Nitrogen study casts doubt on ability of plants to continue absorbing same amounts of CO2

October 23, 2018

A new study casts doubt as to whether plants will continue to absorb as much carbon dioxide in the future as they have in the past due to declining availability of nitrogen in certain parts of the world.

When it comes to the role plants play in keeping the heat-trapping greenhouse gas out of the atmosphere, "it may not be business as usual," said Lixin Wang, an associate professor in the Department of Earth Sciences at IUPUI.

Wang is a co-author of the paper "Isotopic evidence for oligotrophication of terrestrial ecosystems," which reports that finding. It was published Oct. 22 in the journal Nature Ecology and Evolution.

Grasslands View print quality image

In grasslands and forests, which are not directly fertilized, the availability of nitrogen to plants is declining. The study examines global availability of nitrogen, using a data set that is more than 30,000 data points larger than those previously used to determine nitrogen availability.

An essential nutrient for plants as well as for humans and animals, nitrogen is used widely in more urban, developed countries to fertilize crops. In fact, it has been used so widely that its use has raised serious environmental concerns.

That gave people the impression "that we are kind of nitrogen-saturated everywhere, that we have too much nitrogen," Wang said.

But the researchers found that perception is not true.

In natural systems such as grasslands and forests that are not directly fertilized, the researchers said, the availability of nitrogen to plants is declining. As availability declines, compared to the relative demand for the nutrient due to plants leafing out earlier and the longer growing seasons associated with climate warming, plants are suffering from nitrogen deficiency, Wang said.

"In such systems, which cover a large part of the world, demand for nitrogen is rising at a faster rate than the supply of nitrogen," Wang said.

With nitrogen deficiency, plants are unable to absorb the same quantity of carbon dioxide as they did previously.

"We know that plants reliably suck up carbon dioxide that we emit into the environment," Wang said. "But the problem right now is if plants are suffering more and more nitrogen limitations, it means they will be able to take up less and less of the extra carbon dioxide."

"Not only will plants be more stressed for nitrogen," said Joseph Craine, the paper's lead author, "but so will animals that eat plants. Less nitrogen in plants means less protein for herbivores, which could threaten the entire food chain."
-end-


Indiana University

Related Nitrogen Articles from Brightsurf:

Chemistry: How nitrogen is transferred by a catalyst
Catalysts with a metal-nitrogen bond can transfer nitrogen to organic molecules.

Illinois research links soil nitrogen levels to corn yield and nitrogen losses
What exactly is the relationship between soil nitrogen, corn yield, and nitrogen loss?

Reducing nitrogen with boron and beer
The industrial conversion of nitrogen to ammonium provides fertiliser for agriculture.

New nitrogen products are in the air
A nifty move with nitrogen has brought the world one step closer to creating a range of useful products -- from dyes to pharmaceuticals -- out of thin air.

'Black nitrogen'
In the periodic table of elements there is one golden rule for carbon, oxygen, and other light elements.

A deep dive into better understanding nitrogen impacts
This special issue presents a selection of 13 papers that advance our understanding of cascading consequences of reactive nitrogen species along their emission, transport, deposition, and the impacts in the atmosphere.

How does an increase in nitrogen application affect grasslands?
The 'PaNDiv' experiment, established by researchers of the University of Bern on a 3000 m2 field site, is the largest biodiversity-ecosystem functioning experiment in Switzerland and aims to better understand how increases in nitrogen affect grasslands.

Reducing reliance on nitrogen fertilizers with biological nitrogen fixation
Crop yields have increased substantially over the past decades, occurring alongside the increasing use of nitrogen fertilizer.

Flushing nitrogen from seawater-based toilets
With about half the world's population living close to the coast, using seawater to flush toilets could be possible with a salt-tolerant bacterium.

We must wake up to devastating impact of nitrogen, say scientists
More than 150 top international scientists are calling on the world to take urgent action on nitrogen pollution, to tackle the widespread harm it is causing to humans, wildlife and the planet.

Read More: Nitrogen News and Nitrogen Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.