Abstract
Abstract Seedlings of Phleum pratense L. (timothy) of the same age were grown in five sequential four-week periods during one growth season (May 5-September 23) at low (380 μmol mol−1) and high (650 μmol mol−1) CO2 concentration. The experiment was performed in 10 9 m2field plots surrounded by plastic foil walls (“field chambers”) in the relatively cool climate (10-13°C mean temperature) of the west coast of Norway (59°N latitude). Raising the CO2 concentration generally decreased the height of the grass (8-23%), especially at the beginning and end of the growth season The number of shoots was significantly increased (13-42%) by CO2enrichment in all growth periods except the last. Elevated CO2 did not influence the above-ground biomass (dry weight) in the first (May) and last (September) period, but increased it by 14-51% in the intervening periods (June-August). Positive effects of CO2 enrichment on plant biomass were correlated with positive effects on the number of shoots. Elevated CO2 concentrations resulted in 25-64% denser plant biomass (dry weight per unit air volume) in the different growth periods. In general, a positive “chamber effect” on plant height and dry weight was found in spite of the small air temperature differences between the insides and the outsides of the chambers. A greenhouse experiment showed that wind speeds above 3 m s−1 strongly decreased height and dry weight of timothy seedlings. The reduced wind speeds inside the chambers could therefore explain the “chamber effects” found. Key Words: climatemorphogenesis
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Elevated CO2 generally reduced timothy height by 8-23%, especially at the start and end of the season.
- Taxon
- Phleum pratense L.
Phleum pratensee0 - Treatment
- Raising the CO2 concentratione1
- Outcome
- height of the grasse1
- Direction
- decreasede1
- Value
- 8-23%e1
- Qualifier
- especially at the beginning and end of the growth seasone1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Seedlings of Phleum pratense L. (timothy)”
e1“Raising the CO2 concentration generally decreased the height of the grass (8-23%), especially at the beginning and end of the growth season”
Claim · model-written summary
CO2 enrichment significantly increased timothy shoot number by 13-42%, except in the last growth period.
- Taxon
- Phleum pratense L.Phleum pratensee0
- Treatment
- CO2enrichmente1
- Outcome
- number of shootse1
- Direction
- increasede1
- Value
- 13-42%e1
- Qualifier
- in all growth periods except the laste1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Seedlings of Phleum pratense L. (timothy)”
e1“The number of shoots was significantly increased (13-42%) by CO2enrichment in all growth periods except the last.”
Claim · model-written summary
Elevated CO2 did not influence timothy above-ground dry biomass in May and September.
- Taxon
- Phleum pratense L.Phleum pratensee0
- Treatment
- Elevated CO2e1
- Outcome
- above-ground biomass (dry weight)e1
- Direction
- did not influencee1
- Qualifier
- first (May) and last (September) periode1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Seedlings of Phleum pratense L. (timothy)”
e1“Elevated CO2 did not influence the above-ground biomass (dry weight) in the first (May) and last (September) period”
Claim · model-written summary
Elevated CO2 increased timothy above-ground biomass by 14-51% in June-August.
- Taxon
- Phleum pratense L.Phleum pratensee0
- Treatment
- Elevated CO2e2
- Outcome
- above-ground biomasse2
- Direction
- increasede1
- Value
- 14-51%e1
- Qualifier
- intervening periods (June-August)e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Seedlings of Phleum pratense L. (timothy)”
e1“but increased it by 14-51% in the intervening periods (June-August)”
e2“Elevated CO2 did not influence the above-ground biomass (dry weight) in the first (May) and last (September) period”
Claim · model-written summary
Positive biomass effects of CO2 enrichment were correlated with positive effects on shoot number.
- Taxon
- Phleum pratense L.Phleum pratensee0
- Treatment
- CO2 enrichmente1
- Outcome
- plant biomasse1
- Direction
- Positive effectse1
- Qualifier
- positive effects on the number of shootse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Seedlings of Phleum pratense L. (timothy)”
e1“Positive effects of CO2 enrichment on plant biomass were correlated with positive effects on the number of shoots.”
Claim · model-written summary
Elevated CO2 made timothy biomass 25-64% denser across growth periods.
- Taxon
- Phleum pratense L.Phleum pratensee0
- Treatment
- Elevated CO2 concentrationse1
- Outcome
- plant biomass (dry weight per unit air volume)e1
- Direction
- densere1
- Value
- 25-64%e1
- Qualifier
- different growth periodse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Seedlings of Phleum pratense L. (timothy)”
e1“Elevated CO2 concentrations resulted in 25-64% denser plant biomass (dry weight per unit air volume) in the different growth periods.”
Claim · model-written summary
Field chambers increased timothy plant height.
- Taxon
- Phleum pratense L.Phleum pratensee0
- Treatment
- “chamber effect”e1
- Outcome
- plant heighte1
- Direction
- positivee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Seedlings of Phleum pratense L. (timothy)”
e1“a positive “chamber effect” on plant height and dry weight was found”
Claim · model-written summary
Field chambers increased timothy dry weight.
- Taxon
- Phleum pratense L.Phleum pratensee0
- Treatment
- “chamber effect”e1
- Outcome
- dry weighte1
- Direction
- positivee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Seedlings of Phleum pratense L. (timothy)”
e1“a positive “chamber effect” on plant height and dry weight was found”
Claim · model-written summary
Wind speeds above 3 m s−1 strongly decreased timothy seedling height in a greenhouse.
- Taxon
- timothyPhleum pratensee1
- Treatment
- wind speeds above 3 m s−1e1
- Outcome
- heighte1
- Direction
- decreasede1
- Setting
- greenhousee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Seedlings of Phleum pratense L. (timothy)”
e1“A greenhouse experiment showed that wind speeds above 3 m s−1 strongly decreased height and dry weight of timothy seedlings.”
Claim · model-written summary
Wind speeds above 3 m s−1 strongly decreased timothy seedling dry weight in a greenhouse.
- Taxon
- timothyPhleum pratensee1
- Treatment
- wind speeds above 3 m s−1e1
- Outcome
- dry weighte1
- Direction
- decreasede1
- Setting
- greenhousee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A greenhouse experiment showed that wind speeds above 3 m s−1 strongly decreased height and dry weight of timothy seedlings.”
The same questions in other papers
co2 · growth · Phleum pratense (timothy)Results differ
2 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
- 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.