Genuinely a case where size matters, at least in terms of carbon sequestration.

More specifically in this case, primary forests (untouched by human activity) are more diverse than secondary forests. This matters not only in the context that flora and fauna diversity is something to value for its own sake, but also because diverse forests are more productive (accumulate biomass more rapidly) and more resilient/resistant to external shocks such as extreme weather events, invasive species introduction, etc. This matters because as climate crisis events escalate in frequency and intensity many of the ‘new forests’ being planted right now are going to be completely fucking bodied, whereas older forests have a much better chance of riding it out.