The tropical hardwood hammock on Marco Island in Southwestern Florida owes its existence to garbage. Known as Otter Mound, this Calusa midden was used from 700 AD to 1200 AD as a dump for shells. Over the course of five or six hundred years the Calusa managed to eat enough whelk and oyster to raise several islands out of the water.
This area of Florida is pretty low-lying and wet, with a tendency to flood. The shell mounds built by the Calusa formed high-ground perches that were perfect habitats for tropical hardwoods.
If you are a birder, or if you are particularly in love with tropical hardwoods, you will be thankful that the Calusa created as much garbage as they did. This is what interests me: here is a landfill that is beneficial to the environment.
Perhaps the reason the Calusa shell mound never incurred the same bad name that our modern landfills seem to have attracted is that its contents were homogenous and unrefined: shells, shells, and more shells.
Did the piles of shells ruin some other habitat? Probably. But the shell piles proved to be useful for something else. I’m sure our modern day garbage piles are useful for some form of life, but it might behoove us to ask how nature will use our materially diverse mounds.
I have no idea whether the Floridian ecosystem is better or worse off because of the tropical hardwood hammocks that grow on the shell piles made by the Calusa. A lot of folks think the tropical hardwoods are the best thing that ever happened to Florida.
The news isn’t all good though: some people say that Ponce de Leon landed at the shell mounds, bringing with him the demise of the Calusa people, because he thought the ridges they formed indicated the Fountain of Youth. Hopefully no one will mistake our garbage for a mystical source of life-everlasting.