It's not a terrible solution, but you need specific trees of specific thicknesses for it to be possible at all (and these aren't always the same trees best suit

It's not a terrible solution, but you need specific trees of specific thicknesses for it to be possible at all (and these aren't always the same trees best suited for rapid growth). Selecting the most carbon-intensive plants and then turning them into biochar is probably better for long-term sequestration.