After Hurricane Ian, I had to have the remains of some trees removed, including stumps. A few months ago, the location where my avocado tree was started sinking, creating a steep pit. I figured the remains of the ground up roots have decayed away and now the dirt is falling in. I have filled the hole level but I know it will continue sinking for quite some time and I may find it cheaper in the long term to get a load of sand in there instead of the garden soil I’ve been buying.
My question is: where did the mass of the roots go? I understand that the wood has been broken down by bugs and bacteria. But did they really carry away the wood physically? Or has the wood been turned into carbon dioxide by being digested and just floated away?
Some of both, and also, there is space in the wood structure that goes away. But I’m guessing mostly it decays into CO2.
Buried trees and roots can leave a lot of space where they used to be. Sink holes have occurred where trees and were buried to make housing developments. Sometimes with deadly results. A lot of it turns back into carbon, oxygen, and nitrogen one way or another. Some insects and larger animals may carry it away but it’s mainly being eaten by bacteria and broken down that way first, and that reduces it to it’s primary components.
A lot of the bulk of it is mechanical structures and water. If you powderize and dry the remaining root mass, it would probably fit into a small pail.
The rest goes to decay which mostly ends up as carbon dioxide or consumed or carried away by other organisms.