Mature trees add more tissue each year - more than planting new tress.

articles on keep the trees we have and plant and care for the trees:

https://www.sciencenews.org/article/planting-trees-protect-forests-climate-change

https://www.sciencenews.org/article/trees-crops-agroforestry-climate-biodiversity

https://www.sciencenews.org/article/planting-trees-climate-change-carbon-capture-deforestation

https://www.sciencenews.org/article/tasking-trees-with-averting-climate-crisis-big-ask