Increased carbon dioxide levels in air restrict plants' ability to absorb nutrients

June 12, 2015, University of Gothenburg
Increased carbon dioxide levels in air restrict plants’ ability to absorb nutrients
Rice In Japan. Credit: Kazuhiko Kobayashi

The rapidly rising levels of carbon dioxide in the atmosphere affect plants' absorption of nitrogen, which is the nutrient that restricts crop growth in most terrestrial ecosystems. Researchers at the University of Gothenburg have now revealed that the concentration of nitrogen in plants' tissue is lower in air with high levels of carbon dioxide, regardless of whether or not the plants' growth is stimulated. The study has been published in the journal Global Change Biology.

Researcher Johan Uddling has been working with Swedish and international colleagues to compile data on how raised levels of carbon dioxide impact on plant growth and nitrogen absorption.

Plant quality impaired by increased carbon dioxide levels

The study examines various types of ecosystems, including crops, grasslands and forests, and involves large-scale field experiments conducted in eight countries on four continents.

"The findings of the study are unequivocal. The in the crops is reduced in atmospheres with raised carbon dioxide levels in all three ecosystem types. Furthermore, we can see that this negative effect exists regardless of whether or not the plants' growth increases, and even if fertiliser is added. This is unexpected and new," says Johan Uddling, senior lecturer at the Department of Biological and Environmental Sciences at the University of Gothenburg.

Significance of food quality, biodiversity and productivity

When carbon dioxide levels in the air increase, crops in future will have a reduced nitrogen content, and therefore reduced protein levels. The study found this for both wheat and rice, the two most important crops globally. The study also reveals that the strength of the effect varies in different species of grassland, which may impact on the species composition of these ecosystems.

"For all types of ecosystem the results show that high carbon dioxide levels can impede plants' ability to absorb nitrogen, and that this negative effect is partly why raised carbon dioxide has a marginal or non-existent effect on growth in many ecosystems," says Johan Uddling.

Accepted "truths" do not hold

Pine forest in North Carolina. Credit: Will Owens

Reduced nitrogen content in atmospheres with raised has previously been attributed to a kind of dilutive effect, in which nitrogen absorption fails to keep pace with the increase in plants' photosynthesis and growth.

"The findings of this study show that this interpretation is simplified and partly incorrect. We are seeing reduced nitrogen content even when growth has not been affected. Moreover, the effect is there in trials with powerful fertiliser, which indicates that it is not down to limited access to nitrogen in the soil. Future studies should look at what is causing the effect, but it appears to be linked to plants' capacity to absorb rather than to changed levels in the soil," says Johan Uddling.

Grasslands in Minnesota. Credit: Cedar Creek Ecosystem Science Reserve

Explore further: Poorer quality wheat when carbon dioxide levels in the air rise

More information: "Constraints to nitrogen acquisition of terrestrial plants under elevated CO2." Global Change Biology. doi: 10.1111/gcb.12938

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15 comments

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gkam
2.5 / 5 (8) Jun 12, 2015
So much for the arguments of the Ignorati that plants will thrive as we die.

We will ALL die.

That is what we get for politicizing science. The goobers who fell for it are responsible for our fate.
SamB
3.7 / 5 (6) Jun 12, 2015
This is strange since during the Cretaceous period (and others as well) where the carbon dioxide levels were 10 times what they are now, there was a tremendous boom in both plants and animals. http://www.enchan...us.shtml
So why are the plants suffering with such a minor rise in carbon dioxide levels?
gkam
2.7 / 5 (7) Jun 12, 2015
Different plants.

Different animals.

How would you like to live back then?
gkam
3 / 5 (6) Jun 12, 2015
Enchanted Learning is a site for kids. While good, it is not a valid reference for the issue at hand.
TheGhostofOtto1923
4.4 / 5 (7) Jun 12, 2015
This is strange since during the Cretaceous period (and others as well) where the carbon dioxide levels were 10 times what they are now, there was a tremendous boom in both plants and animals. http://www.enchan...us.shtml
So why are the plants suffering with such a minor rise in carbon dioxide levels?


It became interesting. Where you have this information?
Ahaahaaaaa clicking on links is against rens religion I guess.
WillieWard
1.7 / 5 (6) Jun 12, 2015
The rapidly rising levels of carbon dioxide in the atmosphere affect plants' absorption of nitrogen, which is the nutrient that restricts crop growth in most terrestrial ecosystems.
By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Carbon dioxide is well mixed in the Earth's atmosphere and reconstructions show that concentrations of CO2 in the atmosphere have varied, ranging from as high as 7,000 parts per million during the Cambrian period about 500 million years ago to as low as 180 parts per million during the Quaternary glaciation of the last two million years.
"True Fact: The Lack of Pirates Is Causing Global Warming"
http://www.forbes...warming/
gkam
2.3 / 5 (3) Jun 13, 2015
Where have all the Deniers gone?
runrig
5 / 5 (4) Jun 13, 2015
Earth's atmosphere and reconstructions show that concentrations of CO2 in the atmosphere have varied, ranging from as high as 7,000 parts per million during the Cambrian period about 500 million years ago to as low as 180 parts per million during the Quaternary glaciation of the last two million years.


Correct - however CO2 is NOT the only variable.
Around 500m yrs ago the Sun's output was ~4% (54W/m2) less.
Bear in mid that the difference between a glacial and interglacial in recent Earth history has been around 7W/m2.
So the GHE was balancing the weaker TSI.
Other factors:
Albedo.
Continental configuration (very little land in NH).
Orbital configuration.
In short a totally different planet, and not comparable with the today's Earth in any way.

http://www.skepti...iate.htm
http://www.ucmp.b...ect.html
https://en.wikipe..._paradox
Returners
2 / 5 (4) Jun 14, 2015
Of course we know that headline can't be universally true, because the majority of time recorded by the fossil record involves plants thriving in conditions of 2 to 4 times present CO2 levels, and powering enough oxygen and sugar/starch production to fuel the largest land animals to ever live, and some of the largest aquatic animals to ever live.

When carbon dioxide levels in the air increase, crops in future will have a reduced nitrogen content, and therefore reduced protein levels.


Near as I can tell, as significant amount of nitrogen taken up by organisms is actually not used, and passes as one form or another of waste. Amino acid has one nitrogen atom in the entire molecule, while the remainder of the molecule is Carbon, Oxygen, Hydrogen, and one trace element atom, sulfur for example, completing the group and giving it's specific name.

Fossil plants powered the most powerful organisms to ever live, and did so under extreme CO2 levels.
Returners
2 / 5 (4) Jun 14, 2015
There is a canadian energy company which also grows tomatoes in greenhouses adjacent to their power plant. They pump the smoke exhaust from the power facility into the greenhouses, because the tomatoes grow faster and larger in the presence of the ridiculously increased carbon dioxide levels and increased temperatures. The CO2 levels at the point of exhaust are literally toxic to humans, much higher than the natural levels in the environment have been for billions of years, and the tomatoes love it.

Now why does this work if the increased CO2 is bad for plants?!

SteveS
5 / 5 (4) Jun 14, 2015
Amino acid has one nitrogen atom in the entire molecule


Wrong

https://www.neb.c...ructures
RealityCheck
3.7 / 5 (3) Jun 15, 2015
Hi Willie.
ranging from as high as 7,000 parts per million during the Cambrian period about 500 million years ago to as low as 180 parts per million during the Quaternary glaciation of the last two million years.
If I recall correctly, there was no plant life as such during Cambrian. Only sea life from Oxygen-producing producing to the fast diversifying/evolving animals feeding on them by filtration of water/sediment and breathing the Oxygen produced by the bacteria.
RealityCheck
3.7 / 5 (3) Jun 15, 2015
HI Returners.

Note that it is the 'protein value' which is being adversely affected. The nutrient value of a single crop is part of a whole range of dietary foods. So if one depended on 'protein content' of Tomatoes, they would not get sufficient. The example of your 'monoculture' specialist crop growing in higher CO2/heat is not unusual, as it is 'optimized' for Tomatoes which are NOT a 'protein source' crop, merely vitamin/mineral etc as part of a wider diet. The same conditions would be disastrous for a total environment/ecosystem if the protein-producing/dependent aspects were adversely affected.

That was what this study addressed, the 'protein content' aspect, not the general conditions for growth or not. And growth with reduced nutrient value is not good for all animals/health/survivability.
antigoracle
2 / 5 (4) Jun 15, 2015
More conjecture from the AGW Cult for the hungry ignorant AGW Chicken Littles. In higher CO2 plants are more efficient with resources.
http://www.annual...rplant.2
Vietvet
3 / 5 (2) Jun 16, 2015
More conjecture from the AGW Cult for the hungry ignorant AGW Chicken Littles. In higher CO2 plants are more efficient with resources.
http://www.annual...rplant.2


From the abstract: "reduced nutrient quality for insect and animal grazers are all possibilities that have been observed in field studies of the effects of elevated Ca."

"High CO2 levels significantly reduces essential nutrients in wheat, rice, maize and soyabeans, Nature paper reveals"
http://www.thegua...utrition
http://guardianlv...d-crops/

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