The term "living tree experiment" doesn't refer to a specific, well-known experiment. It's possible you're thinking of something else or have a misunderstanding.

To help me understand what you're asking, please provide more context or information:

* What is the purpose of the experiment? Is it about tree growth, environmental impact, or something else entirely?

* Where did you hear about this experiment? Was it in a book, documentary, or online?

* Can you remember any details about the experiment? Were there specific trees involved, a specific location, or a specific time period?

With more information, I can help you find the answer you're looking for.