Researchers find Europe's forests moving toward carbon sink saturation point

Aug 19, 2013 by Bob Yirka report
Biogradska forest in Montenegro. Credit: Wikipedia.

(Phys.org) —A team composed of researchers from several European countries has found that, due to aging forests and deforestation, Europe's forests appear headed for a carbon sink saturation point much earlier than anticipated. In their paper published in Nature Climate Change, the team describes that the amount of carbon dioxide being absorbed by forests on the European continent has been slowing since 2005.

The amount of carbon dioxide in the atmosphere can be reduced in two ways. The first and most obvious is for people to stop pumping so much of it into the air. The second is to take more out (i.e., create carbon sinks), which for now at least, means planting more trees. As many of us may recall from grade school, trees pull carbon dioxide out of the air and store it in new growth—in return, is released into the atmosphere. Absorbed carbon remains in the wood until it either rots or is burned. For that reason, those concerned with reducing the amount of carbon in the atmosphere and the associated rise in promote the idea of planting more trees, while reducing .

Europe is unique in that it's one of the few places on the planet that has more trees now than it did a century ago. Replanting was initiated as part of rebuilding the continent after the ravages of two World Wars—particularly in France and Germany. Unfortunately, trees don't live forever—those trees planted after the wars have grown so old that their ability to absorb carbon is slowing. The research team estimates these trees will reach a by 2030. The researchers also found that some parts of the continent have seen some deforestation as trees are cut to make room from expanding towns and cities. Cutting down trees and using the wood from them isn't a problem of course, it's when they are cut and not replaced that the problem occurs. For that reason, the research team suggests that old wood forests become part of harvesting programs to replace older trees with newer growth.

The researchers also note that older forests are more at risk—fires, disease and insects all contribute to killing trees, allowing the carbon they hold to be released into the atmosphere. Cutting the trees and using the wood before they are killed, and then replacing them, the team notes, would make far more sense.

Explore further: Loss of African woodland may impact on climate, study shows

More information: First signs of carbon sink saturation in European forest biomass, Nature Climate Change (2013) DOI: 10.1038/nclimate1853

Abstract
European forests are seen as a clear example of vegetation rebound in the Northern Hemisphere; recovering in area and growing stock since the 1950s, after centuries of stock decline and deforestation. These regrowing forests have shown to be a persistent carbon sink, projected to continue for decades, however, there are early signs of saturation. Forest policies and management strategies need revision if we want to sustain the sink.

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Moebius
3.5 / 5 (8) Aug 19, 2013
Our activity is dumping billions of tons of carbon into the atmosphere every year. Hard to believe something is nearing sink saturation.
NikFromNYC
2 / 5 (24) Aug 19, 2013
"Europe is unique in that it's one of the few places on the planet that has more trees now than it did a century ago."

Climate alarm is *always* a mealy-mouthed dodge! James Hansen's last paper at NASA says coal is helping to moderate the greenhouse effect with smog but also is adding enough nitrogen to amplify fertilization:

"We suggest that the surge of fossil fuel use, mainly coal, since 2000 is a basic cause of the large increase of carbon uptake by the combined terrestrial and ocean carbon sinks. One mechanism by which fossil fuel emissions increase carbon uptake is by fertilizing the biosphere via provision of nutrients essential for tissue building, especially nitrogen, which plays a critical role in controlling net primary productivity and is limited in many ecosystems and field studies confirm a major role of nitrogen deposition, working in concert with CO2 fertilization, in causing a large increase in net primary productivity of temperate and boreal forests."
NikFromNYC
1.9 / 5 (23) Aug 19, 2013
Forests are finally recovering from 100s of years of pre-industrial wood burning blight and unfertilized agriculture *and* CO₂ starved ocean algae has "suffered" a whopping 40% boost in productivity:

"From the mid-Mesozoic, coccolithophores have been major calcium carbonate producers in the world's oceans, today accounting for about a third of the total marine CaCO3 production. Here, we present laboratory evidence that calcification and net primary production in the coccolithophore species Emiliania huxleyi are significantly increased by high CO2 partial pressures. Field evidence from the deep ocean is consistent with these laboratory conclusions, indicating that over the past 220 years there has been a 40% increase in average coccolith mass. Our findings show that coccolithophores are already responding and will probably continue to respond to rising atmospheric CO2 partial pressures...."

http://www.scienc...5874/336

Mugshot: http://postimg.or...zn62grp/
tadchem
3.5 / 5 (2) Aug 19, 2013
Yeah! Dynamic equilibria are like that. Study the logistic equation...
GSwift7
3.4 / 5 (11) Aug 19, 2013
The last time I looked it up, a natural forest without human intervention takes about 400 years to reach saturation after it is cleared by a forest fire. That's on average though, since different types of forests in different locations will vary. Saturation is the point at which mature trees start to crowd out smaller vegitation and the death and decay rate becomes equal to the rate of new growth.

Counter to intuition, a large forest fire can lock some of the carbon in the forest into the ground as char, which takes that carbon out of the active carbon cycle. If left undisturbed, most of that will even mineralize into polycabonates, which are stable for very long times.

So, with their forests returning to their mature states, they need to allow the natural cycle of wild fires do its job so that the forest can resume carbon uptake. The carbon released by the fire is irrelevant since it's technically still active in the cycle anyway.
scottfos
3.4 / 5 (5) Aug 19, 2013
Nik, do you mean this guy ted.com/talks/james_hansen_why_i_must_speak_out_about_climate_change.html? it's a long TED - 17 minutes - but i suggest you watch it. is he mealy mouthing climate alarmist dodger? and if so, why would you quote his paper?

your statements make me wonder....how in the world did earth *survive* before humans started burning fossil fuels!
VENDItardE
1.6 / 5 (14) Aug 19, 2013
fkn bullsh*t
EnricM
2.1 / 5 (10) Aug 20, 2013
The problem with replacing old forests is that they do play a key role towards species diversity and species conservation.
It does also play a role in flood and desertification protection and other roles not related directly to their carbon absorption.
On the other side I don't know if the study takes the soil into consideration.
shem
1 / 5 (3) Aug 20, 2013
It's new growth which uses CO2. If they want to make use of CO2, simply replace old growth with new growth. This is most economically done by sequestoring CO2 in furniture and buildings and planting new trees.

Paper has also done this in the US. While paper does not sequestor CO2 as long, demand for paper has diven forest growth.
GSwift7
2.3 / 5 (3) Aug 21, 2013
Paper has also done this in the US. While paper does not sequestor CO2 as long, demand for paper has diven forest growth


Paper is a big factor in certain parts of the US, such as the South East (where I live), but not the biggest reason that the US has largely been re-forested over the past couple hundred years.

The decline of small farms is the bigger reason. In places like New York State, you can find old farm houses and barns sitting in the middle of the woods all over the place, for example. I used to hike there, and it's not uncommon to find stone walls in the middle of old growth forest, where fields used to be. Now the small farms just cannon compete with the large industrial farms. That's what is happening in Europe too, which is why we see the story above.

It might surprise people to know that process started so long ago. It's happening in Asia now too, as their economy continues to move from agrarian to industrial.

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