From the Smithsonian Environmental Research Center blog:
“The chief culprit appears to be climate change, more specifically, the rising levels of atmospheric CO2, higher temperatures and longer growing seasons.”
This jibes well with what NASA has been seeing globally via satellite measurements:
Surprise: Earths’ Biosphere is Booming, Satellite Data Suggests CO2 the Cause
And what has been found by the University of Wisconsin in Madison:
Greenhouse gas carbon dioxide ramps up aspen growth
Here’s the full report from the Smithsonian:
Forests are growing faster, climate change appears to driving accelerated growth
Speed is not a word typically associated with trees; they can take centuries to grow. However, a new study to be published the week of Feb. 1 in the Proceedings of the National Academy of Sciences has found evidence that forests in the Eastern United States are growing faster than they have in the past 225 years. The study offers a rare look at how an ecosystem is responding to climate change.
Liriodendron tulipifera
, or tulip poplar, is a common tree in the temperate forests surrounding the Smithsonian Environmental Research Center. Other species include sweetgum, American beech, and southern red oak. Photo: Kirsten Bauer.For more than 20 years forest ecologist Geoffrey Parker has tracked the growth of 55 stands of mixed hardwood forest plots in Maryland. The plots range in size, and some are as large as 2 acres. Parker’s research is based at the Smithsonian Environmental Research Center, 26 miles east of the nation’s capital.
Parker’s tree censuses have revealed that the forest is packing on weight at a much faster rate than expected. He and Smithsonian Tropical Research Institute postdoctoral fellow Sean McMahon discovered that, on average, the forest is growing an additional 2 tons per acre annually. That is the equivalent of a tree with a diameter of 2 feet sprouting up over a year.
Forest ecologist Jess Parker began his tree censuses his first day on the job: September 8, 1987. Photo: Kirsten Bauer.
Forests and their soils store the majority of the Earth’s terrestrial carbon stock. Small changes in their growth rate can have significant ramifications in weather patterns, nutrient cycles, climate change and biodiversity. Exactly how these systems will be affected remains to be studied.
Parker and McMahon’s paper focuses on the drivers of the accelerated tree growth. The chief culprit appears to be climate change, more specifically, the rising levels of atmospheric CO2, higher temperatures and longer growing seasons.
Assessing how a forest is changing is no easy task. Forest ecologists know that the trees they study will most likely outlive them. One way they compensate for this is by creating a “chronosequence”—a series of forests plots of the same type that are at different developmental stages. At SERC, Parker meticulously tracks the growth of trees in stands that range from 5 to 225 years old. This allowed Parker and McMahon to verify that there was accelerated growth in forest stands young and old. More than 90% of the stands grew two to four times faster than predicted from the baseline chronosequence.
Parker, his colleagues and a team of citizen scientists have tagged more than 20,000 trees at the Smithsonian Environmental Research Center. Photo: Kirsten Bauer.
By grouping the forest stands by age, McMahon and Parker were also able to determine that the faster growth is a recent phenomenon. If the forest stands had been growing this quickly their entire lives, they would be much larger than they are.
Parker estimates that among himself, his colleague Dawn Miller and a cadre of citizen scientists, they have taken a quarter of a million measurements over the years. Parker began his tree census work Sept. 8, 1987—his first day on the job. He measures all trees that are 2 centimeters or more in diameter. He also identifies the species, marks the tree’s coordinates and notes if it is dead or alive.
By knowing the species and diameter, McMahon is able to calculate the biomass of a tree. He specializes in the data-analysis side of forest ecology. “Walking in the woods helps, but so does looking at the numbers,” said McMahon. He analyzed Parker’s tree censuses but was hungry for more data.
Parker uses diameter tape or ‘d-tape’ to measure the trees. The tape is calibrated to convert the tree’s circumference, the measurement used to determine a tree’s biomass. Photo: Kirsten Bauer.
It was not enough to document the faster growth rate; Parker and McMahon wanted to know why it might be happening. “We made a list of reasons these forests could be growing faster and then ruled half of them out,” said Parker. The ones that remained included increased temperature, a longer growing season and increased levels of atmospheric CO2.
During the past 22 years CO2 levels at SERC have risen 12%, the mean temperature has increased by nearly three-tenths of a degree and the growing season has lengthened by 7.8 days. The trees now have more CO2 and an extra week to put on weight. Parker and McMahon suggest that a combination of these three factors has caused the forest’s accelerated biomass gain.
Ecosystem responses are one of the major uncertainties in predicting the effects of climate change. Parker thinks there is every reason to believe his study sites are representative of the Eastern deciduous forest, the regional ecosystem that surrounds many of the population centers on the East Coast. He and McMahon hope other forest ecologists will examine data from their own tree censuses to help determine how widespread the phenomenon is.
These findings are also important for policymakers trying to address climate change. Future carbon cap-and-trade rules will need to quantify the amount of carbon forests hold. If faster growth rates prove the norm, this could affect the formulas and the dollar value assigned to forests that are cut or conserved.
Parker and McMahon don’t expect SERC’s forest to continue growing at this accelerated rate forever. Some day the growth rate will level off. When that happens, they wonder how that will affect CO2 levels. If trees are sponges that absorb CO2, what will happen to CO2 levels in the atmosphere when the trees become saturated? It’s a question for further exploration. In the meantime, Parker will continue walking through the SERC woods, tape measure in hand carefully tracking the growth of the trees.
PNAS will make the study available online sometime this week at this link: http://www.pnas.org/cgi/doi/10.1073/pnas.0912376107.
Tulip poplar is a fast growing tree anyway.
Sweetgum is a horrible tree. It drops burrs and limbs for no apparent reason. Don’t have them anywhere near your yard. Beech is a good tree. It produces good nuts and the wood is very nice. Care must be taken in drying it properly or it will split though. Red oak is another good tree but we have had a lot of trouble with them dying because they don’t have much of a taproot so the drought has been killing large expanses of them. Very nice lumber that is quite durable. Makes excellent cabinets and stair treads.
Ok, before you pick on Geoffrey Parker, it was “TinaT” that wrote the article.
“Expected” is usually determined by a measurement known as site index. Site index can be usually fairly accurately to determine how “some” trees will grow on a particular site. For example, it is fairly easy to determine the site index of a plot in the southeast where people grow pine trees. The site index is often a very good indicator of how much wood your land can produce.
I’m assuming that Mr. Parker went back to records (rainfall, etc) to control the result. Ground water is a very important component in how fast a piece of land will produce wood products. However, there is a limit to how fast or how slow you can grow a certain species on a certain soil type with a particular amount of rain.
I would assume that the limit that Mr. Parker referred to (perhaps not translated correctly by TinaT) is that eventually trees reach a point where the annual growth levels off no matter how much good stuff you input. They will continue to grow for decades and centuries, but at a much slower rate. The forests that he is looking at are probably not old growth North American forests. The trees may still be fairly young.
Lance (13:34:24) :
I agree. It’s a telling slip of the tongue.
So let’s see. Trees grow faster if the season is longer, and there is more CO2. So tree ring data is not an indicator of just temperature then. Seems to me you lengthen the growing season, without changing the summer temperature and you get larger rings. Increase CO2 and not the temperature you get larger rings. This kinda discredits their entire temperature reconstruction doesn’t it. So Mann et al are wrong according to this for using treerings as a temperature proxy.
juanslayton,
I agree its an interesting study.
I posted it because it appears to have the same flaw as this articles study. Namely, the trees lifecycle doesn’t appear to be part of their model.
However, it is odd that the rings don’t appear to reflect the the cycle of temperature oscillation over the extended period of time. This could be due to tree growth rates and the temperature cycle they were exposed to during peak growth.
“Could the precipitation association reflect anything more than the lower trees getting more runoff than the higher? Do they do anything to try to assess the effects of runoff?”
Very good question, I haven’t seen anything yet to indicate they did.
We know temperature drives CO2
source: http://pubs.acs.org/subscribe/journals/ci/31/special/may01_viewpoint.html
We know vegetation doesn’t process as much CO2 in hotter years and stores carbon in the soil which is broken down and released as CO2 the next year.
source: http://news.bbc.co.uk/2/hi/science/nature/7620921.stm
So it seems logical, assuming the temperature at higher elevations was higher, that the trees at those levels would not have the surrounding forest lower elevations have which likely insulates (cools) lower elevation forests along with the additional moisture from run-off.
I’d also be interested to see of the trees at the edge of the lower elevation forests exhibit the same characteristics as higher elevation growth.
One way or the other, a tree isn’t just another tree ; )
Smokey (18:54:52) :
JDN (18:24:12):
“This article is more bad science, and, you all are participating.” Well, I notice that JDN is participating, too.
But JDN is not the arbiter of what is bad science. [He may think he is, but the Wikipedia link gave him away.]
In fact, CO2 is the rate-limiting factor in plant growth, as Prof Freeman Dyson points out.
========================
Smokey: Wikipedia is quick and pretty decent. If you want a non-web reference, try Voet & Voet’s Biochemistry 3rd edition, pp. 898-899. I’m sure you can find a few decent plant science references if you try. Try PubMed. I’m sure you’ll find that enjoyable. Please cite some articles that contradict my point if you can. PhD scientists are, in fact, the arbiters of bad science. That’s peer review for ya. Thanks for recognizing that fact.
You can’t be serious about citing Freeman Dyson. I laugh in your general direction. He has zero pubs on this topic. Check PubMed. He proposed theoretical trees for a living and is not an expert on any related topic, as far as I can tell. Nothing you’ve said contradicts or even addresses my point.
Let’s give you some further evidence of my arbiterness. Take your cited study by U. Ill:
•In soybean, elevated CO2 stimulated C3 photosynthesis and respiration
This is almost a truism. C3 photosynthesis is *the* incorporation step for CO2. You’ll notice that they didn’t make claims about this increase being general. In biological systems, inputs such as CO2 incorporation must be matched to utilization, otherwise you have generally toxic accumulation of intermediate products. Soybeans grown under ideal conditions may have plenty of head room to increase utilization. At some CO2 concentration soybeans *must avoid* incorporating additional CO2 in order to survive. This article (http://www.jstor.org/stable/40021816?seq=1) Fig. 4 & Table 2 illustrates that nicely. How did I know that this must be true? I must *actually* be the arbiter of bad science.
•In corn, contrary to predictions, elevated CO2 increased C4 photosynthesis
You’ll notice that they say “contrary to predictions”. Obviously there is some evidence that CO2 decreases C4 photosynthesis. Once again, plants regulate CO2 intake. Just as animals don’t necessarily grow a larger skeleton when fed a greater amount of food, plants must have the ability to regulate input of carbon to utilization and won’t necessarily grow faster/larger when CO2 goes up. Trees are particularly complicated. From what I’ve seen of the literature, science is still discovering their secrets.
_Jim (18:55:26) :
Would not a higher concentration THEN also result in a higher percentage for the variable conditions listed above?
You appear to be making some point about the variability of CO2. This not relevant to my point or to the point of the article.
The article implies that adding CO2 plus a longer growing season for trees leads to increased growth. The longer growing season (if it actually exists) would seem likely to increase tree mass. Trees tend to ignore temperature-based growing seasons and shed their leaves based on the length of the day & genetics. As presented, the original article is very poor. They don’t prove their case. I see people on this blog jumping all over the idea that increased CO2 leads to increased plant mass in all cases. This is far from proven by this article or any other. They then go on to make the laughable case that this forest is somehow a carbon sink that is temporarily holding man-made CO2 in abeyance. I’m in Maryland, and, developers in this state cut down huge swaths of forest in the relentless pursuit of development around Baltimore/DC over the same period of time. See these maps (http://www.dnr.state.md.us/forests/planning/sfla/indicators/forest_loss.htm http://www.dnr.state.md.us/forests/planning/sfla/indicators/devrank.htm) for some idea of the forest loss. Who are these guys kidding with their carbon sink idea? Not in Maryland baby. Also, when you start cutting down patches, you get more trees that receive high sunlight, possibly promoting growth. The devil is in the details. If this blog has sustained interest in this topic, you guys should invite a forestry person to audit this paper. I’m sure there is more to this junk paper.
Keep the objections coming. I usually shut up about lack of scientific understanding, but, I’d like to see the defeat of AGW, and, it doesn’t help when your own people are spouting nonsense and falling into the trap laid by the enemy. I assure you that I’m no proponent of AGW.
If you want to double check, google “U.S. corn yield trends” or something similar.
The Smithsonean blog states that:
Forests and their soils store the majority of the Earth’s terrestrial carbon stock.
I don’t know if that is correct as I think that limestone harbors more carbon.
Will this bud into a new movement on “Tree Growth Change” where trees will eat small children, dogs and cats ?
I recall reading an article last year (don’t recall the source), that stated that due to the rise in CO2, the earth in the future will be overtaken by weeds. The article was clearly one-sided, propagandist and alarmist, especially since it made no mention of the idea that if weeds are growing faster due to increased CO2 levels, so also are most all of the beneficial plants (trees, flowers, shrubs, herbs, edible crops, coffee, cotton, flax, etc). And it appears that the author of the article was not familiar with a machine called the lawnmower or the weed trimmer.
The idea that weeds are 100% malevolent is displaced. For example, many property owners will spend sums of money and time to mitigate Dandelion (Taraxacum) growth in their lawns, most often through the spreading of toxic chemicals. The effort is almost always purely an exercise in aesthetics (aside from allergic sensitivities in some individuals). However the Dandelion is beneficial to early bee pollination, and also has beneficial nutritional and medicinal properties.
That an increased CO2 level is beneficial to plants is well known to professional greenhouse operators, and this is the reason why some operators will pump in additional amounts of CO2 to spur the growth of the plants being cultivated inside.
_Jim (18:45:28) :
I’m sure I misunderstood your comment. It looked like you said smoke from burning wood is pollution. If you did it was a joke?
The culprit is the pollutant CO2. No wonder greenies hate it. Greater plant growth means the Earth will have a higher carrying capasity. The loudest shouting of the eco crowd is that there should only be 500 million people on earth. The sooner the population is killed down the better.
I’m not sure how they expect to survive as very few of them can actually create as much as they consume. It takes nearly 100 million people around the world to create and provide for the modern electronic industry.
I fear they will learn very soon as the grain supply production of the world is now only 2 weeks ahead of consumption. The elietist ecos think they can eat, their food comes from the supermart, it just will cost more. The poor of the world will starve while their food is sold to the ecos…………..for a while.
@JDN (20:26:41) :
“Trees tend to ignore temperature-based growing seasons and shed their leaves based on the length of the day & genetics. ”
JDN, would you cite your source for this statement? My primary data disputes this statement. My observations have been that trees do not ignore temperatures. A tree which has branches overhanging my property sheds its leaves as a function of the fall temperatures. In some years, 95% of all leaves have fallen by October 31 (cold fall weather), in other years, 95% of all leaves have not fallen until early December (warmer than normal fall weather).
I have also seen Salix babylonica sprout buds in early March during an abnormally warm temperature period, almost 60 days earlier than normal for my geographical location (upstate NY).
Enough already! This group took a quarter of a million observations. Someone actually performed real observational science, building a valuable data set. The collector is entitled to characterize the data as he sees fit. I suspect he will be proud to share this data with anyone else who wants to take a crack at it. I don’t really care about calling something a culprit or not. The only thing that matters is the data, and Jess Parker is to be commended for this arduous undertaking.
This is a scientific free comment. It is my own memory of my experiences. As a young boy the weather was warm and wonderful (1930s) .When my boys were young the weather was much cooler(the same place, South Sweden ,55 deg N.).We sat often in the summer house in front of a fine warm fire.
On the job (long experience)i the North (65 deg. N). The weather became much colder than normal. Seedlings died of frost and early snowfall. More re-plantation of seedlings than normal. Norwegian glaciers on the other side of the border increased. (Dr. Hansen and Dr. Schneider started to fight the cold. That I have learnt much later.) Famine was a threat, Newsweek.
The warm weather came back and Dr Hansen and Dr. Schneider changed side. Global warming slowed down and we got Climate change instead. Earlier we had only had cold and warm weather. Suddenly climate changes, and changes to the warmth was said to be dangerous.
Of course earlier we have had summer climate and winter climate. How wonderful it was when the sun came up in the spring and melted metre thick ice on the lakes and one to 1½ metre snow thawed awy. I never saw a particle of carbon dioxide. No wonder it is colourless. No it was the sun that gave us warmth and light. Our forefathers knew it. They organized big fiestas to please the sun to come back.
IPCC with Mr Maurice Strong upto Dr Pachauri has taken over the playground and severely damaged the play with lie and spuriousness. It is time that our free clever scientists take over the play.
This was about tree growth. In the area where I worked we had an average growth about 1½-2 cubic metres a year and hectare (65 deg, N) In the South of Sweden (55 deg N) the average growth was about 4.0-5.0 cubic metres per hectare and year. The figures are from inventories 1941-1945.No culprits, no carbon dioxide to blame.
You have done a wonderful job Anthony. Thank You , Jorgen O
Here is a little more observational science, unless you think they have been rigging it for 50 years. http://www.esrl.noaa.gov/gmd/webdata/ccgg/trends/co2_data_mlo.pdf
Anthony, it looks like a good volunteer’s project across the country.
I don’t think anybody’s worried, but it does offer another data point in support of the reality of global climate change, and this information will help scientists estimate how much we can expect natural CO2 sequestration processes to offset accelerated human emissions.
Scientist For Truth
Don’t forget that the intrepid and incisive Fred Pearce of the Grauniad, who exposed all the problems at CRU and IPCC, is also the man who brought us this little ray of sunshine:
http://www.amazon.co.uk/Last-Generation-Nature-Revenge-Climate/dp/1903919878
So there are 3 parts to the “problem”: elevated CO2, longer growing seasons and higher temperatures. I presume rainfall and other potential variables have remained the same.
As we have a live experiment going on here, why don’t they determine the percentage contribution of each of these 3 parts. We can then retrofit this to all the old dendro records so we can know for sure exactly what was going on in the thousands of years that they have on record.
Can’t be done? In which case, we have no idea about how temperature affects tree growth compared to other factors.
It’s obvious that mankind is collectively getting dumber by the day, month, year, century, and millenium. Imagine what the world would be like today if the people today were faced with the problems our ancestors encountered at the beginning of the Little Ice Age. Ah… no, let’s not go there.
While it is natural for people to think their children will be smarter than they were, and for children to think they are smarter than their parents, the reality is very different. (It’s actually a crap game and children rarely pass their parents until after the second funeral.)
Here we are (I’m speaking of “MANKIND” not you and me:-) sitting around picking lint out of our navals and worrying about the weather. Haven’t we been doing this for the past 6 million years?
Oh Eve! If you hadn’t eaten the forbidden fruit, things would have been so much easier.
_______________
Now, where were we… oh yes, the weather……..
From http://www.mdvaden.com/redwood_climbing.shtml
If you have the time for it, I highly recommend Richard Preston’s High Trees. It was a delightful read, with compelling characters, and loads of new insights into the canopy of the great red wood forests of the Pacific coast.
And yes, the red woods are growing faster, due no doubt to the increases of CO2.
So step on the gas and give those magnificent giants a squirt of plant food.
The US Forest Service stated a short time ago (weeks?) that forest-grown Aspen have grown markedly faster with elevated levels of CO2 in the atmosphere while indigenous varieties of Oak in the same area show no sign of increased growth over the past 50 years.
Isn’t this where the AGW’ers chime in that climate change will cause vegetative overgrowth of invasive species and we will all die from killer weeds? (Gawd I’m getting good at this spin.) Or am I just vaguely remembering a horror movie from the 50’s? No, that one was about giant stink bugs, or ants, or something.
@ur momisugly GaryPearse (00:27:06) :
The “USA National Phenology Network” is looking for volunteers.
http://www.usanpn.org/