When someone died in the town, their corpse was buried in the cemetery. When buried, they would have a plant growing on top of them as the corpses were excellent sources of nutrients for the tree.
Once a tree was large enough, which usually took over half a century or so, they were cut down to make for timber or whatever else was required of them.
The grave was then dug out to take all of the remaining bones out of the grave to use for whatever they could be used for, from fertilizers to making tools.
As such, there was a consistent cycle of corpses going in and out of the cemetery with its various uses. That was how it was set up from the beginning of the town's formation.
