From the University of Michigan
U-M ecologist: Future forests may soak up more carbon dioxide than previously believed
![36944_web[1]](http://wattsupwiththat.files.wordpress.com/2011/10/36944_web1.jpg?quality=83 "36944_web[1]")
An aerial view of the 38-acre experimental forest in Wisconsin where U-M researchers and their colleagues continuously exposed birch, aspen and maple trees to elevated levels of carbon dioxide and ozone gas from 1997 through 2008. Credit: David Karnosky, Michigan Technological University
ANN ARBOR, Mich.—North American forests appear to have a greater capacity to soak up heat-trapping carbon dioxide gas than researchers had previously anticipated.
As a result, they could help slow the pace of human-caused climate warming more than most scientists had thought, a U-M ecologist and his colleagues have concluded.
The results of a 12-year study at an experimental forest in northeastern Wisconsin challenge several long-held assumptions about how future forests will respond to the rising levels of atmospheric carbon dioxide blamed for human-caused climate change, said University of Michigan microbial ecologist Donald Zak, lead author of a paper published online this week in Ecology Letters.
“Some of the initial assumptions about ecosystem response are not correct and will have to be revised,” said Zak, a professor at the U-M School of Natural Resources and Environment and the Department of Ecology and Evolutionary Biology in the College of Literature, Science, and the Arts.
To simulate atmospheric conditions expected in the latter half of this century, Zak and his colleagues continuously pumped extra carbon dioxide into the canopies of trembling aspen, paper birch and sugar maple trees at a 38-acre experimental forest in Rhinelander, Wis., from 1997 to 2008.
Some of the trees were also bathed in elevated levels of ground-level ozone, the primary constituent in smog, to simulate the increasingly polluted air of the future. Both parts of the federally funded experiment—the carbon dioxide and the ozone treatments—produced unexpected results.
In addition to trapping heat, carbon dioxide is known to have a fertilizing effect on trees and other plants, making them grow faster than they normally would. Climate researchers and ecosystem modelers assume that in coming decades, carbon dioxide’s fertilizing effect will temporarily boost the growth rate of northern temperate forests.
Previous studies have concluded that this growth spurt would be short-lived, grinding to a halt when the trees can no longer extract the essential nutrient nitrogen from the soil.
But in the Rhinelander study, the trees bathed in elevated carbon dioxide continued to grow at an accelerated rate throughout the 12-year experiment. In the final three years of the study, the CO2-soaked trees grew 26 percent more than those exposed to normal levels of carbon dioxide.
It appears that the extra carbon dioxide allowed trees to grow more small roots and “forage” more successfully for nitrogen in the soil, Zak said. At the same time, the rate at which microorganisms released nitrogen back to the soil, as fallen leaves and branches decayed, increased.
“The greater growth has been sustained by an acceleration, rather than a slowing down, of soil nitrogen cycling,” Zak said. “Under elevated carbon dioxide, the trees did a better job of getting nitrogen out of the soil, and there was more of it for plants to use.”
Zak stressed that growth-enhancing effects of CO2 in forests will eventually “hit the wall” and come to a halt. The trees’ roots will eventually “fully exploit” the soil’s nitrogen resources. No one knows how long it will take to reach that limit, he said.
The ozone portion of the 12-year experiment also held surprises.
Ground-level ozone is known to damage plant tissues and interfere with photosynthesis. Conventional wisdom has held that in the future, increasing levels of ozone would constrain the degree to which rising levels of carbon dioxide would promote tree growth, canceling out some of a forest’s ability to buffer projected climate warming.
In the first few years of the Rhinelander experiment, that’s exactly what was observed. Trees exposed to elevated levels of ozone did not grow as fast as other trees. But by the end of study, ozone had no effect at all on forest productivity.
“What happened is that ozone-tolerant species and genotypes in our experiment more or less took up the slack left behind by those who were negatively affected, and that’s called compensatory growth,” Zak said. The same thing happened with growth under elevated carbon dioxide, under which some genotypes and species fared better than others.
“The interesting take home point with this is that aspects of biological diversity—like genetic diversity and plant species compositions—are important components of an ecosystem’s response to climate change,” he said. “Biodiversity matters, in this regard.”
###
Co-authors of the Ecology Letters paper were Kurt Pregitzer of the University of Idaho, Mark Kubiske of the U.S. Forest Service and Andrew Burton of Michigan Technological University. The work was funded by grants from the U.S. Department of Energy and the U.S. Forest Service.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
But, but, but…….
“Increasing CO2 levels would only be beneficial inside of highly controlled, enclosed spaces like greenhouses.” SkS
They put a whole forest in a greenhouse? /sarc.
Eudoxus
Steepdown is right, CO2 can absorb “heat” in the form of some IR wavelengths but not “trap” it. The CO2 molecule increases in internal energy (vibration) upon absorption which could then be dissipated through collisions with other molecules into translational motion or through radiant emission. Heat by definition is the transfer of energy not the stored energy so while the CO2 molecule has increased internal energy in vibration this energy is not “heat”.
Whenever I see “heat trapping” my eyes roll, and I know the author has drunk the Kool-Aid.
Think of it this way, what if I said “light trapping CO2 molecule”.
And this is a new finding how? Greenhouse horticulturists have known this since they put their first little baby tree in a greenhouse.
Plus! It takes a lowly armchair reader to state the obvious. When trees hit wall, cut them down and plant new ones. Spewed coffee all over my puter when I read that one.
Who are these researchers? Kids???? Do they NOT do liturature review anymore in preparation for their research proposal? And who sat on the grant committee and decided this study would produce new information?
“Co-authors of the Ecology Letters paper were Kurt Pregitzer of the University of Idaho, Mark Kubiske of the U.S. Forest Service and Andrew Burton of Michigan Technological University. The work was funded by grants from the U.S. Department of Energy and the U.S. Forest Service.”
Science is always settled. It just continously keeps re-settling in different places. Darned frustrating! AGW science is like Whack-a-Gore on steroids. Only after one whack, Gore-boks don’t seem to be showing up in the same holes. Odd, that.
@Gilles says:
October 14, 2011 at 5:25 am
“The best way is actually to plant more trees and to use more wood, the carbon is sequestrated in the lumber for many years while news trees are growing in place of the used ones.
======================================================
Or move back to paper grocery bags. No oil used and the carbon is sequestered in landfills for years.
Or print more National Geographics. No one throws those away and the carbon would be sequestered for centuries in attics across America.
You’re on to something, Gilles.
So let me get this straight, they spent all of this money to come to two well known conclusions:
Change an environment and the organisms present will adapt or die.
Plants really love the CO2.
Man I really need to get into this climate science business, get paid to learn absolutely nothing new.
Patrick Davis says:
October 13, 2011 at 11:05 pm
From the article “North American forests appear to have a greater capacity to soak up heat-trapping carbon dioxide gas than researchers had previously anticipated.”
Heat-trapping, really?
Quite so: replace with “North American forests appear to have a greater capacity to fix carbon dioxide than researchers had previously anticipated.”
Look at this typical clueless green idiocy
new-zealand-oil-spill-should-highlight-the-death-of-worlds-coral-reefs
But but but … the astrolabe reef isn’t a coral reef! It is just plain old rock! Indeed we don’t have coral reefs as such in New Zealand – the water is too cold. Having our beautiful pristine beaches covered in oil and rubbish is bad enough without these brainless twerps trying to exploit the tragedy to push a completely unrelated issue.
Rory Barclay says:
October 13, 2011 at 10:31 pm
“Zak stressed that growth-enhancing effects of CO2 in forests will eventually “hit the wall” and come to a halt. The trees’ roots will eventually “fully exploit” the soil’s nitrogen resources. No one knows how long it will take to reach that limit, he said.”
And what results in the study support this conclusion? They already had their expectations proven wrong once, but they turn around and state this as a definite that there is a hard limit to the nitrogen cycle?
—
The need to get a scientific paper past some critical reviewer often leads to some disfigurement.
Statements inserted at the revision stage often stick out like erratic boulders, without any connection to the surrounding context or the main conclusion of the manuscript.
The irony of course is that we will cut down those trees to make the paper upon which we write those global warming laws…
Love it. I’ve always thought is was folly to recycle paper. Trees eat CO2 and buried paper lasts decades if not centuries.
Oh my, sound the alarm, the amazon might come to an end because, well, the nitrogen cycle might stop peddling due to too many roots insnared in the trees wheel o’ life after a billion years. And who’s to blame? Well, apparently, the climate communist hippies say they’re responsible. :p
Before everyone gets all bound up in calculations as to how many trees, how many years, how much land, how much CO2 is netted out, etc., don’t forget to remind yourselves that the bigger question is: Does any of this matter?
If you’re not careful, you’ll find yourselves falling in with the CO2-must-be-controlled crowd by advocating replacing windmills and solar panel fields with trees for the wrong reason. The right reasons are that trees are more visually appealing and are make economic sense so people will plant forests without government inducements, as they have been doing for decades already.
It was an interesting finding, but it wasn’t an answer to a “problem” unless the “problem” indeed exists.
Dr Ware,
They reported that ozone was added to “some” of the plots. I see that as two different experiments run side by side.
What a bunch of dumb s****…..
We know that trees, C4’s, evolved when CO2 levels were in the thousands.
We know that trees shut down when CO2 levels drop to around 200-250 ppm.
..and they don’t have the sense to know that our current CO2 levels are limiting to trees!
I have to admit I’m a bit perplexed by the idea that a tree has to get nitrogen out of the ground, when the atmosphere is 4/5 nitrogen. I can see how nitrogen fixed in the ground is more efficiently used by the tree than atmospheric nitrogen, and that when the ground supply runs short the growth rate might SLOW a bit as the tree switches to the less-efficient nitrogen uptake, but not that it would be a hard limit.
“Filbert Cobb says:
October 14, 2011 at 6:42 am”
How does that address the “heat trapping” claim for CO2?
Geoff Sherrington says:
October 14, 2011 at 1:32 am
Many people do not realise how badly they are being scammed by schemes to “put more carbon into soil” or to “grow more trees for emission credits”. It’s the next closest move to outright theft. You’re daft if you invest in these credit thingos. Or of criminal mind if you start one.
Turn over REDD and you will find Maurice Strong. Look a bit further and you find names like Gore, Clinton, WWF. Carbon credits for not cutting down trees — this year. Once the carbon credits are paid, who can say what will happen. If the trees are sold to someone else, will the money be returned? What if it has already been spent?
Studies like this, showing that trees trap more carbon than originally thought improve the economics for REDD. They improve the economics of buying off corrupt officials to look the other way as third world people’s are displaced from their land to make way for carbon farms. Tropical forest converted to oil palm on a global scale. How many indigenous people’s can show a “deed” for the land their ancestors have lived on for thousands of years?
U M link: U-M Ecologist: Future Forests May Soak Up More Carbon Dioxide Than Previously Believed, Helping to Buffer Climate Change
Lead author: Donald R. Zak, Ph.D.
“In addition to trapping heat, carbon dioxide is known to have a fertilizing effect on trees and other plants, making them grow faster than they normally would. Climate researchers and ecosystem modelers assume that in coming decades, carbon dioxide’s fertilizing effect will temporarily boost the growth rate of northern temperate forests.”
——————————–
carbon dioxide is known to have a fertilizing effect on trees and other plants
fertilizing effect? Here I thought CO2 was necessary for plants rather than a growth promoter.
I thought no CO2 no plants and no plants then no O2.
Who’d-a-thunk…………fertilizing effect, huh?
Here is the problem with scientists who are like these people in this article. They first study something that they do not have an elementary understanding of. Then they write models or use models written by others in that same camp.
Finally, the result is obvious: a piece of *@&$ article that any 10 year old would have done just as well if not better since they actually use SOURCES and use FACTS. Just terrible if you ask me.
Why? Well let’s look at the facts.
Plants in general are LIMITED by one of several factors. This has been known for hundreds of years. The growth will continue on faster then average forever. (Barring something strange occurring such as a drought). This is because the increased CO2 has made that not a limiting resource. The growth seen will continue and unless they starve the plants on purpose (water, nitrogen, etc), their growth as evidenced will continue until they do reach the limit. Perhaps sunlight is a limit as well?
Who knows. But the fact remains that instead of analyzing the growth patterns from a correct point of view in that the growth is being limited at a new level due to “some other lack” they have not found what this lack is and instead pontificate on about lack of nitrogen with no idea if it is sunlight, or temperature or soil nutrients (not just nitrogen mind you) that is causing this lack of further expansion in growth.
And the entire part about ozone? Ozone levels in our country have been heading downwards over the last 30 years approx. In fact, ozone action days are at an all-time low today. So the idea that this will reverse itself (the trend) is at best stupid speculation and more probably a blantant lie.
In fact, if you chart pollutants over the last 100 years, the downward trend makes it impossible to determine when the CAA was passed. (Julian Simon) Funny how facts get in the way of good stories isn’t it?
In other words, studies like this are made by scientists who do not deserve that title. They have in fact written drivel that a 10 year old would not have because they would have actually gotten the basic facts correct.
My only question is of course in similarity with other studies like this: Do these people know that they are wrong, or are just ignorant?
The Monster says:
October 14, 2011 at 7:41 am
I have to admit I’m a bit perplexed by the idea that a tree has to get nitrogen out of the ground, when the atmosphere is 4/5 nitrogen. I can see how nitrogen fixed in the ground is more efficiently used by the tree than atmospheric nitrogen, and that when the ground supply runs short the growth rate might SLOW a bit as the tree switches to the less-efficient nitrogen uptake, but not that it would be a hard limit.
—
Atmospheric nitrogen is N2. Living organisms need nitrogen as ammonia (NH3). Only relatively few soil bacteria can convert N2 to NH3; plants themselves can’t. This process can be bypassed through the use of chemical fertilizers that contain ammonia and/or nitrate, which can be reduced to ammonia by other organisms. Alternatively, nitrogen fixation can be promoted by leguminous plants, the roots of which host nitrogen-fixing bacteria.
Where the idea of a hard limit to the capacity of nitrogen fixation comes from I don’t know, and it is interesting to note that no such limit was observed in the current study.
Expecting don’t make it so.
Simulating expected but not known conditions at a future time and finding trees work better than thought accomplishes research that might be good to know except the atmospheric conditions they claim are expected have not been proven to be expected.
In “Little House in the Big Woods,” by L.I. Wilder, Pa complains that he just can’t farm in Minnesota – he clears his field every year, but the trees just keep growing back! Our friend who lives on his grandfather’s old tree farm near DeSabla says the same thing – he says, you can’t kill the forest, you can cut it and change it, but it will always grow back.
We have a little property in the woods, and I notice, they’re right. I have to remove baby trees from the driveway every year. I brought some cedars home to Chico, but only one of the seven has made it – and it’s doing fairly well in my front yard here at my home. Right now I have a bay and a red bud in pots, trying to decide, where should I place them. I placed a bigger rescued redbud in my yard and after a sketchy year it has grown a couple of feet and started to fill out very nicely.
A dogwood we rescued from a crack in the sidewalk 20 years ago is now over 15 feet tall with a huge crown of flowers every spring. We planted that at a house we later sold but we drive by every fall to see the color and every spring to see the flowers.
Some of my best little trees are five bays I found uprooted during a project in Bidwell Park. The city crew was digging a trench to lay drainage for a new subdivision, and they’d just torn out 9 very nice little trees, and there they were, tops buried in mud, and roots sticking up in the air. With permission of the crew, my husband and I dug them out and put them in our bike cart and brought them home. We didn’t know where to put them, so four of them never made it out of the pots. The five that made it are all over eight feet tall and at least that big around.
I haven’t always had the best luck – I spent a lot of time digging out and transplanting some little dogwoods to my yard here – our newfoundland just attacked them. For some reason, he just decided to eat them, we never figured it out. “Dog” – woods?
But the successes I’ve had, when I think about it, are probably the only thing I have done that will be truly appreciated in the future.
thanks Anthony, great idea.
I don’t know why they think low-level oznone would increase, pollution is decreasing.
Trees bleed sugar from their roots to benefit bacteria and fungi. Nitrogen fixing bacteria get more food when trees grow faster.