Abstract
ABSTRACT Small birch plants were grown for up to 80 d in a climate chamber at varied relative addition rates of nitrogen in culture solution, and at ambient (350 μmol mol ‐1 ) or elevated (700 μmol mol ‐1 ) concentrations of CO 2 . The relative addition rate of nitrogen controlled relative growth rate accurately and independently of CO 2 concentration at sub‐optimum levels. During free access to nutrients, relative growth rate was higher at elevated CO 2 . Higher values of relative growth rate and net assimilation rate were associated with higher values of plant N‐concentration. At all N‐supply rates, elevated CO 2 resulted in higher values of net assimilation rate, whereas leaf weight ratio was independent of CO 2 . Specific leaf area (and leaf area ratio) was less at higher CO 2 and at lower rates of N‐supply. Lower values of specific leaf area were partly because of starch accumulation. Nitrogen productivity (growth rate per unit plant nitrogen) was higher at elevated CO 2 . At sub‐optimal N‐supply, the higher net assimilation rate at elevated CO 2 was offset by a lower leaf area ratio. Carbon dioxide did not affect root/shoot ratio, but a higher fraction of plant dry weight was found in roots at lower N‐supply. In the treatment with lowest N‐supply, five times as much root length was produced per amount of plant nitrogen in comparison with optimum plants. The specific fine root length at all N‐supplies was greater at elevated CO 2 . These responses of the root system to lower N‐supply and elevated CO 2 may have a considerable bearing on the acquisition of nutrients in depleted soils at elevated CO 2 . The advantage of maintaining steady‐state nutrition in small plants while investigating the effects of elevated CO 2 on growth is emphasized.
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Claims 13
Claim · model-written summary
Relative growth rate was higher at elevated CO2 when nutrients were freely available.
- Taxon
- Betula pendula
Betula pendulat0 - Treatment
- elevated CO 2e1
- Outcome
- relative growth ratee1
- Direction
- highere1
- Qualifier
- During free access to nutrientse1
- Comparator
- ambiente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“and at ambient (350 μmol mol ‐1 ) or elevated (700 μmol mol ‐1 ) concentrations of CO 2”
e1“During free access to nutrients, relative growth rate was higher at elevated CO 2”
Claim · model-written summary
Net assimilation rate was higher at elevated CO2 at all nitrogen supply rates.
- Taxon
- Betula pendulaBetula pendulat0
- Treatment
- elevated CO 2e1
- Outcome
- net assimilation ratee1
- Direction
- higher valuese1
- Comparator
- ambiente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“and at ambient (350 μmol mol ‐1 ) or elevated (700 μmol mol ‐1 ) concentrations of CO 2”
e1“At all N‐supply rates, elevated CO 2 resulted in higher values of net assimilation rate”
Claim · model-written summary
Higher relative growth rate and net assimilation rate were associated with higher plant N concentration.
- Taxon
- Betula pendulaBetula pendulat0
- Compound
- Ne0
- Outcome
- relative growth rate and net assimilation ratee0
- Direction
- higher valuese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“Higher values of relative growth rate and net assimilation rate were associated with higher values of plant N‐concentration”
Claim · model-written summary
Specific leaf area was lower at higher CO2 and at lower nitrogen supply.
- Taxon
- Betula pendulaBetula pendulat0
- Treatment
- higher CO 2e0
- Outcome
- Specific leaf areae0
- Direction
- lesse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“Specific leaf area (and leaf area ratio) was less at higher CO 2 and at lower rates of N‐supply”
Claim · model-written summary
Lower specific leaf area was partly caused by starch accumulation.
- Taxon
- Betula pendulaBetula pendulat0
- Outcome
- Lower values of specific leaf areae0
- Qualifier
- partly because of starch accumulatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“Lower values of specific leaf area were partly because of starch accumulation”
Claim · model-written summary
Nitrogen productivity was higher at elevated CO2.
- Taxon
- Betula pendulaBetula pendulat0
- Treatment
- elevated CO 2e1
- Outcome
- Nitrogen productivity (growth rate per unit plant nitrogen)e1
- Direction
- highere1
- Comparator
- ambiente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“and at ambient (350 μmol mol ‐1 ) or elevated (700 μmol mol ‐1 ) concentrations of CO 2”
e1“Nitrogen productivity (growth rate per unit plant nitrogen) was higher at elevated CO 2”
Claim · model-written summary
Carbon dioxide did not change the root/shoot ratio.
- Taxon
- Betula pendulaBetula pendulat0
- Treatment
- Carbon dioxidee0
- Outcome
- root/shoot ratioe0
- Direction
- no_changeinferrede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“Carbon dioxide did not affect root/shoot ratio, but a higher fraction of plant dry weight was found in roots at lower N‐supply”
Claim · model-written summary
A higher fraction of plant dry weight was found in roots at lower nitrogen supply.
- Taxon
- Betula pendulaBetula pendulat0
- Organ / stage
- rootse0
- Treatment
- lower Ne0
- Outcome
- fraction of plant dry weighte0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“Carbon dioxide did not affect root/shoot ratio, but a higher fraction of plant dry weight was found in roots at lower N‐supply”
Claim · model-written summary
Under the lowest nitrogen supply, five times as much root length was produced per amount of plant nitrogen than in optimum plants.
- Taxon
- Betula pendulaBetula pendulat0
- Treatment
- lowest Ne0
- Outcome
- root lengthe0
- Direction
- higherinferrede0
- Value
- five times as muche0
- Comparator
- optimum plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“In the treatment with lowest N‐supply, five times as much root length was produced per amount of plant nitrogen in comparison with optimum plants”
Claim · model-written summary
Specific fine root length was greater at elevated CO2 at all nitrogen supply rates.
- Taxon
- Betula pendulaBetula pendulat0
- Treatment
- elevated CO 2e1
- Outcome
- specific fine root lengthe1
- Direction
- greatere1
- Comparator
- ambiente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“and at ambient (350 μmol mol ‐1 ) or elevated (700 μmol mol ‐1 ) concentrations of CO 2”
e1“The specific fine root length at all N‐supplies was greater at elevated CO 2”
Claim · model-written summary
At sub-optimal nitrogen supply, the higher net assimilation rate at elevated CO2 was offset by a lower leaf area ratio.
- Taxon
- Betula pendulaBetula pendulat0
- Treatment
- elevated CO 2e1
- Outcome
- leaf area ratioe1
- Direction
- lowere1
- Comparator
- ambiente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“and at ambient (350 μmol mol ‐1 ) or elevated (700 μmol mol ‐1 ) concentrations of CO 2”
e1“At sub‐optimal N‐supply, the higher net assimilation rate at elevated CO 2 was offset by a lower leaf area ratio”
Claim · model-written summary
Leaf weight ratio was independent of CO2.
- Taxon
- Betula pendulaBetula pendulat0
- Treatment
- CO 2e0
- Outcome
- leaf weight ratioe0
- Direction
- no_changeinferrede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“At all N‐supply rates, elevated CO 2 resulted in higher values of net assimilation rate, whereas leaf weight ratio was independent of CO 2”
Claim · model-written summary
The relative addition rate of nitrogen controlled relative growth rate at sub-optimal levels, independent of CO2 concentration.
- Taxon
- Betula pendulaBetula pendulat0
- Treatment
- relative addition rate of nitrogene0
- Outcome
- relative growth ratee0
- Qualifier
- accurately and independently of CO2 concentratione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Response of small birch plants (Betula pendula Roth.) to elevated CO2 and nitrogen supply”
e0“The relative addition rate of nitrogen controlled relative growth rate accurately and independently of CO2 concentration at sub‐optimum levels”
The same questions in other papers
co2 · growth · Betula pendula (white birch)Positive and negative results
3 papers in the same direction as this paper · 1 in the opposite direction · 1 reporting no difference from an alternative
- no effect
- no effect
- positive
2 papers more in this group
See all 6 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.