High CO2 boosts plant respiration, potentially affecting climate and crops

Here’s something you don’t see everyday: a university sending out a press release showing the potential benefits on crop yields of elevated atmospheric CO2 levels. – Anthony

Public release date: 9-Feb-2009

http://www.eurekalert.org/pub_releases/2009-02/uoia-hcb020609.php

Contact: Diana Yates

diya@illinois.edu

217-333-5802

University of Illinois at Urbana-Champaign

High CO2 boosts plant respiration, potentially affecting climate and crops

The leaves of soybeans grown at the elevated carbon dioxide (CO2) levels predicted for the year 2050 respire more than those grown under current atmospheric conditions, researchers report, a finding that will help fine-tune climate models and could point to increased crop yields as CO2 levels rise. The study, from researchers at the University of Illinois and the U.S. Dept. of Agriculture, appears this week in the Proceedings of the National Academy of Sciences. Plants draw CO2 from the atmosphere and make sugars through the process of photosynthesis. But they also release some CO2 during respiration as they use the sugars to generate energy for self-maintenance and growth. How elevated CO2 affects plant respiration will therefore influence future food supplies and the extent to which plants can capture CO2 from the air and store it as carbon in their tissues. While there is broad agreement that higher atmospheric CO2 levels stimulate photosynthesis in C3 plants, such as soybean, no such consensus exists on how rising CO2 levels will affect plant respiration.

IMAGE: Andrew Leakey and assistants at work in the Soy FACE facility at Illinois. Click here for more information.

“There’s been a great deal of controversy about how plant respiration responds to elevated CO2,” said U. of I. plant biology professor Andrew Leakey, who led the study. “Some summary studies suggest it will go down by 18 percent, some suggest it won’t change, and some suggest it will increase as much as 11 percent.” Understanding how the respiratory pathway responds when plants are grown at elevated CO2 is key to reducing this uncertainty, Leakey said.

His team used microarrays, a genomic tool that can detect changes in the activity of thousands of genes at a time, to learn which genes in the high CO2 plants were being switched on at higher or lower levels than those of the soybeans grown at current CO2 levels. Rather than assessing plants grown in chambers in a greenhouse, as most studies have done, Leakey’s team made use of the Soybean Free Air Concentration Enrichment (Soy FACE) facility at Illinois. This open-air research lab can expose a soybean field to a variety of atmospheric CO2 levels – without isolating the plants from other environmental influences, such as rainfall, sunlight and insects. Some of the plants were exposed to atmospheric CO2 levels of 550 parts per million (ppm), the level predicted for the year 2050 if current trends continue. These were compared to plants grown at ambient CO2 levels (380 ppm).

The results were striking. At least 90 different genes coding the majority of enzymes in the cascade of chemical reactions that govern respiration were switched on (expressed) at higher levels in the soybeans grown at high CO2 levels. This explained how the plants were able to use the increased supply of sugars from stimulated photosynthesis under high CO2 conditions to produce energy, Leakey said. The rate of respiration increased 37 percent at the elevated CO2 levels. The enhanced respiration is likely to support greater transport of sugars from leaves to other growing parts of the plant, including the seeds, Leakey said. “The expression of over 600 genes was altered by elevated CO2 in total, which will help us to understand how the response is regulated and also hopefully produce crops that will perform better in the future,” he said.

IMAGE: Illinois plant biology professor Andrew Leakey led a team that discovered that soybean leaves speed up their metabolism in response to rising CO2. Click here for more information.

###

Get notified when a new post is published.
Subscribe today!
0 0 votes
Article Rating
226 Comments
Inline Feedbacks
View all comments
E.M.Smith
Editor
February 11, 2009 2:00 am

Gary Hladik (11:20:35) :
James P (04:08:00) : “I take your general point, but IIRC, about a third of the world goes to bed hungry.”
According to the UN Food and Agriculture organization, the proportion of world population “undernourished” was about 16%

The difference is the 17% that go to bed hungry because they are on a diet trying to lose weight…

E.M.Smith
Editor
February 11, 2009 2:45 am

Philip_B (22:22:42) : Pamela, every gene and every capability expressed from a gene has a cost (you can think of cost as finding food to fuel it). Natural selection over time will select those genes and capabilities that deliver the most value for the least cost and lose all other genes and their expressions.
Is that why I still have an appendix (that is functional in the rabbit but not so much in primates…) after all these years not being a rabbit?

Mary Hinge
February 11, 2009 6:14 am

E.M.Smith (01:20:03) :
CO2 is clearly a ‘rate limiting nutrient’. As such, any increase will result in increased plant growth. It ought to be ‘concentration proportional’ up to the full utilization level. Elsewhere I’ve seen this reported as about 1000 to 2000 ppm.

Increased CO2 can only increase plant growth if the plant has extra water, nitrogen and trace elements to support this extra growth. Availability of water throughout the growing season seems to be a problem in many parts of the world. Rapid climate shifts and increasing temperature extremes as predicted by AGW would increase this problem and more than negate any benifits of extra co2.

This, IMHO, is clear evidence that most life on this planet evolved to expect 1000ppm+ and has had it for most of evolutionary history (and would want it again…)<blockquote
If this was the case why is the recent era (shortly before the presence of Homo sapiens) the most biologically diverse the earth has ever been? As long as changes happen at ‘normal’ speeds then organisms will adapt via evolution by natural selection. Rapid changes in atmospheric constituents have previously resulted in mass extinctions and recovery times for biodiversity of millions of years.

That, to me, is the strongest possible argument that added CO2 is a very good thing…

Then your ‘strongest possible argument’ is extremely flawed, you might want to take another look.

Pamela Gray
February 11, 2009 7:00 am

Animals that live past productive life tend to be in herding or social group species. The wisdom of age and the ability to fend off threats without having to stay near offspring is advantageous to the survival of herds and social groups. There are probably plants that do this same thing, by possibly keeping the area physically crowded or surrounded with its own reproducing species so that competing plants can’t move in.
However, there are still lots and lots of genetic code, expressed as traits or long silenced, that are just there, and continue on, riding on the coattails of genes nearby that improve species survival in the current environment. Gene coding is a chaotic system for most of it, and a selective process for some of it.

Terry Ward
February 11, 2009 8:10 am

E.M.Smith (22:50:08) :
“Terry Ward (01:41:28) : It is just about useful for animal feed, but if I ruled the world it wouldn’t even be allowed for that purpose.
Curious… Why? Isn’t a plant just a plant? Near 50% oil and most of the rest protein that’s a great animal food…”
Rather than rant about it I offer one of the best soy debunk sites;
http://www.soyonlineservice.co.nz/

February 11, 2009 10:22 am

Breaking News: Trees Love Greenhouse Gas
They can’t get enough of it, in fact they need it to survive and grow. The more CO2 there is the more they convert it into Oxygen for us to breath. It’s a beautiful symbiotic realtionship between man and plants called Photosynthesis.
In 2003 scientist set out to prove the effect of greenouse gasses on trees. They planted trees in New York City and trees way out in the woods. To their suprise, the trees planted in the city grew twice as rapidly as the ones in the country.
link to article.

“In the country, the trees were about up to my waist. In the city, they were almost over my head — it’s really dramatic,” said Jillian W. Gregg, the study’s lead author.

“No matter what soil I grew them in they always grew twice as large in New York City,” said Gregg, who said she was initially perplexed by the unexpected results.

Full Article

Mark Stewart
February 11, 2009 12:22 pm

I wonder if marine crustaceans have similar relic genes that switch on in reponse to recreation of ancient local conditions. I believe the fossil record shows crustaceans evolved or lived through periods with higher pH, CO2, and temperatures- even thrived. If such a genetic reponse was observed, manmade CO2 driven ocean acidification may not be so dire either.

Fernando
February 11, 2009 1:26 pm

Interesting genes, apparently are very sensitive
I return to the matter: “we” like to talk about
A Mathematical Model for Mass Extinction:
http://www.lassp.cornell.edu/newmme/science/extinction.html
http://www.lassp.cornell.edu/newmme/science/ModelsOfExtinction.pdf

Syl
February 11, 2009 3:52 pm

Mary Hinge
You missed the point that it is not necessary to wait for evolutionary changes for plants to adapt. It’s already built in. As is the ability for humans to choose what to plant where and when. Scaremongering by use of model output that is based on unproven assumptions was a nice tactic that is rapidly losing its persuasive power.

Pamela Gray
February 11, 2009 7:48 pm

Just wanted to give one last parting shot regarding the mess we call genes. Hansen’s code looks positively obsessively compulsively ordered compared to DNA coding. This is a quick and layman-like read on the utter chaos some people think is ordered. And yes, the author is right. We have lots and lots of junk DNA. It’s never used. It serves no function. And our own bodies know it because it cuts and pastes around the junk segments. Could the junk segments be the result of constant mutations of once used but now useless genes? So, they don’t die. They just get confused.
http://psych.colorado.edu/~carey/hgss/hgsschapters/HGSS_Chapter03.pdf
REPLY: Maybe the secret to conquering aging is to take out the trash. – Anthony

Pamela Gray
February 11, 2009 8:19 pm

As an analogy, our genetic code operating system never seems to throw out anything it no longer uses. Kind of like the code used between the old MS DOS and windows. The Y2K problem could not be readily fixed because the original code writers were no longer alive to help pinpoint the area of the code that needed to be fixed. Old codes were never thrown out. They were just added onto or patches developed. No one ever (or rarely) when back into the code and actually tried to fix it. And finding all the attached and looped codes that depended on old codes was a nightmare. Which is why patches were devised and then sacrifices made. There was absolutely no assurance that the fixes would work. Apple and McIntosh systems running on OS did not have this problem because the code was of a more recent vintage, thus it was originally written with 2000 in mind (which I believe might have a problem in 2030-something).
Our genes are a lot like the old original computer code that just kept getting added on to without getting rid of the old stuff. In other words, we are pack rats…not to mention piss poor code writers.

Mary Hinge
February 12, 2009 1:35 am

Syl (15:52:35) :
You missed the point that it is not necessary to wait for evolutionary changes for plants to adapt. It’s already built in. As is the ability for humans to choose what to plant where and when.

You, I and every member of the human race has the genes for a prehensile tail ‘built in’. It does’t mean that it will switch on readily (which is good news for tailors)! The ‘switches’ that turn on or off the genes have also evolved so that the organism is adapted to the current conditions. Like the genes for the tail, these will not switch on or off readily so it becomes immaterial that the genes ‘built in’ arestill around somewhere. The plants that were around during the higher CO2 levels of the early Carboniferous are very different to the plants alive today (with the usual odd exception that always happens with biology!)

February 12, 2009 6:11 am

Mary Hinge

Increased CO2 can only increase plant growth if the plant has extra water, nitrogen and trace elements to support this extra growth. Availability of water throughout the growing season seems to be a problem in many parts of the world. Rapid climate shifts and increasing temperature extremes as predicted by AGW would increase this problem and more than negate any benifits of extra co2.

It appears that your belief is that AGW will cause more droughts everywhere, and will cause droughts which will negate any benefits from increased atmospheric CO2.
Since the amount of rainfall is more or less constant globally, that particular scare tactic fails. If one area experiences drought conditions, then another marginal area will get additional rainfall, which will result in better growing conditions in that area if CO2 is abundant.
What will it take for you to understand that “climate change” is composed of changing local weather patterns around the globe? An epiphany?
At some point the scales will fall from your eyes. If not, everyone will realize that your beliefs are based on a politically based AGW agenda, rather than on a desire to understand the true reason for global warming, which is a natural result of the planet’s emergence from the last Ice Age.
Maybe I’m the crazy one, but I think there is hope for you. If rising CO2 levels do not result in rising global temperatures, and if CO2 triggers plant growth, then the conclusion is obvious to even the most casual observer: higher levels of CO2 are beneficial to life. Therefore demonizing CO2 is anti-life.

Mary Hinge
February 12, 2009 9:17 am

Smokey (06:11:15) :
It appears that your belief is that AGW will cause more droughts everywhere, and will cause droughts which will negate any benefits from increased atmospheric CO2.

My actual belief in itself won’t cause an increased probability of droughts in many prime agricultural areas, but the effects of AGW will.

Since the amount of rainfall is more or less constant globally, that particular scare tactic fails. If one area experiences drought conditions, then another marginal area will get additional rainfall, which will result in better growing conditions in that area if CO2 is abundant.

Sorry Smokey but that is a ridiculous statement. If agricultural areas experience drought conditions then that certainly reduces any benefits of additional CO2, especially if the marginal areas consist of mountains, forest or oceans. A small change in rainfall in some areas will undoubtally have major effects either regionally or even globally.

What will it take for you to understand that “climate change” is composed of changing local weather patterns around the globe? An epiphany?

Errr, of course climate change is composed of changing local weather patterns, that’s why it’s called ‘change’. The important factor is the rate of change and how fast we and the rest of life on Earth can adapt to this.

At some point the scales will fall from your eyes. If not, everyone will realize that your beliefs are based on a politically based AGW agenda, rather than on a desire to understand the true reason for global warming, which is a natural result of the planet’s emergence from the last Ice Age.

I do not belong to any political party not do I have any interest in the politics of global warming discussions. I care about this planet and the people and life that inhabits it. It is obvious to anyone that reads the literature and other data we have available that there are major climatic changes happening, it is also obvious that your own theory is flawed in that you haven’t described a particular method nor an explanation for the very rapid rise in the last 100 years.

Maybe I’m the crazy one,

At last a grain of truth from you 😉

….but I think there is hope for you. If rising CO2 levels do not result in rising global temperatures, and if CO2 triggers plant growth, then the conclusion is obvious to even the most casual observer: higher levels of CO2 are beneficial to life. Therefore demonizing CO2 is anti-life.

Lots of ‘ifs’ in that statement. CO2 will/has result(ed) in an increase in global temperatures, try that scale remover yourself!

February 12, 2009 9:32 am

OK, try this ‘if’ on for size:
If the planet warms, evaporation increases.
If evaporation increases, precipitation [rain] increases.
If rain increases, droughts decrease.
Unless, of course, down is up, black is white, evil is good, a warmer climate decreases evaporation, and global warming causes global cooling.

Mary Hinge
February 12, 2009 11:26 am

Smokey (09:32:37) :
OK, try this ‘if’ on for size:
If the planet warms, evaporation increases.
If evaporation increases, precipitation [rain] increases.
If rain increases, droughts decrease.

The problems are not so much the quantity of rain globally but where it does or does not fall. Increased rainfall in areas not accustomed to this as well as decreased rainfall in areas used to it WILL cause problems in food producing regions. You seem to think that rainfall is pretty evenly distributed?

Fernando
February 12, 2009 12:17 pm

Sorry:
Smokey and Mary Hinge
water vapor positive feedback
this is science fiction

Jeff Alberts
February 12, 2009 12:19 pm

Mary Hinge (11:26:24) :
The problems are not so much the quantity of rain globally but where it does or does not fall. Increased rainfall in areas not accustomed to this as well as decreased rainfall in areas used to it WILL cause problems in food producing regions. You seem to think that rainfall is pretty evenly distributed?

Has happened before, will happen again, regardless of whether humans even exist.

max_b
February 12, 2009 12:20 pm

A warmer planet tends to be a wetter planet, a colder planet tends to be drier one from what I’ve read. Weather patterns change as climate changes, see the ‘Greening of the Sahel’ for a nice example.

Mary Hinge
February 13, 2009 6:31 am

Jeff Alberts (12:19:57) :
Has happened before, will happen again, regardless of whether humans even exist.

The big problems occur when these rapid changing events happen when over 6,000,000,000 people live on the planet.

E.M.Smith
Editor
February 13, 2009 3:30 pm

Mary Hinge (06:14:26) : Increased CO2 can only increase plant growth if the plant has extra water, nitrogen and trace elements to support this extra growth. Availability of water throughout the growing season seems to be a problem in many parts of the world.
I can only assume that you are unaware of the studies that showed increased plant growth with higher CO2 despite no increase in water. The plants are more efficient in water use with more CO2. More CO2 mitigates drought issues for plants.
Many sources of nitrogen fixation exist, including plants that fix their own nitrogen. A red herring. Ditto trace elements. Yes, each individual soil may have some element that becomes rate limiting. So what. Most soils most of the time are not rate limited on trace minerals. If you have a problem, add some volcano dust… Trace is just another red herring.
This, IMHO, is clear evidence that most life on this planet evolved to expect 1000ppm+ and has had it for most of evolutionary history (and would want it again…)
If this was the case why is the recent era (shortly before the presence of Homo sapiens) the most biologically diverse the earth has ever been?
A rather bald assertion with nothing to back it up. That’s just a large rat hole to go explore. Does diversity matter? How to determine ‘diversity’? Does the precambrian variety of major body plans outweigh the minor species variations of today? How well does the fossil record record soft bodied critters? What was the impact of the development of sex on the rate of species creation? What is the impact of entering an interglacial on species diversity?
All very interesting questions, and all very irrelevant to this blog. So no, I will not indulge in Rat Chasing; down rat holes or otherwise.
If plants were fully satisfied with their CO2 needs at 200 ppm it would not be rate limiting. If they had had time to fully evolve toward a 200 ppm norm, they would not be rate limited on CO2. The development of C4 metabolism seems to be a partial step in that direction, so plants have been stressed ‘for a while’, but most are still C3 and even C4 is not fully adaptive.
Yes, there is an atmospheric environmental stress on plants, but that stress is too low a CO2 level; as the plants themselves testify by their growth.
BTW, if you are really interested in the problems of drought, perhaps you ought to switch ‘sides’. Drought increases dramatically during ice ages because cold air holds less water than warm air. Warmer air will bring more rains, not less. (Which, unfortunately, is why during this current couple of year cold spell California is having one heck of a drought. Though for the last week my accidental ‘prayer to the rain Gods’ has resulted in some much needed rain…)
Pessimums with poor crop growth are cold. Optimums with good plant growth are warm. Fact of history. Fact of life.
The simple fact is that plants want and need more CO2 to work at full efficiency including the efficiency with which they use water. This holds up to about 1000 to 2000 ppm CO2. That is not an accident, that is the result of directed design via evolution. It’s not gonna change ’cause you don’t like it.
That, to me, is the strongest possible argument that added CO2 is a very good thing…
You might want to take another look.

E.M.Smith
Editor
February 13, 2009 3:42 pm

Pamela Gray (07:00:07) : There are probably plants that do this same thing, by possibly keeping the area physically crowded or surrounded with its own reproducing species so that competing plants can’t move in.
http://en.wikipedia.org/wiki/Allelopathy
Plants make a bunch of ‘chemical weapons’ to kill off intruder species. That’s why the lawn dies under the walnut tree. There is a whole art to ‘companion planting’ to find which plants ignore each others attacks… (Be careful where you plant sunflowers… and don’t plant peas and onions together..)
However, there are still lots and lots of genetic code, expressed as traits or long silenced, that are just there, and continue on, riding on the coattails of genes nearby that improve species survival in the current environment. Gene coding is a chaotic system for most of it, and a selective process for some of it.
Absolutely! My favorite example of this is the experiments that have shown birds still have the genes for teeth. They are just back in the ‘tool chest’ portion and not in the ‘active’ portion…
Transplant ‘gum’ tissue to a different part of the bird embryo and it makes teeth…

E.M.Smith
Editor
February 13, 2009 4:10 pm

Terry Ward (08:10:32) :
E.M.Smith (22:50:08) :”Curious… Why? Isn’t a plant just a plant? Near 50% oil and most of the rest protein that’s a great animal food…”
Rather than rant about it I offer one of the best soy debunk sites;
http://www.soyonlineservice.co.nz/

First, I have to correct my statement quoted above: That ought to have been 30% oil and 50% protein.
Terry, I agree with the things on that site! But ruminants are not humans!
I’m quite happy to feed soy meal to chickens and soy oil to my car. But don’t you dare try to feed me a soy burger! Soy has many ‘issues’ as a human food and ought to be consumed in quantities of no more than a couple of grams a day (and most of that processed like soy sauce to remove the ‘bad stuff’!)
So I think we are ‘in violent agreement’ on soy as human food…
BTW, most foods have some toxic issues to deal with. Red Kidney beans will make you very sick or even kill you if not cooked at boiling (learned each year around christmas with new slow cookers and old chili recipes… ) Onions are lethal to many animals (dogs, cats) by hemolysis, but not to humans (why? don’t ask why…). Green potato skins (and the potato under them) have solanine toxin in them. Rhubarb leaves, parsnip tops, etc.
Plants don’t really want to be eaten!
So the ‘problems’ with soy are not unique. And the solutions are largely the same. Eat less than a toxic dose. Find a process that removes the toxin (boil kidney beans, chop rhubarb leaves off the stems). Feed the plant to an animal that can eat it, then eat the animal (acorns to goats). Eat only the non-toxic parts (parsnip roots are great, but wear a chem suit when harvesting, the tops give rashes…)
Because of this I see no reason to ‘ban’ soy beans; just use them wisely like all the other ‘toxic’ plants we depend on… That a whole industry is thriving on doing exactly the opposite,… well, yes, you are right, and they ought to stop it.

E.M.Smith
Editor
February 13, 2009 4:29 pm

Mary Hinge (11:26:24) :
“Smokey (09:32:37) :If the planet warms, evaporation increases.
If evaporation increases, precipitation [rain] increases.
If rain increases, droughts decrease.”
The problems are not so much the quantity of rain globally but where it does or does not fall. Increased rainfall in areas not accustomed to this as well as decreased rainfall in areas used to it WILL cause problems in food producing regions.

Can you say ‘existence proof’?
We don’t need to speculate about this with ‘ifs’. Nature has already run the experiment. Look at the Roman Optimum, the Medieval Optimum, heck, all the Optimums. During times of increased warmth, the world gets increased crop production.
Now look at all the Pessimums. Migration Era Pessimum, Iron Age Cold Epoch. etc. When the climate turns cold, crops fail and production falls. Social chaos follows.
The notion that we are doomed via crop failure if we warm up is, er, unhinged…

E.M.Smith
Editor
February 13, 2009 5:59 pm

Let’s try this again with a proper /i close of the italics…
Mary Hinge (06:14:26) : Increased CO2 can only increase plant growth if the plant has extra water, nitrogen and trace elements to support this extra growth. Availability of water throughout the growing season seems to be a problem in many parts of the world.
I can only assume that you are unaware of the studies that showed increased plant growth with higher CO2 despite no increase in water. The plants are more efficient in water use with more CO2. More CO2 mitigates drought issues for plants.
Many sources of nitrogen fixation exist, including plants that fix their own nitrogen. A red herring. Ditto trace elements. Yes, each individual soil may have some element that becomes rate limiting. So what. Most soils most of the time are not rate limited on trace minerals. If you have a problem, add some volcano dust… Trace is just another red herring.
This, IMHO, is clear evidence that most life on this planet evolved to expect 1000ppm+ and has had it for most of evolutionary history (and would want it again…)
If this was the case why is the recent era (shortly before the presence of Homo sapiens) the most biologically diverse the earth has ever been?
A rather bald assertion with nothing to back it up. That’s just a large rat hole to go explore. Does diversity matter? How to determine ‘diversity’? Does the precambrian variety of major body plans outweigh the minor species variations of today? How well does the fossil record record soft bodied critters? What was the impact of the development of sex on the rate of species creation? What is the impact of entering an interglacial on species diversity?
All very interesting questions, and all very irrelevant to this blog. So no, I will not indulge in Rat Chasing; down rat holes or otherwise.
If plants were fully satisfied with their CO2 needs at 200 ppm it would not be rate limiting. If they had had time to fully evolve toward a 200 ppm norm, they would not be rate limited on CO2. The development of C4 metabolism seems to be a partial step in that direction, so plants have been stressed ‘for a while’, but most are still C3 and even C4 is not fully adaptive.
Yes, there is an atmospheric environmental stress on plants, but that stress is too low a CO2 level; as the plants themselves testify by their growth.
BTW, if you are really interested in the problems of drought, perhaps you ought to switch ‘sides’. Drought increases dramatically during ice ages because cold air holds less water than warm air. Warmer air will bring more rains, not less. (Which, unfortunately, is why during this current couple of year cold spell California is having one heck of a drought. Though for the last week my accidental ‘prayer to the rain Gods’ has resulted in some much needed rain…)
Pessimums with poor crop growth are cold. Optimums with good plant growth are warm. Fact of history. Fact of life.
The simple fact is that plants want and need more CO2 to work at full efficiency including the efficiency with which they use water. This holds up to about 1000 to 2000 ppm CO2. That is not an accident, that is the result of directed design via evolution. It’s not gonna change ’cause you don’t like it.
That, to me, is the strongest possible argument that added CO2 is a very good thing…
You might want to take another look.