Rising carbon dioxide in atmosphere also speeds carbon loss from forest soils: study

Jul 10, 2012

Elevated levels of atmospheric carbon dioxide accelerate carbon cycling and soil carbon loss in forests, new research led by an Indiana University biologist has found.

The new evidence supports an emerging view that although forests remove a substantial amount of carbon dioxide from the atmosphere, much of the carbon is being stored in living rather than as dead organic matter in soils.

Richard P. Phillips, lead author on the paper and an assistant professor of biology in the IU College of Arts and Sciences, said that after nearly two decades of research on forest ecosystem responses to global change, some of the uncertainty has been lifted about how forests are storing carbon in the wake of rising carbon dioxide levels.

"It's been suggested that as trees take up more carbon dioxide from the atmosphere, a greater amount of carbon will go to roots and fungi to acquire nutrients, but our results show that little of this carbon accumulates in soil because the decomposition of root and fungal detritus is also increased," he said.

Carbon stored in soils, as opposed to in the wood of trees, is desirable from a management perspective in that soils are more stable over time, so carbon can be locked away for hundreds to thousands of years and not contribute to increases.

The research was conducted at the Duke Forest Free Air Carbon Dioxide Enrichment site in North Carolina. At this site, mature loblolly pine trees were exposed to increased levels of carbon dioxide for 14 years, making it one of the longest-running enrichment experiments in the world. Researchers were able to calculate the age of the carbon cycling through the soil by growing roots and into mesh bags that contained uniquely labeled soils. The soils were then analyzed for their organic composition.

The authors also report that nitrogen cycled faster in this forest as the demand for nutrients by trees and microbes became greater under elevated CO2.

"The growth of trees is limited by the availability of nitrogen at this site, so it makes sense that trees are using the 'extra' carbon taken up under elevated CO2 to prime microbes to release nitrogen bound up in organic matter," Phillips said. "What is surprising is that the trees seem to be getting much of their nitrogen by decomposing root and fungal detritus that is less than a year old."

The two-fold effects of microbial priming, where microbes are stimulated to decompose old soil via an increase in new carbon and other energy sources, and the faster turnover of recently fixed root and fungal carbon, are enough to explain the rapid carbon and nitrogen cycling that is occurring at the Duke Forest FACE site.

"We call it the RAMP hypothesis -- Rhizo-Accelerated Mineralization and Priming -- and it states that root-induced changes in the rates of microbial processing of carbon and nitrogen are key mediators of long-term ecosystem responses to ," Phillips added.

"Most ecosystem models have limited representations of roots, and none of them include processes such as priming. Our results demonstrate that interactions between roots and soil microbes play an underappreciated role in determining how much carbon is stored and how fast nitrogen is cycled. So including these processes in models should lead to improved projections of long-term carbon storage in forests in response to global environmental change'" he said.

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More information: "Roots and fungi accelerate carbon and nitrogen cycling in forests exposed to elevated CO2" -- by Phillips; IU and University of Gottingen (Germany) post-doctoral researcher Ina C. Meier; Emily S. Bernhardt of Duke University, A. Stuart Grandy and Kyle Wickings of the University of New Hampshire; and Adrien C. Finzi of Boston University -- was published July 9 in the online early addition of Ecology Letters. Free access to the research article will be available until October.

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Vendicar_Decarian
3.4 / 5 (10) Jul 10, 2012
More bad news for the denialists.

It is another bad day for them in a bad month for them, in a bad year for them.

Warmest 12 months in recorded history.

Oh wait. ParkerTard is still claiming that the earth is cooling.

Ignorant filth.
NotParker
1.8 / 5 (10) Jul 10, 2012
IPCC trees bad.

IPCC trees good.

Alternate every couple of weeks.
ZachAdams
4.7 / 5 (7) Jul 10, 2012
NotParker I'm assuming that you aren't convinced by the research that CO2 is the cause of global warming, or that global warming even exists.

What do you stand to gain from your position?

In fifty years do you just want to be able to say "See I was right?"

What do you see as the negatives that would be caused by an effort for CO2 reduction?

I'm not into name calling and I would really like to understand your rationale.
rubberman
4.1 / 5 (9) Jul 10, 2012
NotParker I'm assuming that you aren't convinced by the research that CO2 is the cause of global warming, or that global warming even exists.

What do you stand to gain from your position?

In fifty years do you just want to be able to say "See I was right?"

What do you see as the negatives that would be caused by an effort for CO2 reduction?

I'm not into name calling and I would really like to understand your rationale.


In the event you do engage in enough debate time with Parker, you will also resort to name calling...or you will just lose patience and not acknowledge "it". I bounce between the two...depending on the topic and the absurdity of what it says.
ZachAdams
4.3 / 5 (7) Jul 10, 2012
Not really. But I am really curious as to why those who deny global warming see it as such a personal issue. It seems to me that the politicians have polarized the issue as a way of cleaving political opinion in order to protect their voting constituency.

What I want to know is what the 'denialists' think they have to lose. Why can't argue that point in public for all to see.

Who holds the purse strings on this?
djr
5 / 5 (6) Jul 10, 2012
David - trees good.

David - trees good.

This article - trees good - but they don't bind as much carbon as we may have previously thought - but none the less - trees good. I like science - it continually increases our knowledge of the natural world.
NotParker
2 / 5 (8) Jul 10, 2012
What do you see as the negatives that would be caused by an effort for CO2 reduction?


Unnecessary skyrocketing energy bills for the old and poor and middle class for one.

http://thegwpf.or...ies.html

"The isolated energy policy of the German government will cost Germans 2.3 trillion . In numbers thats 2,300,000,000,000. And for what? To brake a computer-simulated increase in global temperature a whole 0.003 °C."

http://notrickszo...0-003°c/
Vendicar_Decarian
3.9 / 5 (7) Jul 11, 2012
ParkerTard posts more nonsense from a Denialist blog "no tricks zone"

It's all science free of course.
NotParker
1.8 / 5 (5) Jul 11, 2012
ParkerTard posts more nonsense from a Denialist blog "no tricks zone"

It's all science free of course.


The article in question is economics.

Trillions of dollars to be spent, lowering the cost of living for many germans, and all for nothing.

Switching to shale gas would accomplish much, much more and save Germany money.

Fanatics like VD and the AGW want to punish the poor and elderly and middle class.
Howhot
2.3 / 5 (3) Jul 12, 2012
Fanatics like VD and the AGW want to punish the poor and elderly and middle class.


So Noparks (he hates parks), your debate tactics are shriveling up. Did you have a hard day?
ubavontuba
2.6 / 5 (5) Jul 12, 2012
The research was conducted at the Duke Forest Free Air Carbon Dioxide Enrichment site in North Carolina.
So an experiment performed at in one test forest in North Carolina translates to all forests, everywhere? Hardly. Decomposition is significantly retarded in boreal forests.
NotParker
2.3 / 5 (3) Jul 12, 2012
Fanatics like VD and the AGW want to punish the poor and elderly and middle class.


So Noparks (he hates parks), your debate tactics are shriveling up. Did you have a hard day?


The Spanish have the right idea.

Tax renewables.

With subsidies shrinking it will help kill off the evil renewables con game.

http://www.busine...ergy-tax
Howhot
3 / 5 (2) Jul 12, 2012
Tax renewables.

Amazing, I can't believe Noparks actually supports taxes! Holly cow! What will R2 think?!?! Kidding of course. I'm being off topic.

From the article;
Rhizo-Accelerated Mineralization and Priming
seem like an interesting observation. Added CO2 leads to a more rapid uptake of nitrogen and less CO2 sequestered in the soil.
NotParker
2.3 / 5 (3) Jul 12, 2012
Tax renewables.

Amazing, I can't believe Noparks actually supports taxes!


Taxing stupidity is a good thing. Subsidies for renewables are stupid.
Howhot
2.3 / 5 (3) Jul 12, 2012
Actually Subsidies for renewables is a great idea! Again, your on the wrong side of something that would benefit man by reducing fossil fuel emissions.