Abstract
Perennial ryegrass swards were grown in large containers on a soil, at two N fertilizer supplies and were exposed during two years in highly ventilated plastic tunnels to elevated (700 μl l−1 [CO2) or ambient atmospheric CO2 concentration at outdoor temperature and to a 3°C increase in air temperature in elevated CO2. The irrigation was adjusted to obtain a soil water deficit during summer. The daily net C assimilation was increased in elevated CO2 by 29 and 36% at the low and high N supplies, respectively. Canopies grown in elevated CO2 for 14 to 27 months photosynthetized significantly less rapidly, in both elevated and normal CO2 concentrations, than their counterparts developed in ambient CO2 but the magnitude of this effect was small (−8% to −13%). Elevated CO2 resulted in a large increase in the fructan concentration in the pseudostems and laminae (+46% and +189%, respectively). In elevated CO2, the hexose and sucrose pool increased by 28% in the laminae, whereas it did not vary significantly in the pseudo-stems. A 3°C temperature increase in elevated CO2 did not affect significantly the average WSC concentrations in the pseudostems and laminae. The elevated CO2 effects on the net C assimilation and on the nocturnal shoot respiration were greater in summer than in spring. On average, a 35% increase in the below-ground respiration was measured in elevated CO2. At the high N supply, a 3°C increase in air temperature led to a decline in the below-ground respiration due to a low soil moisture. The below-ground carbon storage was increased by 32% and 96% in elevated CO2 at the low and high N supplies, respectively, with no significant increased temperature effect. The role for the below-ground carbon storage of CO2-induced changes in the root fraction of the grass and of temperature-induced changes in the moisture content of the soil are discussed.
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Claims 14
Claim · model-written summary
Elevated CO2 increased daily net C assimilation of perennial ryegrass swards by 29% at the low N supply compared with ambient CO2.
- Taxon
- Perennial ryegrass
Lolium perennee0 - Treatment
- elevated CO2e2
- Outcome
- daily net C assimilatione2
- Direction
- increasede2
- Value
- 29e2
- Qualifier
- low and high N suppliese2
- Comparator
- ambient atmospheric CO2 concentratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“ambient atmospheric CO2 concentration”
e2“The daily net C assimilation was increased in elevated CO2 by 29 and 36% at the low and high N supplies, respectively”
Claim · model-written summary
Elevated CO2 increased daily net C assimilation of perennial ryegrass swards by 36% at the high N supply compared with ambient CO2.
- Taxon
- Perennial ryegrassLolium perennee0
- Treatment
- elevated CO2e2
- Outcome
- daily net C assimilatione2
- Direction
- increasede2
- Value
- 36%e2
- Qualifier
- low and high N suppliese2
- Comparator
- ambient atmospheric CO2 concentratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“ambient atmospheric CO2 concentration”
e2“The daily net C assimilation was increased in elevated CO2 by 29 and 36% at the low and high N supplies, respectively”
Claim · model-written summary
Canopies grown in elevated CO2 for 14 to 27 months photosynthesised significantly less rapidly than canopies developed in ambient CO2, by a small magnitude of 8% to 13%.
- Taxon
- Perennial ryegrassLolium perennee0
- Treatment
- elevated CO2 for 14 to 27 monthse1
- Outcome
- photosynthetizede1
- Direction
- less rapidlye1
- Value
- −8% to −13%e2
- Comparator
- ambient CO2e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“Canopies grown in elevated CO2 for 14 to 27 months photosynthetized significantly less rapidly, in both elevated and normal CO2 concentrations, than their counterparts developed in ambient CO2”
e2“−8% to −13%”
Claim · model-written summary
Elevated CO2 increased fructan concentration in ryegrass pseudostems by 46%.
- Taxon
- Perennial ryegrassLolium perennee0
- Organ / stage
- pseudostemse2
- Treatment
- Elevated CO2e2
- Outcome
- fructan concentratione2
- Direction
- increasee2
- Value
- +46%e2
- Comparator
- ambient atmospheric CO2 concentratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“ambient atmospheric CO2 concentration”
e2“Elevated CO2 resulted in a large increase in the fructan concentration in the pseudostems and laminae (+46% and +189%, respectively)”
Claim · model-written summary
Elevated CO2 increased fructan concentration in ryegrass laminae by 189%.
- Taxon
- Perennial ryegrassLolium perennee0
- Organ / stage
- laminaee2
- Treatment
- Elevated CO2e2
- Outcome
- fructan concentratione2
- Direction
- increasee2
- Value
- +189%e2
- Comparator
- ambient atmospheric CO2 concentratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“ambient atmospheric CO2 concentration”
e2“Elevated CO2 resulted in a large increase in the fructan concentration in the pseudostems and laminae (+46% and +189%, respectively)”
Claim · model-written summary
In elevated CO2 the hexose and sucrose pool increased by 28% in ryegrass laminae.
- Taxon
- Perennial ryegrassLolium perennee0
- Organ / stage
- laminaee2
- Treatment
- elevated CO2e2
- Outcome
- hexose and sucrose poole2
- Direction
- increasede2
- Value
- 28%e2
- Comparator
- ambient atmospheric CO2 concentratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“ambient atmospheric CO2 concentration”
e2“In elevated CO2, the hexose and sucrose pool increased by 28% in the laminae, whereas it did not vary significantly in the pseudo-stems”
Claim · model-written summary
In elevated CO2 the hexose and sucrose pool did not vary significantly in ryegrass pseudo-stems.
- Taxon
- Perennial ryegrassLolium perennee0
- Organ / stage
- pseudo-stemse2
- Treatment
- elevated CO2e2
- Outcome
- hexose and sucrose poole2
- Direction
- did not vary significantlye2
- Comparator
- ambient atmospheric CO2 concentratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“ambient atmospheric CO2 concentration”
e2“In elevated CO2, the hexose and sucrose pool increased by 28% in the laminae, whereas it did not vary significantly in the pseudo-stems”
Claim · model-written summary
A 3 C air temperature increase in elevated CO2 did not significantly affect average WSC concentrations in pseudostems and laminae.
- Taxon
- Perennial ryegrassLolium perennee0
- Organ / stage
- pseudostems and laminaee1
- Treatment
- A 3°C temperature increasee1
- Outcome
- average WSC concentrationse1
- Direction
- did not affect significantlye1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“A 3°C temperature increase in elevated CO2 did not affect significantly the average WSC concentrations in the pseudostems and laminae”
Claim · model-written summary
The elevated CO2 effects on net C assimilation and nocturnal shoot respiration were greater in summer than in spring.
- Taxon
- Perennial ryegrassLolium perennee0
- Treatment
- elevated CO2e1
- Outcome
- net C assimilation and on the nocturnal shoot respiratione1
- Direction
- greatere1
- Qualifier
- in summer than in springe1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“The elevated CO2 effects on the net C assimilation and on the nocturnal shoot respiration were greater in summer than in spring”
Claim · model-written summary
Below-ground respiration rose on average by 35% in elevated CO2.
- Taxon
- Perennial ryegrassLolium perennee0
- Treatment
- elevated CO2e2
- Outcome
- below-ground respiratione2
- Direction
- increasee2
- Value
- 35%e2
- Comparator
- ambient atmospheric CO2 concentratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“ambient atmospheric CO2 concentration”
e2“On average, a 35% increase in the below-ground respiration was measured in elevated CO2”
Claim · model-written summary
At the high N supply a 3 C air temperature increase led to a decline in below-ground respiration, due to low soil moisture.
- Taxon
- Perennial ryegrassLolium perennee0
- Treatment
- a 3°C increase in air temperaturee1
- Outcome
- below-ground respiratione1
- Direction
- declinee1
- Qualifier
- At the high N supplye1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“At the high N supply, a 3°C increase in air temperature led to a decline in the below-ground respiration due to a low soil moisture”
Claim · model-written summary
Elevated CO2 increased below-ground carbon storage by 32% at the low N supply.
- Taxon
- Perennial ryegrassLolium perennee0
- Treatment
- elevated CO2e2
- Outcome
- below-ground carbon storagee2
- Direction
- increasede2
- Value
- 32%e2
- Qualifier
- low and high N suppliese2
- Comparator
- ambient atmospheric CO2 concentratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“ambient atmospheric CO2 concentration”
e2“The below-ground carbon storage was increased by 32% and 96% in elevated CO2 at the low and high N supplies, respectively”
Claim · model-written summary
Elevated CO2 increased below-ground carbon storage by 96% at the high N supply.
- Taxon
- Perennial ryegrassLolium perennee0
- Treatment
- elevated CO2e2
- Outcome
- below-ground carbon storagee2
- Direction
- increasede2
- Value
- 96%e2
- Qualifier
- low and high N suppliese2
- Comparator
- ambient atmospheric CO2 concentratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“ambient atmospheric CO2 concentration”
e2“The below-ground carbon storage was increased by 32% and 96% in elevated CO2 at the low and high N supplies, respectively”
Claim · model-written summary
Below-ground carbon storage showed no significant effect of increased temperature.
- Taxon
- Perennial ryegrassLolium perennee0
- Treatment
- increased temperaturee1
- Direction
- no significante1
Not reportedComparatorOutcome
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Perennial ryegrass swards”
e1“with no significant increased temperature effect”
The same questions in other papers
co2 · physiology: photosynthesis · Lolium perenne (perennial ryegrass)Positive and negative results
2 papers in the same direction as this paper · 4 in the opposite direction
- positive
- positive
- positive
3 papers more in this group
See all 7 papers →co2 · molecular: metabolites · Lolium perenne (perennial ryegrass)Results agree
1 paper in the same direction as this paper
- positive
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.