Only a fraction of all art that was ever created survives to this day. Naturally, large structures or images in stone have a better chance at survival. It is very hard to preserve wooden items for extended amounts of time, as they deteriorate rapidly unless kept in a well protected environment.
If a wooden sculpture is left outside it will most likely be destroyed by the elements after not too long. Attacked by fungi and bugs, battered by sun, rain and perhaps snow… there is little chance of its survival.
In contrast, some art has survived for hundreds or even thousands of years without much human maintenance.
The caves of Lascaux are the oldest example of graffiti/wall art (around 17,000 years old) and still exist because of the unique preserving environment of the caves. In comparison, the oldest pyramid in Egypt is ‘only’ approximately 4600 years old.
Many structures that survive to this day originally had a function of a monument, tomb, grave or burial site.
They are preserved because they were built very solidly, and partially because of certain climate factors that functioned as preserving agents.
To preserve your art depends in a great deal on how you see your art. If you want a tangible piece of art to survive, you could create a solid (religious) structure and decorate it with your art. Build this structure in a protective environment, far away from sea levels that can rise, arctic ice that can cover it, hurricanes or tornadoes that can destroy it. Maybe your creation will survive for a while (but you can’t ever say for sure).
I think there is a better way to do it, even though it erases your ego from the equation:
Teach your art.
Your legacy can live on for much longer than any tangible object that you made. People won’t necessarily name you as their inspiration in 300 or 3000 years but the inception of the idea ultimately has its roots in you.
The art that was given from generation to generation by inspiring people throughout history is where preservation happens. Don’t rely on a museum to value your art and preserve it, take it into your own hands.
Teach your art rather than trying to preserve tangible things that will deteriorate once you stop being around to protect them.