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I thought rainforest is carbon neutral. Every tree is oxidized back to carbon dioxide after death. How can it absorb more carbon, than release? What is the sink

by monort 12y ago

I thought rainforest is carbon neutral. Every tree is oxidized back to carbon dioxide after death. How can it absorb more carbon, than release? What is the sink?

rosser 12y ago
Yes, trees die and immediately sublimate. No, it turns out, decay is a long-term process, and much (most, even) of the carbon is taken up by the organisms that feed on that decay.
- monort 12y ago
  So, what happens when that organisms die? Carbon should be stored somewhere without contact with oxygen, for forest to be carbon absorber.
  - guard-of-terra 12y ago
    Swamps are good candidates for this (as opposed to forests)
  - rosser 12y ago
    So, what happens when that organisms die? Another organism feeds on its decay? Lather, rinse, repeat.
landryraccoon 12y ago
If the rainforest increases in size, then carbon is removed from the atmosphere. If the rainforest decreases in size, it is released. As you pointed out, if the rainforest is the same constant size, it doesn't matter if a tree is oxidized after it dies - that means a new tree replaced it. The steady state is that the rainforest is a constant size. It is constantly absorbing and releasing carbon dioxide, but they must sum to zero if the size of the forest is constant.
crpatino 12y ago
A sink does not have to be an "ultimate sink", you can think of it as a temporary storage subsystem. Individual trees take carbon from the atmosphere, put it into their body mass, and release it years/decades later on their eventual death. As others have pointed out, a "steady state" forest would be carbon neutral. In any given year all the surviving trees add as much body mass as that of the fewer dying trees. However, steady state is usually not how things work out in practice. AFAIK, most years forest are carbon negative - slowly building up wood mass - and then there are specific events that make for big releases of carbon (big fires, blight that affects multiple trees, etc). Not sure if you can say that evens out to neutral in longer time frames. The problem in Brazil seems to be that illegal loggers are much more efficient than isolated release events for cutting down trees, so the normal tendency to sequester carbon is being overwhelmed. The "sink" in those terms gets turned into a "source". Not that new carbon atoms are getting created, but it's more like the buffer has now a tendency to grow smaller instead of bigger over time. btw. I don't understand why the down votes, so +1.
abandonliberty 12y ago
Canadian here. Worked for the forestry service 10 years ago on a team building out software to measure forestry carbon impact in a time before our elected leaders strove to imitate the conservative south. (Broke our national census, fired the scientists, chilled various debates, made it harder to vote, pursued a punitive approach to crime and drugs, etc. . . . but I digress[0]) Your assumptions are the same as we had in our published model. In an organization that wanted to earn money by cutting trees, we considered it a source of carbon we had to offset. Once the trees were cut, we assumed it was released. [0] this is a 5 minute google search: http://www.leadnow.ca/elections-act/ http://www.leadnow.ca/elections-act/ Though our Conservative press may try to convince you our failure to get a seat on the UN security council doesn't imply our international reputation is eroding, their figures still show our tourism is down a third from 2005-2013, our immigration is down/flat, and we're half as likely to be Google searched. http://www.macleans.ca/news/world/has-harper-hurt-canadas-position-in-the-world/ http://www.macleans.ca/news/world/has-harper-hurt-canadas-po.... On top of that, Nader has called us out: "We used to look to Canada to hold up a higher standard. There was a propensity to wage peace and engage in peacemaking — I'm sorry to see this Conservative government mimic the U.S. policy of militarization," he said. http://www.huffingtonpost.ca/2015/02/19/ralph-nader-stephen-harp_n_6717824.html http://www.huffingtonpost.ca/2015/02/19/ralph-nader-stephen-...? http://www.harperscrimes.ca/ http://www.harperscrimes.ca/

by monort 12y ago

I thought rainforest is carbon neutral. Every tree is oxidized back to carbon dioxide after death. How can it absorb more carbon, than release? What is the sink?

rosser 12y ago

Yes, trees die and immediately sublimate. No, it turns out, decay is a long-term process, and much (most, even) of the carbon is taken up by the organisms that feed on that decay.

monort 12y ago
So, what happens when that organisms die? Carbon should be stored somewhere without contact with oxygen, for forest to be carbon absorber.
- guard-of-terra 12y ago
  Swamps are good candidates for this (as opposed to forests)
- rosser 12y ago
  So, what happens when that organisms die? Another organism feeds on its decay? Lather, rinse, repeat.

landryraccoon 12y ago

If the rainforest increases in size, then carbon is removed from the atmosphere. If the rainforest decreases in size, it is released. As you pointed out, if the rainforest is the same constant size, it doesn't matter if a tree is oxidized after it dies - that means a new tree replaced it. The steady state is that the rainforest is a constant size. It is constantly absorbing and releasing carbon dioxide, but they must sum to zero if the size of the forest is constant.

crpatino 12y ago

A sink does not have to be an "ultimate sink", you can think of it as a temporary storage subsystem. Individual trees take carbon from the atmosphere, put it into their body mass, and release it years/decades later on their eventual death. As others have pointed out, a "steady state" forest would be carbon neutral. In any given year all the surviving trees add as much body mass as that of the fewer dying trees. However, steady state is usually not how things work out in practice. AFAIK, most years forest are carbon negative - slowly building up wood mass - and then there are specific events that make for big releases of carbon (big fires, blight that affects multiple trees, etc). Not sure if you can say that evens out to neutral in longer time frames. The problem in Brazil seems to be that illegal loggers are much more efficient than isolated release events for cutting down trees, so the normal tendency to sequester carbon is being overwhelmed. The "sink" in those terms gets turned into a "source". Not that new carbon atoms are getting created, but it's more like the buffer has now a tendency to grow smaller instead of bigger over time. btw. I don't understand why the down votes, so +1.

abandonliberty 12y ago

Canadian here. Worked for the forestry service 10 years ago on a team building out software to measure forestry carbon impact in a time before our elected leaders strove to imitate the conservative south. (Broke our national census, fired the scientists, chilled various debates, made it harder to vote, pursued a punitive approach to crime and drugs, etc. . . . but I digress[0]) Your assumptions are the same as we had in our published model. In an organization that wanted to earn money by cutting trees, we considered it a source of carbon we had to offset. Once the trees were cut, we assumed it was released. [0] this is a 5 minute google search: http://www.leadnow.ca/elections-act/ http://www.leadnow.ca/elections-act/ Though our Conservative press may try to convince you our failure to get a seat on the UN security council doesn't imply our international reputation is eroding, their figures still show our tourism is down a third from 2005-2013, our immigration is down/flat, and we're half as likely to be Google searched. http://www.macleans.ca/news/world/has-harper-hurt-canadas-position-in-the-world/ http://www.macleans.ca/news/world/has-harper-hurt-canadas-po.... On top of that, Nader has called us out: "We used to look to Canada to hold up a higher standard. There was a propensity to wage peace and engage in peacemaking — I'm sorry to see this Conservative government mimic the U.S. policy of militarization," he said. http://www.huffingtonpost.ca/2015/02/19/ralph-nader-stephen-harp_n_6717824.html http://www.huffingtonpost.ca/2015/02/19/ralph-nader-stephen-...? http://www.harperscrimes.ca/ http://www.harperscrimes.ca/