Question

I have in pastasked this about ash, but apart from ash most fires - whether natural or fires in stoves - leave a bunch of charcoal as well. When I was sifting old compost last year, I could identify the layers where the fire pit contents were dumped in - but not by ash, as it really mostly dissolved and disappeared, but by charcoal (and also nails sadly). In those layers, there were chunks of charcoal as well as larger partly decomposed pieces of wood covered by charcoal. So, since no wildfire is perfect to the point of burning all organic matter perfectly, what happens to the charcoal after wildfires - or to the charcoal that is dumped with ashes to composts and gardens? Carbon is extremely chemically stable unless you set it on fire, so is there anything that can oxidize it in nature? If not, is the soil in places of common wildfires rich in pure carbon crystals from millennia of fires and regrowth? Short answer - not really. Charcoal as almost pure carbon is fairly inert, not readily available and can remain in the environment almost indefinitely. This is evidenced bycharcoal in rocksfrom theSilurian period(~440 million years ago). We also find evidence of forest fires in the form of charcoal in almost all time periods since this point. I've personally picked charcoal out of buried soils that is at about 2000 years old fromvolcanic eruptions- admittedly there the top layers might well have been sterilized by the heat of the pyroclastic flows, so not a perfect analogy. However we can identify domestic camp sites from Neanderthal and other early human species for the past ~160,000 years, mostly from ash and charcoal presence. Edited to add: in the case of biochar and similar products, the charcoal is used to act as a reservoir for the nutrients (charcoal is really good at absorbing thingsa laactivated charcoal), which can be taken up into the microstructure of the charcoal and released as the plant rootlets and/ormycorrhizaeinvade. The charcoal also provides a looseness to the soil allowing greater aeration, better drainage and allowing roots to penetrate to a greater depth. These all help plants to grow well.

Answer 1

Charcoal, which is mostly carbon, is a stable substance and does not readily oxidize in nature. It can remain in the environment for a long time and may accumulate in soils after wildfires. Charcoal can also be used in composts and gardens to improve soil quality.

Step-by-step explanation:

Charcoal, which is mostly carbon, is a fairly inert substance and does not readily undergo oxidation in nature. This means that it can remain in the environment for a long time. In places where there have been common wildfires, the soil may indeed be rich in pure carbon crystals from millennia of fires and regrowth. However, charcoal can also be used in composts and gardens, where it acts as a reservoir for nutrients and helps improve soil drainage and aeration.