth rate was greatest shortly after seedling emergence and decreased with increased seedling size. Acclimation of net photosynthesis was observed and was reversible. Analyses using allometric principles indicate net photosynthetic acclimation resulted from: (i) growth-induced nutrient dilution; (ii) a decrease in foliar N levels not owing to dilution; and (iii) a decrease in net photosynthetic activity.

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