Abstract
Naturally regenerated 20-25-year-old Scots pine (Pinus sylvestris L.) trees were grown in open-top chambers in the presence of an elevated temperature or CO(2) concentration, or both. The elevated temperature treatment was administered year-round for 3 years. The CO(2) treatment was applied between April 15 and September 15 for 2 years. The photosynthetic responses of 1- and 2-year-old needles to varying photon flux densities (0-1500 micro mol m(-2) s(-1)) and CO(2) concentrations (350, 700 and 1400 micro mol mol(-1)) during measurement were determined. The CO(2) treatment alone increased maximum photosynthetic rate and light-use efficiency, but decreased dark respiration rate, light compensation and light saturation regardless of needle age. In contrast, the temperature treatment decreased maximum photosynthetic rate and photosynthetic efficiency, but increased dark respiration rate, light compensation and light saturation. The aging of needles affected the photosynthetic performance of the shoots; values of all parameters except photosynthetic efficiency were less in 2- than in 1-year-old needles. The CO(2) treatment decreased and the temperature treatment enhanced the reduction in maximum photosynthesis due to needle aging.
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 7
Claim · model-written summary
Elevated CO2 increased maximum photosynthetic rate and light-use efficiency.
- Taxon
- Scots pine
Pinus sylvestrist0 - Treatment
- CO(2) treatmente0
- Outcome
- maximum photosynthetic rate and light-use efficiencye0
- Direction
- increasede0
- Qualifier
- regardless of needle agee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The CO(2) treatment alone increased maximum photosynthetic rate and light-use efficiency, but decreased dark respiration rate, light compensation and light saturation regardless of needle age”
t0“Scots pine”
Claim · model-written summary
Elevated CO2 decreased dark respiration, light compensation and light saturation.
- Taxon
- Scots pinePinus sylvestrist0
- Treatment
- CO(2) treatmente0
- Outcome
- dark respiration rate, light compensation and light saturatione0
- Direction
- decreasede0
- Qualifier
- regardless of needle agee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The CO(2) treatment alone increased maximum photosynthetic rate and light-use efficiency, but decreased dark respiration rate, light compensation and light saturation regardless of needle age”
t0“Scots pine”
Claim · model-written summary
Elevated temperature decreased maximum photosynthetic rate and photosynthetic efficiency.
- Taxon
- Scots pinePinus sylvestrist0
- Treatment
- temperature treatmente0
- Outcome
- maximum photosynthetic rate and photosynthetic efficiencye0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the temperature treatment decreased maximum photosynthetic rate and photosynthetic efficiency, but increased dark respiration rate, light compensation and light saturation”
t0“Scots pine”
Claim · model-written summary
Elevated temperature increased dark respiration, light compensation and light saturation.
- Taxon
- Scots pinePinus sylvestrist0
- Treatment
- temperature treatmente0
- Outcome
- dark respiration rate, light compensation and light saturatione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the temperature treatment decreased maximum photosynthetic rate and photosynthetic efficiency, but increased dark respiration rate, light compensation and light saturation”
t0“Scots pine”
Claim · model-written summary
Two-year-old needles had lower values for photosynthetic parameters except photosynthetic efficiency than one-year-old needles.
- Taxon
- Scots pinePinus sylvestrist0
- Organ / stage
- 2- than in 1-year-old needlese0
- Outcome
- values of all parameters except photosynthetic efficiencye0
- Direction
- lesse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“values of all parameters except photosynthetic efficiency were less in 2- than in 1-year-old needles”
t0“Scots pine”
Claim · model-written summary
CO2 treatment decreased the age-associated reduction in maximum photosynthesis.
- Taxon
- Scots pinePinus sylvestrist0
- Treatment
- CO(2) treatmente0
- Outcome
- reduction in maximum photosynthesis due to needle aginge0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The CO(2) treatment decreased and the temperature treatment enhanced the reduction in maximum photosynthesis due to needle aging”
t0“Scots pine”
Claim · model-written summary
Temperature treatment enhanced the age-associated reduction in maximum photosynthesis.
- Taxon
- Scots pinePinus sylvestrist0
- Treatment
- temperature treatmente0
- Outcome
- reduction in maximum photosynthesis due to needle aginge0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The CO(2) treatment decreased and the temperature treatment enhanced the reduction in maximum photosynthesis due to needle aging”
t0“Scots pine”
The same questions in other papers
co2 · physiology: photosynthesis · Pinus sylvestris (Scots pine)Positive and negative results
5 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- positive
4 papers more in this group
See all 8 papers →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.