Intervention effectmodel-written summary

Whole-plant photosynthetic rate was 8% lower at 2600 micromoles mol-1 CO2 than at ambient CO2.

A claim from Very High CO2Reduces Photosynthesis, Dark Respiration and Yield in Wheat · 1997

Intervention effectobservedoriginal resultnegativemeasured

Claim · model-written summary

Taxon: wheatTriticum aestivume0
Treatment: 2600 micromoles mol-1 CO2e0
Outcome: photosynthetic ratee0
Direction: lowere0
Value: 8%e0
Comparator: ambient [CO2]e0

Not reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleSettingQualifier

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

*Triticum aestivum* · TaxonRasbak · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

e0
“The photosynthetic rate of whole wheat plants was 8% lower and dark respiration of the wheat heads 25% lower when exposed to 2600 micromoles mol-1 CO2 compared to ambient [CO2]”
✓ located verbatim in the source · abstract, characters 1688–1864

Title

Very High CO2Reduces Photosynthesis, Dark Respiration and Yield in Wheat

J REUVENI Annals of Botany 1997. doi:10.1006/anbo.1997.0489

Other claims from this paper (16)

Intervention effect Raising CO2 from 350 to 1000 micromoles mol-1 increased wheat seed yield by 33%.
Intervention effect Raising CO2 from 350 to 1000 micromoles mol-1 increased vegetative biomass by 25%.
Intervention effect Raising CO2 from 350 to 1000 micromoles mol-1 increased heads per square meter by 34%.
Intervention effect Increasing CO2 from 1000 to 10000 micromoles mol-1 decreased seed yield by 37%.
Intervention effect Increasing CO2 from 1000 to 10000 micromoles mol-1 decreased harvest index by 14%.
Intervention effect Increasing CO2 from 1000 to 10000 micromoles mol-1 decreased mass per seed by 9%.
Intervention effect Increasing CO2 from 1000 to 10000 micromoles mol-1 decreased seeds per head by 29%.
Intervention effect Very high CO2 had negligible, nonsignificant effects on vegetative biomass, heads per square meter, and seed mass per head.
Intervention effect Seed yield, harvest index and seeds per head sharply decreased between 1000 and 2600 micromoles mol-1 CO2.
Intervention effect Further raising CO2 from 2600 to 10000 micromoles mol-1 produced a smaller further decrease in those yield traits.
Observation The two wheat cultivars responded similarly to CO2 across growth parameters.
Observation Wheat grown in the two cultivation environments did not differ in response to high CO2.
Association High CO2 was not correlated with ethylene production by wheat flag leaves or heads.
Intervention effect Wheat head dark respiration was 25% lower at 2600 micromoles mol-1 CO2 than at ambient CO2.
Mechanism The authors attribute reduced seed set mainly to reduced dark respiration in wheat heads.
Mechanism The authors conclude that ethylene does not mediate reduced wheat seed set.

Record rev-5335d2602bba60eaecfe05a1d5f794a1a0bfc7e0cadf4698d2bcbac05c72c1ec · schema claims-v0.9 · position 14 in the model’s answer

co2 · physiology: photosynthesis · Triticum aestivum (wheat)Positive and negative results

97 papers: 69 positive, 28 negative or no effect

27 papers in the same direction as this claim · 69 in the opposite direction

positive
Apparent photosynthesis increased 50%.
CO₂‐Enrichment Effects on Wheat Yield and Physiology¹ · 1984
Opposite directionCited by this paper
positive
Net canopy photosynthesis was stimulated by an average 19 and 44% in the Wet and Dry plots, respectively, by elevated [CO 2 ] for most of the growing season.
Productivity and water use of wheat under free‐air CO₂ enrichment · 1995
Opposite direction
positive
wheat photosynthesis, AQE and WUE increased with elevated CO2.
Interaction of Elevated Ultraviolet-B Radiation and CO₂ on Productivity and Photosynthetic Characteristics in Wheat, Rice, and Soybean · 1990
Opposite direction
positive
Leaves grown at 700 μmol mol −1 CO2 had slightly greater photosynthetic capacity, about 10% higher on average, than those at ambient CO2.
Interacting effects of CO₂ concentration, temperature and nitrogen supply on the photosynthesis and composition of winter wheat leaves · 1994 · compared with ambient CO 2 concentration
Opposite direction
positive
Elevated CO2 raised seasonal midday photosynthesis by 28%.
Photosynthesis and conductance of spring‐wheat leaves: field response to continuous free‐air atmospheric CO₂ enrichment · 1998 · compared with contols
Opposite direction
positive
Elevated CO2 sustained an increase in canopy quantum yield.
Adaptation to high CO₂ concentration in an optimal environment: radiation capture, canopy quantum yield and carbon use efficiency · 1998
Opposite direction
positive
Photosynthesis under saturating irradiances was increased by up to 100% at 680 μmol mol–1 CO2 relative to the ambient CO2 control.
Impact of elevated atmospheric CO₂and O₃on gas exchange and chlorophyll content in spring wheat (Triticum aestivumL.) · 1997 · compared with ambient CO2 control
Opposite direction
positive
In situ wheat photosynthetic CO2 uptake remained higher under elevated CO2.
Does Leaf Position within a Canopy Affect Acclimation of Photosynthesis to Elevated CO2?1 · 1998
Opposite direction

88 papers more in this group

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Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.

Other papers on the same question

co2 · physiology: photosynthesis · Triticum aestivum (wheat)Positive and negative results