Photosynthesis is pretty inefficient and trees release the CO2 when they rot, so they aren’t great for long term storage. At certain phases of growth, forests are actually carbon positive. DAC can bind carbon to rock or pump it deep underground where it will stay potentially forever(on any meaningful human timescale). You can also directly account for the tons of CO2 removed by DAC which makes it more used for carbon trading schemes that financially incentivize capture.
That's true, but they don't fix any more carbon after they're fully grown. I'm not against tree planting, but it's probably a bit oversold as a solution. Kelp probably presents a more interesting opportunity.
I know at least conifer trees are never "fully grown". I imagine it is the same for deciduous trees. Trees continue to add wood to there structure every year. You count the tree rings to know its age. A 500 year old redwood, cedar, or Douglas fir can be 15 or more feet in diameter. That is a lot of wood. Unlike what many people thought, studies have found that the volume of wood added to trees in a mature forest is similar to a young one.
