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Correct me if I'm wrong, but I think it's a common misconception that trees store a really large amount of carbon, usually it is dwarved by the carbon associate

Correct me if I'm wrong, but I think it's a common misconception that trees store a really large amount of carbon, usually it is dwarved by the carbon associated with the soil where the trees grows. Over generations, in particular in a rainforest, enormous amounts of carbon are put into the soil, and burning down the forest doesn't just release the carbon from the trees, but many times that number from the soil. Regrow the trees, and you only recapture a fraction of what is released. I imagine you're going to get a similar effect from permafrost melting.

oh_sigh 10y ago
Yes - also, old growth forests/rainforests are mostly one-and-done carbon sinks. They grow, absorb a bunch of carbon, and then their growth rate drastically drops.
- greeneggs 10y ago
  Do you know this, or are you just giving your intuition? I tried a quick Google search to see if this is true, and they don't seem to agree. (However, they are mostly talking about individual trees, not whole forests.) A couple links: 1. "Traditionally, two conflicting viewpoints about tree growth have coexisted. One view was that after an initial increase in growth rate, trees would grow more slowly as they age. Another theory posits that growth rates should increase with increasing tree size. The study results support the latter, showing that in most cases growth rates increase as trees age. This was found to be true for 87 percent of the species reviewed. For the group of largest trees in the study, scientists observed this phenomenon in 97 percent of the species. This translates into a growth rate nearly three times faster for trees with a trunk diameter of 100 centimeters (39 inches) than for trees with a 50-centimeter (20-inch) diameter within a species." http://environment.yale.edu/yer/article/carbon-capture-tree-size-matters#gsc.tab=0 http://environment.yale.edu/yer/article/carbon-capture-tree-... 2. "A 2,000-year-old giant sequoia is just cranking out wood, said Steve Sillett, a professor at Humboldt State University in California who has conducted recent research on the big trees. Other long-lived trees like coast redwoods and Australia's Eucalyptus regnans also show an increase in wood production during old age, according to an article Sillett published in the journal Forest Ecology and Management." http://news.nationalgeographic.com/news/2012/12/121205-sequoia-redwoods-trees-old-national-park-science-environment/ http://news.nationalgeographic.com/news/2012/12/121205-sequo... 3. "This supposition is supported by the fact that we, like others (15), see no consistent evidence for changes in growth rates for individual trees during their lifetimes" http://www.pnas.org/content/102/51/18502.full.pdf http://www.pnas.org/content/102/51/18502.full.pdf
  - mturmon 10y ago
    Clearly - as you note - the individual-tree analysis in (3) [I did not read the others] is not relevant to the point raised by the comment you are addressing. (In turn, that comment/speculation itself is not really relevant to the point above it.) The above papers seem to be an attempt to answer the question, "Can't we just re-capture the carbon released from deforestation/logging by re-planting small trees in these areas," and the answer seems to be "not on a 1:1 basis".
  - Brakenshire 10y ago
    You almost feel that an old growth forest by definition does not increase its stock of carbon held in trees. Trees can't become denser and taller forever (although sequoias seem to give that a good go).
mturmon 10y ago
This is correct, even for Arctic regions. According to [1], net production of carbon in Alaskan Arctic regions is about 0.14 kg / meter-squared, per year. But soil content is about 14 kg / meter-squared. Crudely, that means 100 years of net carbon production would be sequestered in soil carbon. [1] http://www.biogeosciences.net/11/4271/2014/ http://www.biogeosciences.net/11/4271/2014/
- Brakenshire 10y ago
  Thanks for the link, very interesting.

oh_sigh 10y ago

Yes - also, old growth forests/rainforests are mostly one-and-done carbon sinks. They grow, absorb a bunch of carbon, and then their growth rate drastically drops.

greeneggs 10y ago
Do you know this, or are you just giving your intuition? I tried a quick Google search to see if this is true, and they don't seem to agree. (However, they are mostly talking about individual trees, not whole forests.) A couple links: 1. "Traditionally, two conflicting viewpoints about tree growth have coexisted. One view was that after an initial increase in growth rate, trees would grow more slowly as they age. Another theory posits that growth rates should increase with increasing tree size. The study results support the latter, showing that in most cases growth rates increase as trees age. This was found to be true for 87 percent of the species reviewed. For the group of largest trees in the study, scientists observed this phenomenon in 97 percent of the species. This translates into a growth rate nearly three times faster for trees with a trunk diameter of 100 centimeters (39 inches) than for trees with a 50-centimeter (20-inch) diameter within a species." http://environment.yale.edu/yer/article/carbon-capture-tree-size-matters#gsc.tab=0 http://environment.yale.edu/yer/article/carbon-capture-tree-... 2. "A 2,000-year-old giant sequoia is just cranking out wood, said Steve Sillett, a professor at Humboldt State University in California who has conducted recent research on the big trees. Other long-lived trees like coast redwoods and Australia's Eucalyptus regnans also show an increase in wood production during old age, according to an article Sillett published in the journal Forest Ecology and Management." http://news.nationalgeographic.com/news/2012/12/121205-sequoia-redwoods-trees-old-national-park-science-environment/ http://news.nationalgeographic.com/news/2012/12/121205-sequo... 3. "This supposition is supported by the fact that we, like others (15), see no consistent evidence for changes in growth rates for individual trees during their lifetimes" http://www.pnas.org/content/102/51/18502.full.pdf http://www.pnas.org/content/102/51/18502.full.pdf
- mturmon 10y ago
  Clearly - as you note - the individual-tree analysis in (3) [I did not read the others] is not relevant to the point raised by the comment you are addressing. (In turn, that comment/speculation itself is not really relevant to the point above it.) The above papers seem to be an attempt to answer the question, "Can't we just re-capture the carbon released from deforestation/logging by re-planting small trees in these areas," and the answer seems to be "not on a 1:1 basis".
- Brakenshire 10y ago
  You almost feel that an old growth forest by definition does not increase its stock of carbon held in trees. Trees can't become denser and taller forever (although sequoias seem to give that a good go).

mturmon 10y ago

This is correct, even for Arctic regions. According to [1], net production of carbon in Alaskan Arctic regions is about 0.14 kg / meter-squared, per year. But soil content is about 14 kg / meter-squared. Crudely, that means 100 years of net carbon production would be sequestered in soil carbon. [1] http://www.biogeosciences.net/11/4271/2014/ http://www.biogeosciences.net/11/4271/2014/

Brakenshire 10y ago
Thanks for the link, very interesting.