You're just wrong about this. It's still possible to find large fallen American Chestnut trunks from the blight. Trees will increase their biomass, hence seque

You're just wrong about this. It's still possible to find large fallen American Chestnut trunks from the blight. Trees will increase their biomass, hence sequestered carbon, for decades, and if left where they fall, it very much depends on the tree. A poplar will be gone in a couple years, a sycamore/plane will substantially still be there in a cenury.