4 ms·

Reminds me of the question “what are trees made of?” (The answer to both questions is “mostly atmospheric CO2.”)

k__ 9y ago
Hehe, true. I once saw a documentary about "big animals" in the past. Like, why did we have giant spiders and insects while they have a rather simple respiratory system that doesn't scale very well. Because: trees! Somehow plants managed to create wood, which bound the C from CO2, but the rest of the biosphere didn't know what to make of the wood. So there were more and more trees and more and more C got removed from the atmosphere. A much bigger part of the atmosphere was O2 and so the insects could grow bigger. But in the end the fungi figured out how to make short work of wood and in turn released much of the C again into the atmosphere as CO2, so the animals shrunk again.
- Cd00d 9y ago
  I thought ants were what made short work of the wood. Something about formic acid? Do you know more - I need to reset my ignorance.
  - k__ 9y ago
    No sorry. Maybe it was both? The documentary just told about the fungi.
    - Cd00d 9y ago
      okay - thanks. Years ago someone told me a story of the ants saving us from a wood death, and I never checked it out, but recounted it just the other day. Fungi seems more reasonable on reflection.
- dandare 9y ago
  That is very interesting. Is it related to coal? Will the trees today nor form coal because they will be processed by fungi?
  - masklinn 9y ago
    > That is very interesting. Is it related to coal? Will the trees today nor form coal because they will be processed by fungi? No, coal has formed after fungi found how to break down lignin (lignite is usually "young" coal, having generally formed between the disparition and the dinosaurs and modern day, generally speaking the better the coal the older it is as coal is a metamorphic process, so given similar conditions time is the factor for the rock going through the grades), lignin isn't the only organic component even in carboniferous coals, and these coals have lignin-rich and lignin-poor epochs and locations. And peat lands exist today which perform the first "step" of coal formation. The trees today are unlikely to form coal because that first requires quickly putting the trees in anoxic conditions (e.g. acidic waters or low-permeability soils) over a sufficiently long time that good-sized layers can build up, then shifting those layers way down so they can be converted by heat and pressure over millions of years. Carboniferous had lots of low-lying forested wetlands and swamps which provided the vegetable matter in anoxic conditions, and the subduction zones of the forming pangea proceeded to shove much of it under (when both happened in the same place), that is why it's the source of so much coal. But few of our peatlands are in subduction zones, and even if they were it's unlikely we'd give them the time to accumulate and slide down for processing.
- ultratopo 9y ago
  Do you remember the name of the documentary?
  - k__ 9y ago
    No sorry, this was probably 10 years ago and in German.

k__ 9y ago

Hehe, true. I once saw a documentary about "big animals" in the past. Like, why did we have giant spiders and insects while they have a rather simple respiratory system that doesn't scale very well. Because: trees! Somehow plants managed to create wood, which bound the C from CO2, but the rest of the biosphere didn't know what to make of the wood. So there were more and more trees and more and more C got removed from the atmosphere. A much bigger part of the atmosphere was O2 and so the insects could grow bigger. But in the end the fungi figured out how to make short work of wood and in turn released much of the C again into the atmosphere as CO2, so the animals shrunk again.

Cd00d 9y ago
I thought ants were what made short work of the wood. Something about formic acid? Do you know more - I need to reset my ignorance.
- k__ 9y ago
  No sorry. Maybe it was both? The documentary just told about the fungi.
  - Cd00d 9y ago
    okay - thanks. Years ago someone told me a story of the ants saving us from a wood death, and I never checked it out, but recounted it just the other day. Fungi seems more reasonable on reflection.
dandare 9y ago
That is very interesting. Is it related to coal? Will the trees today nor form coal because they will be processed by fungi?
- masklinn 9y ago
  > That is very interesting. Is it related to coal? Will the trees today nor form coal because they will be processed by fungi? No, coal has formed after fungi found how to break down lignin (lignite is usually "young" coal, having generally formed between the disparition and the dinosaurs and modern day, generally speaking the better the coal the older it is as coal is a metamorphic process, so given similar conditions time is the factor for the rock going through the grades), lignin isn't the only organic component even in carboniferous coals, and these coals have lignin-rich and lignin-poor epochs and locations. And peat lands exist today which perform the first "step" of coal formation. The trees today are unlikely to form coal because that first requires quickly putting the trees in anoxic conditions (e.g. acidic waters or low-permeability soils) over a sufficiently long time that good-sized layers can build up, then shifting those layers way down so they can be converted by heat and pressure over millions of years. Carboniferous had lots of low-lying forested wetlands and swamps which provided the vegetable matter in anoxic conditions, and the subduction zones of the forming pangea proceeded to shove much of it under (when both happened in the same place), that is why it's the source of so much coal. But few of our peatlands are in subduction zones, and even if they were it's unlikely we'd give them the time to accumulate and slide down for processing.
ultratopo 9y ago
Do you remember the name of the documentary?
- k__ 9y ago
  No sorry, this was probably 10 years ago and in German.