Hey woodworking fedi, how do I repair these in a way that does not cause trouble later on?

Currently they do not go all the way through but give it another 10 or 50 years and they likely will as the wood continues to shrink. So what do I need to do to make this thing usable now and repairable later?

@skye soundboard cracks are often fixed by use of a "bowtie" cleat glued across the interior side of the crack. The picture doesn't show perfectly, but are these cracks glue line separations rather than splits in the wood? It may be that a fix could be effected by cleaning the joints and re-gluing, but I'd seek professional advice first.