Effects of pretreatment temperature on carbon dioxide exchange in alfalfa

1972 ◽  
Vol 50 (9) ◽  
pp. 1925-1930 ◽  
Author(s):  
C. J. Pearson ◽  
L. A. Hunt
Keyword(s):  
Carbon Dioxide ◽  
Temperature Response ◽  
Day Length ◽  
Carbon Dioxide Exchange ◽  
Response Curves ◽  
Free Atmosphere ◽  
Pretreatment Temperature ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
The Relationship

The temperature response curves for net carbon dioxide exchange are described for plants of cultivars (cvs.) Vernal and Moapa alfalfa (Medicago sativa L.) grown at day/night temperatures of 30/25C and 20/15C, an irradiance of 25 nE cm−2 s−1 (400–700 nm), and a day length of 15.5 h. Net carbon dioxide intake (NCI) of the tops decreased with increasing temperature from 20 mg dm−2 h−1 at 10C to 5 mg dm−2 h−1 at 40C. The nature of the NCI-temperature response curve was affected by pretreatment temperature, with NCI being lower at all temperatures except 10C after growth at 20/15C. Photorespiration, which reached its maximum value at a higher temperature (20–30C) than that required for maximum NCI, accounted for 22% of the gross carbon dioxide intake (net carbon dioxide exchange in an oxygen-free atmosphere) at 10C and 55% at 40C. Pretreatment affected the relationship between net carbon dioxide output (NCO) and temperature, with NCO being higher at 10C but lower at 30C after growth at 20/15C as compared to 30/25C.

EFFECT OF TEMPERATURE ON NET CARBON DIOXIDE EXCHANGE RATES OF TWELVE BARLEY VARIETIES

1968 ◽  
Vol 48 (4) ◽  
pp. 363-368 ◽  
Author(s):  
D. P. Ormrod ◽  
W. F. Hubbard ◽  
D. G. Faris
Keyword(s):  
Carbon Dioxide ◽  
Exchange Rates ◽  
Effect Of Temperature ◽  
Carbon Dioxide Exchange ◽  
Controlled Environment ◽  
Response Curves ◽  
Gradual Decline ◽  
Carbon Dioxide Uptake ◽  
Higher Temperature ◽  
Increasing Temperature

Seedlings of 12 barley varieties were grown in a controlled environment to 21 days of age and then transferred to an apparatus for measuring net carbon dioxide exchange rates. Rates were measured at temperatures ranging from 4 to 34 °C and the results were plotted to provide a response curve for each variety. The response curves were not clearly different between varieties, but some trends were evident. The varieties Husky, Parkland and Vantmore had response curves of similar shape with marked increases with increasing temperature to 14 to 18 °C. Asa, Olli and Pirkka showed a more gradual rise to about 20 °C. Varieties O.A.C. 21, Vantage and Wolfe showed a very rapid increase in carbon dioxide uptake to about 6 °C followed by very little change to 20 °C, leading into a gradual decline. Stavropol, Trebi and White Gatami had maximum rates at a higher temperature. The patterns presented by the varieties may be related to different areas of origin and production. Varieties were markedly different at low temperatures but differed little in response to temperatures near 34 °C. Absolute rates of net carbon dioxide exchange differed markedly among varieties.

scholarly journals Exploring the Relationship between Abundance and Temperature with a Chemostat Model

2016 ◽  
Author(s):  
Cristian A. Solari ◽  
Vanina J. Galzenati ◽  
Brian J. McGill
Keyword(s):  
Mortality Rate ◽  
High Mortality ◽  
Response Curve ◽  
Temperature Response ◽  
Response Curves ◽  
Chemostat Model ◽  
Half Saturation Constant ◽  
Limiting Nutrient ◽  
Response To Temperature ◽  
The Relationship

AbstractAlthough there is a well developed theory on the relationship between the intrinsic growth rate r and temperature T, it is not yet clear how r relates to abundance, and how abundance relates to T. Many species often have stable enough population dynamics that one can talk about a stochastic equilibrium population size N*. There is sometimes an assumption that N* and r are positively correlated, but there is lack of evidence for this. To try to understand the relationship between r, N*, and T we used a simple chemostat model. The model shows that N* not only depends on r, but also on the mortality rate, the half-saturation constant of the nutrient limiting r, and the conversion coefficient of the limiting nutrient. Our analysis shows that N* positively correlates to r only with high mortality rate and half-saturation constant values. The response curve of N* vs. T can be flat, Gaussian, convex, and even temperature independent depending on the values of the variables in the model and their relationship to T. Moreover, whenever the populations have not reached equilibrium and might be in the process of doing so, it could be wrongly concluded that N* and r are positively correlated. Because of their low half-saturation constants, unless conditions are oligotrophic, microorganisms would tend to have flat abundance response curves to temperature even with high mortality rates. In contrast, unless conditions are eutrophic, it should be easier to get a Gaussian temperature response curve for multicellular organisms because of their high half-saturation constant. This work sheds light to why it is so difficult for any general principles to emerge on the abundance response to temperature. We conclude that directly relating N* to r is an oversimplification that should be avoided.

Temperature Response of Whole-plant CO2 Exchange Rates of Magnolia (Magnolia grandiflora L.)

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 511d-511
Author(s):  
Marc W. van Iersel ◽  
Orville M. Lindstrom
Keyword(s):  
Dark Respiration ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
Co2 Exchange ◽  
Limiting Factor ◽  
Response Curves ◽  
Gross Photosynthesis ◽  
Temperature Range ◽  
Whole Plant ◽  
Increasing Temperature

Photosynthesis and respiration temperature-response curves are useful in predicting the ability of plants to perform under different environmental conditions. Whole crop CO2 exchange of two groups of magnolia `Greenback' plants was measured over a 26 °C temperature range. Net photosynthesis (Pnet) increased from 2 to 17% C and decreased again at higher temperatures. The Q10 for Pnet decreased from ≈4 at 6 °C to 0.5 at 24 °C. The decrease in Pnet at temperatures over 17 °C was caused by a rapid increase in dark respiration (Rdark) with increasing temperature. The Q10 for Rdark was estimated by fitting an exponential curve to data, resulting in a temperature-independent Q10 of 2.8. Gross photosynthesis (Pgross), estimated as the sum of Rdark and Pnet, increased over the entire temperature range (up to 25 °C). The Q10 for Pgross decreased with increasing temperature, but remained higher than 1. The data suggest that high respiration rates may be the limiting factor for growth of magnolia exposed to high temperatures, since it may result in a net carbon loss from the plants. At temperatures below 5 °C, both Pnet and Rdark become low and the net CO2 exchange of the plants would be expected to be minimal.

scholarly journals Temperature Response of Whole-plant CO2 Exchange Rates of Three Magnolia Cultivars

1999 ◽  
Vol 124 (3) ◽  
pp. 277-282 ◽  
Author(s):  
Marc W. van Iersel ◽  
Orville M. Lindstrom
Keyword(s):  
Exchange Rates ◽  
Environmental Conditions ◽  
Dark Respiration ◽  
Temperature Response ◽  
Rapid Decline ◽  
Optimal Temperature ◽  
Response Curves ◽  
Gross Photosynthesis ◽  
Temperature Range ◽  
Increasing Temperature

Temperature-response curves for photosynthesis and respiration are useful in predicting the ability of plants to perform under different environmental conditions. Whole crop CO2 exchange rates of three magnolia (Magnolia grandiflora L.) cultivars (`MGTIG', `Little Gem', and `Claudia Wannamaker') were measured over a 25 °C temperature range. Plants were exposed to cool temperatures (13 °C day, 3 °C night) temperatures before the measurements. Net photosynthesis (Pnet) of all three cultivars increased from 3 to 15 °C and decreased again at higher temperatures. `MGTIG' had the highest and `Little Gem' the lowest Pnet, irrespective of temperature. The Q10 (relative increase in the rate of a process with a 10 °C increase in temperature) for Pnet of all three cultivars decreased over the entire temperature range. `MGTIG' had the lowest Q10 at low temperatures (1.4 at 8 °C), while `Little Gem' had the lowest Q10 for Pnet at temperatures >17 °C and a negative Q10 > 23 °C. This indicates a rapid decline in Pnet of `Little Gem' at high temperatures. The decrease in Pnet of all three cultivars at temperatures >15 °C was caused mainly by an exponential increase in dark respiration (Rdark) with increasing temperature. `Little Gem' had a lower Rdark (per unit fresh mass) than `MGTIG' or `Claudia Wannamaker', but all three cultivars had a similar Q10 (2.46). Gross photosynthesis (Pgross) was less sensitive to temperature than Pnet and Rdark. The optimal temperature for Pgross of `MGTIG' was lower (19 °C) than those of `Little Gem' (21 °C) and `Claudia Wannamaker' (22 °C). The Q10 for Pgross decreased with increasing temperature, and was lower for `MGTIG' than for `Little Gem' and `Claudia Wannamaker'. All three cultivars had the same optimal temperature (11 °C) for net assimilation rate (NAR), and NAR was not very sensitive to temperature changes from 3 to 17 °C. This indicates that the plants were well-adapted to their environmental conditions. The results suggest that respiration rate may limit magnolia growth when temperatures get high in winter time.

scholarly journals The Oxygen Uptake of the Lobster (Homarus Vulgaris Edw.)

1954 ◽  
Vol 31 (2) ◽  
pp. 228-251
Author(s):  
H. J. THOMAS
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Oxygen Concentration ◽  
Sea Water ◽  
Carbon Dioxide Concentration ◽  
Ventilation Rate ◽  
Gill Ventilation ◽  
Increasing Temperature ◽  
The Relationship ◽  
Respiratory Movements

1. In sea water the oxygen uptake of Homarus vulgaris is directly proportional to the oxygen concentration. The relationship applies over the temperature range 6-18°C. 2. Within specified limits of size and condition, oxygen uptake is the same for both sexes. 3. The relative oxygen uptake in sea water decreases as the weight of the animal increases. 4. Oxygen uptake in sea water is effected mainly through the gills. The abdominal swimmerets, however, also serve in respiration and account for approximately 3 % of the total oxygen uptake. 5. In sea water of constant oxygen tension, oxygen uptake increases with increasing temperature. 6. Increase in oxygen uptake with temperature in sea water is mainly brought about by an increase in the gill ventilation rate. In addition, the degree of utilization increases. The relationship is a direct reflexion of the increased metabolic activity. 7. The ventilation rate of gills is unaffected by a decrease of oxygen. 8. The percentage of oxygen extracted by the gills increases as the oxygen concentration of the medium decreases. 9. Under the influence of carbon dioxide respiratory movements become retarded at acidities greater than about pH 7.0 and are completely inhibited at around pH 6.5. At acidities less than pH 7.0 changes in the carbon dioxide concentration are without effect on the rate of the respiratory movements. 10. The oxygen uptake in air, notwithstanding its low level, is directly proportional to temperature. 11. The significance of the above results in relation to the respiratory functions of the blood is discussed.

Effects of temperature on the photosynthesis–irradiance response curves of newly matured leaves of alfalfa

1977 ◽  
Vol 55 (8) ◽  
pp. 872-879 ◽  
Author(s):  
S. B. Ku ◽  
L. A. Hunt
Keyword(s):  
Carbon Dioxide ◽  
Stomatal Resistance ◽  
Carbon Dioxide Exchange ◽  
Response Curves ◽  
Oxygen Inhibition ◽  
Thermal Environments ◽  
Growth Regime ◽  
Medicago Sativa L ◽  
Effects Of Temperature ◽  
Mesophyll Resistance

Various carbon dioxide exchange characteristics are described for two alfalfa (Medicago sativa L.) genotypes (AT 171 and CC 120) grown at 20:15 °C and 30:25 °C day:night temperatures and 53 nE cm−2 s−1 irradiance (400–700 nm). Growth at 30:25 °C as compared with 20:15 °C resulted in lower net carbon dioxide exchange rates (NCE) for both genotypes when analyzed at 20 °C, but did not cause any sizeable change for CC 120 at 30 °C. Oxygen inhibition of photosynthesis increased with irradiance to 48 nE cm−2 s−1 but either declined or remained constant with further increase in irradiance. Oxygen inhibition was higher at 30 °C than at 20 °C and was not consistently influenced by growth temperature. However, the ratio of oxygen inhibition to carbon dioxide exchange rate in air containing 1% oxygen and the mesophyll resistance were greater with AT 171 grown at 30:25 °C than at 20:15 °C, particularly at high irradiances. NCE measured at 20 °C instead of 30 °C for plants grown at 30:25 °C was reduced to a much more marked extent with CC 120 than with AT 171; this difference was paralleled by a more marked increase in stomatal resistance length (rSL) for CC 120.rSL decreased with an increase in irradiance, was generally higher at 20 °C than at 30 °C, and did not differ between growth temperatures when measured at an irradiance of 116 nE cm−2 s−1 and a temperature equal to the day temperature of the growth regime. The results are discussed in relation to factors responsible for adaptability to different thermal environments.

scholarly journals A Daylight Climate Chamber for Testing Greenhouse Climate Control Strategies and Calculating Canopy Carbon Dioxide Exchange

2006 ◽  
Vol 16 (2) ◽  
pp. 191-198 ◽  
Author(s):  
Lise T. Jensen ◽  
Jesper M. Aaslyng ◽  
Eva Rosenqvist
Keyword(s):  
Carbon Dioxide ◽  
Air Temperature ◽  
Control Strategies ◽  
Day Length ◽  
Small Scale ◽  
Carbon Dioxide Exchange ◽  
Climate Control ◽  
Climate Chamber ◽  
Greenhouse Climate ◽  
Greenhouse Climate Control

A daylight climate chamber was designed with the aim of testing new greenhouse climate control strategies on a small scale. Precise control and measure ment of the chamber climate and long-term measurement of canopy carbon dioxide (CO2) exchan ge was possible. The software was capable of simulating a climate computer used in a full-scale greenhouse. The parameters controlled were air temperature, CO2 concentration, irradiance, air flow, and irrigation. The chamber was equipped with a range of sensors measuring the climate in the air of the chamber and in the plant canopy. A chamber perfor mance experiment with chrysanthemum (Chrysanthemum grandiflorum `Coral Charm') plants grown in perlite was carried out over the course of 3 weeks. Five air temperature treatments at a day length of 13 hours were carried out, all with the same 24-hour mean temperature of 20 °C, but different day temperatures (18.0 to 25.1 °C) and night temperatures (14.0 to 22.4 °C). Rate of canopy CO2 exchange in the chambers was calculated. In the range of day temperatures used, rates of canopy photosynthesis were almost equal. The results showed that leaf area and plant dry weight after 3 weeks were not significantly different among temperature treatments, which is promising for further investigations of how climate control can be used to decrease energy consumption in greenhouse production.

scholarly journals Interactions between labile carbon, temperature and land use regulate carbon dioxide and methane production in tropical peat

2019 ◽  
Vol 147 (1) ◽  
pp. 87-97 ◽  
Author(s):  
N. T. Girkin ◽  
S. Dhandapani ◽  
S. Evers ◽  
N. Ostle ◽  
B. L. Turner ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Land Use ◽  
Temperature Response ◽  
Total Carbon ◽  
Carbon Addition ◽  
Labile Carbon ◽  
Tropical Peat ◽  
Tropical Peatlands ◽  
Carbon Store ◽  
Increasing Temperature

AbstractTropical peatlands are a significant carbon store and contribute to global carbon dioxide (CO2) and methane (CH4) emissions. Tropical peatlands are threatened by both land use and climate change, including the alteration of regional precipitation patterns, and the 3–4 °C predicted warming by 2100. Plant communities in tropical peatlands can regulate greenhouse gas (GHG) fluxes through labile carbon inputs, but the extent to which these inputs regulate the temperature response of CO2 and CH4 production in tropical peat remains unclear. We conducted an anoxic incubation experiment using three peat types of contrasting botanical origin to assess how carbon addition affects the temperature response (Q10) of CO2 and CH4 production. Peats from forested peatlands in Panama and Malaysia, and a converted oil palm and pineapple intercropping system in Malaysia, differed significantly in redox potential, total carbon and carbon: nitrogen ratio. The production of CO2 and CH4 varied significantly among peat types and increased with increasing temperature, with Q10s for both gases of 1.4. Carbon addition further increased gas fluxes, but did not influence the Q10 for CO2 or CH4 production or significantly affect the Q10 of either gas. These findings demonstrate that the production of CO2 and CH4 in tropical peat is sensitive to warming and varies among peat types, but that the effect of root inputs in altering Q10 appears to be limited.

Studies on the daily course of carbon exchange in alfalfa plants

1972 ◽  
Vol 50 (6) ◽  
pp. 1377-1383 ◽  
Author(s):  
C. J. Pearson ◽  
L. A. Hunt
Keyword(s):  
Carbon Dioxide ◽  
Medicago Sativa ◽  
Dark Period ◽  
Day Length ◽  
Carbon Dioxide Exchange ◽  
Carbon Exchange ◽  
Diurnal Pattern ◽  
Carbon Dioxide Output ◽  
Maximum Value ◽  
Medicago Sativa L

The diurnal pattern of carbon dioxide exchange is described for plants of cultivars Vernal and Moapa alfalfa (Medicago sativa L.) grown at day/night temperatures of 30/25C and 20/15C, an irradiance of 25 nanoEinsteins cm−2 s−1 (400–700 nm), and a day length of 15.5 h. The net carbon dioxide intake (NCI) of the tops reached 90% of its maximum value after 4–5 h of illumination at 20/15C, but after only 1–2 h at 30/25C; by contrast, NCI of the tops declined after 11–14 h from the start of the photoperiod at 20/15C and after 8.5–10.5 h at 30/25C. Net carbon dioxide output (NCO) of the tops increased throughout the dark period at 20/15C, but remained constant at 30/25C. NCO of the roots remained constant throughout the photoperiod at 20/15C, and increased linearly for 4–8 h at 30/25C. Similarly, NCO of the roots remained constant throughout the dark period at 20/15C, but changed with time (decreased) at 30/25C.

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