Lee
Are you up on the research identified below, and if so, any
thoughts you'd be willing to share?
Bob
Sent from my iPhone
Begin forwarded message:
> From: Mike Ryan <[email protected]>
> Date: December 31, 2009 12:03:44 PM EST
> To: [email protected],
> [email protected]
> Cc: Bob Leverett <[email protected]>
> Subject: Re: carbon storage
>
> Re: Science or conventional 'wisdom' from people who cut down trees
> for a living?:
>
> "...findings lay to rest the hoary notion that old-growth forests
> are worthless in the fight against global warming. On the contrary,
> they are an essential part of the struggle."
> "Plants take in CO2 and harness the energy of the sun to drive the
> chemical reaction that melds carbon with water, producing the
> substance of stem and leaf and releasing oxygen. When darkness or
> drought bring this process of photosynthesis to a halt, plants
> respire, just as humans do. That is, plants breathe in oxygen and
> exhale CO2. But over the long life span of trees in an undisturbed
> forest, huge reservoirs of carbon are stored for great stretches of
> time in the organic matter in soil as well as in living wood.
>
> People who cut down trees for a living tend to measure their value
> in dollars and cents. Traditionally, the timber industry has seen
> mature forests, with massive trees left standing and big logs
> rotting on the ground, as examples of waste; replanted clear-cuts,
> by contrast, represent an ideal of economic productivity. Now global
> warming has forced foresters to address the impact of logging on the
> flow of carbon between forests and the atmosphere, and many in the
> industry have insisted that stands of young, fast-growing trees
> capture carbon more efficiently than do older forests. Using a
> recently developed technology called the eddy covariance method-more
> commonly known as eddy flux ; Law and her colleagues are showing
> that those assumptions are wrong.
>
> It turns out that forests hundreds of years old can continue to
> actively absorb carbon, holding great quantities in storage.
> Resprouting clear-cuts, on the other hand, often emit carbon for
> years, despite the rapid growth rate of young trees. This is because
> decomposer microbes in the forest soil, which release CO2 as they
> break down dead branches and roots, work more quickly after a stand
> is logged. On the dry eastern face of the Cascades, for example,
> where trees grow slowly, a replanted clear-cut gives off more CO2
> than it absorbs for as much as 20 years. "That's a long time," Law
> observes, "during which microbes respiring in the soil, rather than
> trees photosynthesizing aboveground, dominate the carbon balance."
>
> Eddy flux measurement is one of Law's most crucial tools, enabling
> her to track the exchange of CO2 and water vapor between forest and
> air over large swaths of landscape, and at a level of detail that's
> never before been possible. The automated gas analyzers mounted on
> the eddy flux tower we're standing on measure CO2 concentrations 20
> times per second. Meanwhile a sonic anemometer, a three-pronged
> device that resembles a robotic claw, tracks wind speed and
> direction. The combination of these two data sets reveals the
> shifting flow of carbon in and out of a forest, day or night, winter
> or summer. Law notes with pride that all the technology at this
> research site is powered by photovoltaic panels.
>
> Other tools provide Law with additional insights into the flow of
> carbon through the intricate pathways of the forest. To photograph
> root growth, she slides a remote-controlled camera into a clear tube
> sunk belowground at a tree's base. Set on the forest floor are
> instrument-laden cylinders that hum to life every five minutes,
> lower themselves like miniature flying saucers, settle onto a patch
> of earth, and record the amount of carbon coming out of the soil.
>
> Law's data show that this 90-year-old forest is, in fact, at the
> peak of its ability to absorb carbon. The uptake of carbon by
> ponderosa pines increases gradually, then reaches a plateau at some
> point between 50 years and 90 years. Once this plateau is reached,
> the trees and the soil will together continue to form a rich bank of
> stored carbon that cannot be equaled by any newly sprouted stand.
> During her work in California and the Pacific Northwest, she's found
> forests as old as 800 years that continue to absorb more carbon than
> they release.
>
> Across forest types globally," Law says, "we find that the amount of
> carbon stored is high in older forests, and that live carbon [the
> carbon in living wood] continues to accumulate for centuries."
> AmeriFlux's findings are now publicly available online, and climate
> modelers are beginning to use the data to forecast the ways forest
> growth-or forest loss-could affect climate. Such models are used in
> simulations by the Intergovernmental Panel on Climate Change, whose
> authoritative reports shape climate policies worldwide.
>
> But these findings are news to the foresters I know. All of them
> remember, from college textbooks, a graph of tree growth that shows
> young trees bulking up rapidly over the first few decades of their
> lives, reaching a peak at 60 years to 70 years. After that, growth
> rates drop off. This pattern, which indicates that the most
> profitable point at which to harvest timber comes before the trees
> reach a century of growth, is deeply ingrained forestry
> wisdom...ignores the importance of the large amounts of carbon held
> in the living wood and fertile soil of old forests. When such stands
> are cut, about a third of the carbon is captured in marketable
> timber; the rest is rapidly released into the atmosphere. Like most
> foresters, Keye appears unaware of recent studies by Law, Wofsy, and
> their colleagues. Eddy flux measurement, supplemented by careful
> accounting of the carbon absorbed and released from leaves, the live
> roots burgeoning beneath the soil, and the rotting detritus of the
> forest floor, reflects the life of forests in far greater detail
> than traditional forestry analyses, which are based on measuring
> only those trees that are large enough to produce marketable timber.
>
>
> Source: Natural Resources Defense Council, 2008; Sharon Levy, 'The
> Giving Trees'
>
>> ----- Original Message -----
>> From: Charlie Thompson
>> To: [email protected]
>> Sent: Wednesday, December 30, 2009 3:47 PM
>> Subject: Re: carbon storage
>>
>> To answer, I need answers to these questions:
>>
>> 1) What general forest type?
>> 2) Does "stored" include all carbon pools?
>> [The answer to the general forest type question will provide the
>> age/ stage brackets for defining "late successional" and "old-
>> growth".]
>>
>> Charlie
>>
>> On Dec 30, 2009, at 1:05 PM, Bill Logue wrote:
>>
>>> Fred Heyes has asked if anyone knows the answers to the questions
>>> below:
>>> “Can someone tell me with reasonable accuracy
>>> how much carbon is stored per year per acre in late successional
>>> how much carbon is stored per year per acre in old growth forests”
>>>
>>> --
>>>
>
--
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