Answer:
They need to use energy from other tress to survive so that they can do basic functions, like absorbing nutrients from the ground, and growing back leaves. They don't have chlorophyll, so they need that energy to do the functions I mentioned above.
Explanation: Hope this helps!
Answer:
I know that Aerogel is the lightest metal in existence, but I don't think it would help much with your answer. I mean you can give it a try?
