Higher density means world forests are capturing more carbon
Forests in many regions are becoming larger carbon sinks thanks to higher density, U.S. and European researchers say in a new report.
In Europe and North America, increased density significantly raised carbon storage despite little or no expansion of forest area, according to the study, led by Aapo Rautiainen of the University of Helsinki, Finland, and published in the online, open-access journal PLoS One.
Even in the South American nations studied, more density helped maintain regional carbon levels in the face of deforestation.
The researchers analyzed information from 68 nations, which together account for 72 percent of the world’s forested land and 68 percent of reported carbon mass. They conclude that managing forests for timber growth and density offers a way to increase stored carbon, even with little or no expansion of forest area.
“In 2004 emissions and removals of carbon dioxide from land use, land-use change and forestry comprised about one fifth of total emissions. Tempering the fifth by slowing or reversing the loss of carbon in forests would be a worthwhile mitigation. The great role of density means that not only conservation of forest area but also managing denser, healthier forests can mitigate carbon emission,” says Rautiainen.
Co-author Paul E. Waggoner, a forestry expert with Connecticut’s Agricultural Experiment Station, says remote sensing by satellites of the world’s forest area brings access to remote places and a uniform method. “However, to speak of carbon, we must look beyond measurements of area and apply forestry methods traditionally used to measure timber volumes.”
“Forests are like cities – they can grow both by spreading and by becoming denser,” says co-author Iddo Wernick of The Rockefeller University’s Program for the Human Environment.
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  IMAGE:Forests in many regions are becoming larger carbon sinks thanks to higher density, US and European researchers say in a new report. In Europe and North America, increased density significantly…Click here for more information. |
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The authors say most regions and almost all temperate nations have stopped losing forest and the study’s findings constitute a new signal of what co-author Jesse Ausubel of Rockefeller calls “The Great Reversal” under way in global forests after centuries of loss and decline. “Opportunities to absorb carbon and restore the world’s forests can come through increasing density or area or both.”
To examine how changing forest area and density affect timber volume and carbon, the study team first focused on the United States, where the U.S. Forest Service has conducted a continuing inventory of forest area, timberland area and growing stock since 1953.
They found that while U.S. timberland area grew only 1 percent between 1953 and 2007, the combined national volume of growing stock increased by an impressive 51 percent. National forest density increased substantially.
For an international perspective, the research team examined the 2010 Global Forest Resources Assessment compiled by the UN Food and Agriculture Organization (FAO), which provides consistent figures for the years 1990 to 2010.
The data reveal uncorrelated changes of forest area and density. Countries in Africa and South America, which lost about 10 percent of their forest area over the two decades, lost somewhat less carbon, indicating a small rise in forest density.
In Asia during the second decade of the study period, density rose in 10 of the region’s 21 countries. Indonesia’s major loss of density and sequestered carbon, however, offset any gain in carbon storage in other Asian nations.
Europe, like the U.S., demonstrated substantial density gains, adding carbon well in excess of the estimated carbon absorbed by the larger forested area.
Says study co-author Pekka Kauppi, of the University of Helsinki, Finland, “With so much bad news available on World Environment Day, we are pleased to report that, of 68 nations studied, forest area is expanding in 45 and density is also increasing in 45. Changing area and density combined had a positive impact on the carbon stock in 51 countries.”
Related, see Earth’s biosphere is booming, CO2 the cause
More Co2 in the atmosphere promotes more growth and causes more CO2 to be absorbed during growth cycles but also increases the amount of plant material to decay during dormant periods. This increases the natural contribution to the Carbon cycle both sink and source.
The reason we never ratified Kyoto is because in the draft protocol there were carbon “credits” for forest expansion. Then when it turned out the U.S. was responsible for so much forest expansion both here and abroad and that the forest credits would allow us to emit as much more carbon as we wanted and just plant more trees to nullify it. So in the final version of the protocol the forestation credits were vastly reduced and Bill Clinton said “thanks but no thanks, we’ll just continue planting trees and y’all can go pound sand”.
If the woodlands are denser, then there is more transpiration, more heat moving upwards carried away by the extra water vapor. We’re familiar with the Urban Heat Island (UHI) effect driving up surface temperatures. Do thicker woodlands lead to an increased Forest Cool Area effect? We already see this in the Amazon rainforest, which ends up generating its own thunderstorms providing further cooling during the day. Will these denser woodlands worldwide significantly lower surface air temperatures on land?
Interesting – as far as it goes. But . . .
I have volunteered for the local county conservation district in their annual plant sale. This started about 15 years ago and has grown so large that they now use a crew from AmeriCorps. My first stint was about 12 years ago, and I did 10 seasons before the volume overwhelmed us aging volunteers.
The first year I planted ten Ponderosa Pines along the driveway and another 20 trees of different variety. The pines were about a foot tall and pencil thin. Those first trees are now about 8 inches in diameter at belt height. I’ve continued to plant these and other tree species every year. Via help from all the county conservation districts throughout the State of Washington, hundreds of folks are doing the same and turning city lots and mini-ranches (10 to 20+ acres) into wooded parcels – parcels that were mostly treeless 20 or 30 years ago. Many riparian areas (I have about 10 acres of such) are now being protected from grazing and the trees and woody shrubs have filled in and are much healthier – encroaching on the pasture.
I’ve read that wood is about half carbon by weight. I do not sense in the report presented that the folks were including the sorts of additions to the carbon depository such as I have described. If not, the carbon sink is larger than they describe and expanding.
All I know is there’s a hell of a lot of trees out there. Most people don’t realize how many trees there are because people don’t live in forests. But just looking at what I can see from the roads and and around houses there are a lot of trees. If you fly in a small plane, small because jets fly too high, you’ll see how many trees there are. Its quite a lot.
Can the alarmists stop to recite daily
these key-word reality-phrases:
“aerial plant food”
“stomatal efficiency”
“vegetative density”
“adaptive response”
“negative feedback”
and let’s not forget
“dynamic stability”
“natural cycles”
Forest density is not exactly a no-brainer for increased CO2 uptake. When forest density increases above 10x historic levels, trees compete for water and light. Biodiveristy decreases in the dark forest; the interface between forest and meadow is where biodiversity peaks. The trees that survive under these sub-optimal conditions are often sick. They do not grow efficiently. Consequently, CO2 uptake is not even close to the maximum per acre.
In a dense forest, the fire hazard grows to explosive conditions. The CO2 released from a big fire is just the beginning. It is estimated that 3x that amount is released as the dead trees rot. Harvesting the dead trees would avoid that outcome. Naturally, these harvests are blocked. Well meaning, and well-programmed urban environmental zealots cause these problems by funding enviro ‘hands-off’ forestry policies backed up by lawsuits.
Many of our forests are now 10-fold higher density than pre-european forests. Native people kept down mid-level fuels and maintained meadows through the use of fire. However, these fires did not burn the way our forests do now. Historic fires burned low to the ground. Now, big fires convert soil to hydrophobic clay, and kill everything.
Forests restored to historic conditions would reduce evapotranspiration and result in more water for fish, agriculture, and human consumption. Lower density forests can in fact be more productive than overgrown forests with sick trees. Regular tree harvests do not destory the land or the water, certainly not the way big fires do. It can take hundreds of years for a forest to recover if the soil is destroyed by a modern unnaturally hot fire.
Sorry, Bambi is not real. Real deer die in fires caused by 100 years of bad policy. Real deer also are hit by cars. We allowed trees to choke high meadows, driving deer to forage in inhabited areas. Restore the forest, restore the meadows; in return you get increased biodiveristy, smaller fires, and a lot more water.
Says study co-author Pekka Kauppi, of the University of Helsinki, Finland, “With so much bad news available on World Environment Day, we are pleased to report that, of 68 nations studied, forest area is expanding in 45 and density is also increasing in 45. Changing area and density combined had a positive impact on the carbon stock in 51 countries.”
We’re all gonna have to work harder to feed the biosphere. Everybody detune that V-8, lay in a cement patio and throw another log on the fire.
There’s that pesky plant food assertion again.
And what caused this increase in density? Maybe it was CO2, but they aren’t going to tell you that.
so you increase the supply of one of the basic plant nutrients you find that the plants grow better; perhaps they could try increasing things like water, or nitrates or phosphates, they might increase plant growth too. Shocking.
Plants sucking up carbon?
Outrageous!!
The EU wants us to pay for expensive machines to do that….
lol, yes, yet another known but too oft ignored equilibrium seeking mechanism that engages. Prolly due to Dell’s donate a dollar button at the end of a PC purchase…..
Well, if you don’t burn them they get thicker……
…this is what happens when you are required to publish, something, anything
just publish
Rock! Rock! Rock! The only long-term storage of CO2 occurs when it ends up as limestone or organic-rich rock. Yes those trees can become coal but the process takes millenia. All any of us can do is arm-wave in the short-term. No one can predict what CO2 today will end up permanently removed from the geosphere, in amounts sufficient to make a difference.
OK, everyone go up and read the post by Hoser:
Thicker forests are often under-productive fire traps, and lack meadowlands needed by many animals. Overprotection of woodlands has “Unexpected Consequences”.
Addison DeWitt says:
June 6, 2011 at 6:36 pm
Rock! Rock! Rock! The only long-term storage of CO2 occurs when it ends up as limestone or organic-rich rock. Yes those trees can become coal but the process takes millenia. All any of us can do is arm-wave in the short-term. No one can predict what CO2 today will end up permanently removed from the geosphere, in amounts sufficient to make a difference.
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Kind of a catch 22, isn’t it? We all love trees, but in the end, trees will give up the CO2, for the most part. The more trees, the more atmospheric CO2. Oh, the irony!!! The solution, of course, is to live in a barren land devoid of plant-life! …………….. Or there may be another mechanism of which we’re not aware……….
So we emitted this vast volume of extra plant food, the trees got denser, people settled in the new thick forests, and the fires are now more intense and destructive.
Sounds more like Global Growing and Forest Glowing.
We could do a LOT better at managing our new tree farms, but, as KDKnoebel says, the Greens won’t let anybody do anything of the kind.
Of note: You don’t hear of people tying themselves to trees anymore. Now they just tie the whole darn forest up in legal knots.
Sad, isn’t it? Our new tree farms are destined to go up in Green smoke.
In Scotland, they are chopping down thousands of trees, to make room for wind farms.. The loonie greens at work !!!
@ur momisugly kadaka “If the woodlands are denser, then there is more transpiration, ”
Not necessarly… there was a study that showed that the leaves on the trees actually decrease the density of stomate on the back of the leaves in a CO2 increased atmosphere, thus reducing transpiration… ie becoming more efficient with water. Nature is clever, ya see.
At around 250ppm CO2 the stomate are packed tight, which makes sense when you consider that most plant have trouble breathing below about 200ppm CO2.
Ie.. we have been just above plant subsistence levels of CO2 for the last million or so years, maybe because the ultra-lush plant growth died and was buried as it ran out of CO2 (look at the long historic levels of CO2. you will see that the large concentrations of CO2 many million years ago suddenly dropped at around the time plant life probably took off, dropping rapidly to bare subsistence levels)
And finally we are releasing a tiny proportion of what got buried.
And the Greens want to stop us ??????
And Abbott prefers to plant more trees.. obviously hasn’t got the message 😉
I always wondered if agricultural cultivation of vast barren lands by man, going on for thousands of years, has ever been taken into account as an important CO2-absorbing and climate-moderating factor by those who, like IPCC and Dr. Ira Glickstein, are so fond of playing games with the formulas.
It may very well be that human activity, in the final reckoning, is more beneficial than it is destructive, as opposed to the purely hypothetical “natural state” of the planet.
Dr Patrick Moore (PhD in Ecology) comments extensively on forrest management and biodiversity in his last book. Presenting slightly more balanced views comparing to those of Hoser here above.
I think that societies and nations can afford environment protection once they become sufficiently rich, with developed economies. Poverty kills the environment. One may have a look on the history and timing of laws protecting air, water, soil – rich countries introduced it first, quite long time ago. Poor people – having agriculcture of low productivity or pastoral economy – are capable of putting quite a high load on their environment.
As trees grow, they get bigger, need more CO2 to continue to grow.
I thought this was basic and not in need of a research grant to discover.
Only a matter of time before “Man’s carbon emissions causing obesity crisis in trees.”