Does planting additional trees in plundered forests add value to CO2 sequestration?

Yes, of course, because usually very specific valuable tree species and especially the largest, most valuable and oldest trees have been felled and plundered. 50% of the biomass of a forest is concentrated in only 5% of the trees. Moreover, these tree species are almost completely absent from the ecosystem. By replacing exactly these tree species, we selectively enrich the biodiversity and strengthen the forest ecosystem from within. This is what ecologists call enrichment planting. For only if maximum species diversity prevails the forest will be able to withstand the effects of the climate crisis. A study from Panama in 2009 is very helpful here, as it attests to the very high CO₂ effect of enrichment planting: https://www.ecologyandsociety.org/vol14/iss1/art31/