Good explanation Lee. Kirk Johnson
> From: Lee Frelich <[email protected]> > Reply-To: [email protected] > Date: Fri, 01 Jan 2010 09:57:39 -0600 > To: [email protected] > Subject: Re: [ENTS] Fwd: carbon storage > > Bob: > > I think they basically got the story correct: > 1. Old growth forests continue to soak up carbon for much longer than we > used to think > 2. However, they do not soak up carbon as fast as young-middle aged forests > 3. Old growth forests store a huge amount of carbon per acre, especially > in soil, and if harvested some of that will continue to leak out of the > soil for some time, thus negating the sequestration that occurs by the > new growth. > > Another point is that a substantial amount of carbon is emitted by > cutting down a tree, hauling it to the mill, making it into lumber, and > then transporting the lumber to a lumber yard and to a construction > site. This can vary from 25% to 100%+ of the amount of carbon in the > wood, depending on harvest methods and distance to the mill and to the > site where the wood is ultimately used, and type of transportation > used. The benefit of storing carbon in wood products is not as great as > some people would have us believe. However, making steel and concrete > also emits a lot of CO2, so that using wood as a building material may > under some circumstances lead to less total emissions relative to other > building materials (given that a building was going to be built anyway). > In the future steel and cement plants may be able to sequester the CO2 > coming from their smokestacks, which would throw the balance back in > favor of steel and concrete. > > Lee > > > Bob wrote: >> 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] <mailto:[email protected]>> >>> *Date:* December 31, 2009 12:03:44 PM EST >>> *To:* [email protected] >>> <mailto:[email protected]>, >>> [email protected] >>> <mailto:[email protected]> >>> *Cc:* Bob Leverett <[email protected] <mailto:[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 <mailto:[email protected]> >>>> *To:* [email protected] >>>> <mailto:[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: >>>>> ³Can 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 forests² >>>>> >>>>> -- >>>>> >>> >> -- >> Eastern Native Tree Society http://www.nativetreesociety.org >> Send email to [email protected] >> Visit this group at http://groups.google.com/group/entstrees?hl=en >> To unsubscribe send email to [email protected] > > -- > Eastern Native Tree Society http://www.nativetreesociety.org > Send email to [email protected] > Visit this group at http://groups.google.com/group/entstrees?hl=en > To unsubscribe send email to [email protected] -- Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected]
