Ozone effects on grafted mature and juvenile red spruce: photosynthesis, stomatal conductance, and chlorophyll concentration

1993 ◽  
Vol 23 (3) ◽  
pp. 450-456 ◽  
Author(s):  
Joanne Rebbeck ◽  
Keith F. Jensen ◽  
Michael S. Greenwood
Keyword(s):  
Stomatal Conductance ◽  
Surface Area ◽  
Chlorophyll A ◽  
Chlorophyll Concentration ◽  
Net Photosynthesis ◽  
Red Spruce ◽  
Total Chlorophyll ◽  
Specific Leaf Weight ◽  
Open Top Chambers ◽  
Species Response

Red spruce (Picearubens Sarg.) was grown as grafted mature and juvenile scions in open-top chambers and exposed to charcoal-filtered air, nonfiltered air, and nonfiltered air with ozone additions of either 75 or 150 ppb above ambient to determine if tissue age affects the species response to oxidant pollution as measured by photosynthesis, stomatal conductance, and chlorophyll concentration. After 18 weeks of exposure to ozone of concentrations as high as 170 ppb (nonfiltered air + 150 ppb ozone) in an 8-h period, net photosynthesis of grafted red spruce was reduced by ozone. Significant reductions were not observed until September 1988. Mature and juvenile scions grown in nonfiltered air + 150 ppb ozone showed 29 and 40% reductions, respectively, in mean seasonal net photosynthesis (mg CO2•g dry wt.−1•h−1) compared with those plants grown in nonfiltered air. Scion age had a significant effect on net photosynthesis and stomatal conductance. Net photosynthesis (mg CO2•g dry wt.−1•h−1) and stomatal conductance were 38 and 47% higher, respectively, in juvenile than in mature scions. Chlorophyll a and total chlorophyll concentration of juvenile scion needles were significantly reduced 19 and 24%, respectively, when grown in nonfiltered air + 150 ppb ozone compared with that grown in charcoal-filtered air (p < 0.01). Mature scions had significantly more chlorophyll a than juvenile scions in October 1988. Current-year needles collected from mature scions had significantly greater mass, length, one-sided projected surface area, width, and thickness than juvenile scions. Mature scions had significantly lower needle numbers per centimetre branch than did juvenile scions. No differences in specific leaf weight were observed. Mature scions had less ozone uptake than did juvenile scions.

Fumigating mature spruce branches with SO2: effects on net photosynthesis and stomatal conductance

1994 ◽  
Vol 24 (7) ◽  
pp. 1464-1471 ◽  
Author(s):  
Fan-Rui Meng ◽  
R.M. Cox ◽  
Paul A. Arp
Keyword(s):  
Stomatal Conductance ◽  
Regression Models ◽  
Late Summer ◽  
Net Photosynthesis ◽  
Leaf Temperature ◽  
Red Spruce ◽  
Direct Proportion ◽  
Active Radiation ◽  
Foliage Leaf ◽  
Leaf Yellowing

Branches on mature red spruce trees (Picearubens Sarg.) were fumigated with SO2 in late summer of 1990 and 1991. There were four SO2 treatment levels (0, 0.1, 0.2, and 0.4 ppm) and 12 fumigation chambers. Each treatment was replicated on three neighboring trees. Net photosynthesis and stomatal conductance of current-year foliage were determined with a Li-Cor photosynthesis system. Rates of foliar SO2 absorption were estimated using regression models, with leaf temperature, relative humidity, atmospheric CO2 concentrations, and photosynthetically active radiation as predictors. Fumigation effects became visible in terms of needle yellowing and browning after a few weeks of treatment. Effects on net photosynthesis and stomatal conductance were generally negative and in direct proportion with cumulative foliar SO2 absorption. It was found that, in shade-adapted foliage, visible symptoms were delayed, and stomatal conductance was slightly stimulated at low SO2 levels. In other foliage, leaf yellowing and browning occurred earlier, and stomatal conductance was depressed. Net photosynthesis was depressed at about the same rate regardless of branch position. Foliage subjected to high SO2 concentration treatments did not recover from SO2 damage 1 year after treatment: needles had fallen off the twigs, and needle and twig length of new foliage was reduced.

scholarly journals Retranslocation of nutrients in coffee leaves of cultivars Red Catuaí IAC 144 and IAC 125 RN

2021 ◽  
pp. 586-593
Author(s):  
Carlos Diego da Silva ◽  
Alian Cássio Pereira Cavalcante ◽  
Marcos Fabian Sanabria Franco ◽  
Pedro Ruben Viera Fariña ◽  
Guilherme Antônio Vieira de Andrade ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Chlorophyll A ◽  
Photosynthetic Rate ◽  
Total Chlorophyll ◽  
Phenological Stages ◽  
Alternative Method ◽  
Internal Conductance ◽  
Young Leaves ◽  
The Ideal

Knowledge of the retranslocation of nutrients in plants can help in the management of coffee fertilization, especially with regard to the ideal time and method of application and the need for installments. The aim of this study was to evaluate the retranslocation of nutrients in coffee leaves of two varieties. The treatments consisted of two varieties of coffee (Red Catuaí IAC 144 and IAC 125 RN) and coffee leaves in four phenological stages (young leaves, diagnostic, senescent and deciduous). The index leaf of Catuaí Vermelho IAC 144 showed the highest photosynthetic rate and stomatal conductance, while the internal conductance of CO2 was higher in young and senescent leaves, and the index and senescent leaves showed the highest efficiencies in the use of water. The chlorophyll a, b and total chlorophyll has higher concentrations in the index leaf, while the highest carotenoids occurred in young and senescent leaves. The highest levels of N, P, K and Zn in Catuaí Vermelho IAC 144 was occurred in young leaves and the highest Ca and Fe in senescent leaves. The highest levels of N, P and K in the IAC 125 RN variety was occurred in young leaves, Ca and Mg in deciduous leaves and S in senescent and deciduous leaves. Nutrients with low mobility in the plant must be parceled, the application of Zn leaves is an alternative method of supplying this nutrient, as it has retranslocation via phloem

Leaf canopy display, stomatal conductance, and photosynthesis in seedlings of three tropical pioneer tree species subjected to drought

1992 ◽  
Vol 70 (12) ◽  
pp. 2334-2338 ◽  
Author(s):  
E. G. Reekie ◽  
P. Wayne
Keyword(s):  
Soil Moisture ◽  
Stomatal Conductance ◽  
Relative Humidity ◽  
Turgor Pressure ◽  
Leaf Size ◽  
Net Photosynthesis ◽  
Fibre Content ◽  
Canopy Architecture ◽  
Species Response ◽  
Cecropia Obtusifolia

Seedlings of Piper aurtitum, Cecropia obtusifolia, and Trichospermum mexicanum, pioneer species of lowland tropical rainforests, were subjected to controlled drought cycles, with stomatal conductance and net photosynthesis monitored to determine species response. The affect of soil moisture on canopy display and the response of stomatal conductance to fluctuations in humidity, light, and temperature were also measured. Stomatal conductance and photosynthesis in Piper and Cecropia showed no relationship with soil moisture until it declined to approximately 20%. At higher soil moistures, stomatal conductance in Piper and Cecropia was positively correlated with relative humidity. In contrast, Trichospermum stomatal conductance and photosynthesis showed no relationship with relative humidity and declined gradually as soil moisture decreased. Canopy display in all three species showed a sharp decline at the end of the drought cycle. There were marked differences among species in canopy structure. Piper and Cecropia both have large leaves and a low fibre content in stems, petioles, and leaves, whereas Trichospermum has much smaller leaves and a higher fibre content. In addition, Piper has a higher leaf to stem ratio than Trichospermum. Differences among species in response of stomatal conductance and photosynthesis to environmental factors may reflect the need to maintain a relatively high turgor pressure in Piper and Cecropia for canopy display. Key words: canopy architecture, drought stress, leaf size, Piper auritum, Cecropia obtusifolia, Trichospermum mexicanum.

Growth and Physiological Responses of Soybean Under Various Thermoperiods

1977 ◽  
Vol 4 (3) ◽  
pp. 371 ◽  
Author(s):  
IJ Warrington ◽  
M Peet ◽  
DT Patterson ◽  
J Bunce ◽  
RM Haslemore ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Oxidase Activity ◽  
Dark Period ◽  
Dark Respiration ◽  
Soluble Sugar ◽  
Net Photosynthesis ◽  
Specific Leaf Weight ◽  
Leaf Weight ◽  
Glycollate Oxidase

Diurnal changes in net photosynthesis, dark respiration, specific leaf weight, leaf water potential, stomatal conductance, starch and soluble sugar concentrations, and the activities of malate dehydro- genase and glycollate oxidase were measured in soybeans grown in 23/23,26/20 and 29/17°C thermo- periods, to determine their relationship to thermoperiodic effects on plant growth. Soybean height and main stem leaf number were significantly higher under the constant daylnight (23/23°C) temperature regime. Leaf, stem and root dry weights, and specific leaf weight were all highest where the day/night temperature differential was greatest (29/17°C). Differences in net photosynthesis, dark respiration, starch and soluble sugar concentration, and malate dehydrogenase activity were small between the thermoperiod treatments. However, glycollate oxidase activity was higher under the constant-temperature conditions. Starch concentration, specific leaf weight, and glycollate oxidase activity all increased throughout the photoperiod and subsequently decreased through the dark period. Net photosynthesis declined throughout the photoperiod and both dark respiration and malate dehydrogenase activity peaked at the beginning of the dark period. Each of these diurnal responses was similar under each thermoperiod. Leaf water potential and stomatal conductance did not differ between thermoperiods.

Photosynthetic responses of three C4 grasses of different metabolic subtypes to water deficit

2007 ◽  
Vol 34 (3) ◽  
pp. 204 ◽  
Author(s):  
Ana E. Carmo-Silva ◽  
Ana S. Soares ◽  
Jorge Marques da Silva ◽  
Anabela Bernardes da Silva ◽  
Alfred J. Keys ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Deficit ◽  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Cynodon Dactylon ◽  
Net Photosynthesis ◽  
C3 Plants ◽  
C4 Grasses ◽  
Natural Habitats ◽  
Bisphosphate Carboxylase

C4 plants are considered to be less sensitive to drought than C3 plants because of their CO2 concentrating mechanism. The C4 grasses, Paspalum dilatatum Poiret (NADP-ME), Cynodon dactylon (L.) Pers (NAD-ME) and Zoysia japonica Steudel (PEPCK) were compared in their response to water deficit imposed by the addition of polyethylene glycol to the nutrient solution in which they were grown. The effects of drought on leaf relative water content (RWC), net photosynthesis, stomatal conductance, carboxylating enzyme activities and chlorophyll a fluorescence were investigated. In C. dactylon the RWC was more sensitive, but the photosynthetic activity was less sensitive, to water deficit than in P. dilatatum and Z. japonica. The decrease of photosynthesis in P. dilatatum under water deficit was not closely related to the activities of the carboxylating enzymes or to chlorophyll a fluorescence. However, decreased activities of ribulose 1,5-bisphosphate carboxylase/oxygenase and phosphoenolpyruvate carboxylase, in addition to decreased stomatal conductance, may have contributed to the decrease of photosynthesis with drought in C. dactylon and Z. japonica. The different responses to water deficit are discussed in relation to the natural habitats of C4 grasses.

Net photosynthesis and stomatal conductance of red spruce twigs before and after twig detachment

1993 ◽  
Vol 23 (4) ◽  
pp. 716-721 ◽  
Author(s):  
Fan-Rui Meng ◽  
Paul A. Arp
Keyword(s):  
Stomatal Conductance ◽  
Relative Humidity ◽  
New Brunswick ◽  
Photosynthetically Active Radiation ◽  
Regression Models ◽  
Net Photosynthesis ◽  
Leaf Temperature ◽  
Red Spruce ◽  
Active Radiation ◽  
Before And After

Rates of net photosynthesis and stomatal conductance of red spruce (Picearubens Sarg.) twigs were measured in field conditions before and after twig detachment on clear midsummer days in New Brunswick. Although these variables did not change significantly within about 6 min after twig detachment, they did drop continually after detachment. Regression models for the rates of net photosynthesis and stomatal conductance were developed that can be used to simulate this drop. Photosynthetically active radiation, leaf temperature, relative humidity, and CO2 concentration were the principal covariates in these models. The regressions improved by including simulated leaf moisture values in the analysis of data obtained after twig detachment.

Red spruce seedling gas exchange in response to elevated CO2, water stress, and soil fertility treatments

1994 ◽  
Vol 24 (5) ◽  
pp. 954-959 ◽  
Author(s):  
L.J. Samuelson ◽  
J.R. Seiler
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Soil Fertility ◽  
Net Photosynthesis ◽  
Growing Season ◽  
Red Spruce ◽  
Fertility Treatment ◽  
Sink Strength ◽  
Growth Enhancement ◽  
Growing Seasons

The interactive influences of ambient (374 μL•L−1) or elevated (713 μL•L−1) CO2, low or high soil fertility, well-watered or water-stressed treatment, and rooting volume on gas exchange and growth were examined in red spruce (Picearubens Sarg.) grown from seed through two growing seasons. Leaf gas exchange throughout two growing seasons and growth after two growing seasons in response to elevated CO2 were independent of soil fertility and water-stress treatments, and rooting volume. During the first growing season, no reduction in leaf photosynthesis of seedlings grown in elevated CO2 compared with seedlings grown in ambient CO2 was observed when measured at the same CO2 concentration. During the second growing season, net photosynthesis was up to 21% lower for elevated CO2-grown seedlings than for ambient CO2-grown seedlings when measured at 358 μL•L−1. Thus, photosynthetic acclimation to growth in elevated CO2 occurred gradually and was not a function of root-sink strength or soil-fertility treatment. However, net photosynthesis of seedlings grown and measured at an elevated CO2 concentration was still over 2 times greater than the photosynthesis of seedlings grown and measured at an ambient CO2 concentration. Growth enhancement by CO2 was maintained, since seedlings grown in elevated CO2 were 40% larger in both size and weight after two growing seasons.

Observations On Subsurface Distributions Of Chlorophyll a And Phytoplankton Carbon In The Northeast Pacific Ocean

1974 ◽  
Vol 31 (12) ◽  
pp. 1919-1925 ◽  
Author(s):  
Louis A. Hobson ◽  
Dawn E. Ketcham
Keyword(s):  
Pacific Ocean ◽  
Chlorophyll A ◽  
Net Photosynthesis ◽  
Vancouver Island ◽  
Taxonomic Composition ◽  
Northeast Pacific ◽  
Northeast Pacific Ocean

Measurements of subsurface concentrations of chlorophyll a and phytoplankton carbon were made between Vancouver Island and Hawaii during summer 1971. In general, chlorophyll a concentrations increased and concentrations of phytoplankton carbon decreased from 10 m to depths varying between 100 and 150 m. These distributions indicated that cellular contents of chlorophyll a increased as cells were exposed to diminishing daily irradiations. Daily compensation irradiations for net photosynthesis of subsurface phytoplankton in the northeast Pacific Ocean were estimated in summer 1973. Values ranged between 0.5 and 0.7 cal cm−2 but variability among replicates was large giving a range of 0 and 1.2 cal cm−2. It was not possible to correlate compensation irradiations with taxonomic composition of phytoplankton populations.

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