I saw a documentary some years ago, and I think it was on Discovery channel. Things I remember; some balloon creatures who was the planet's version of trees. They were like giant balloons with attached with a thick cable instead of a tree trunk. At the bottom there was some creatures eating on their roots.

Artificial life created on a computer, just a small segment.

A planet with life based on silicon. It was a fascinating but also boring planet where the organisms looked like short trees made of crystal. They reproduced with the help of the wind, now and then a very powerful storm would shatter the trees and spread them, and the fragments would grow up to new trees.

It's not impossible that I'm including elements from more than one documentary, but the way I remember it, they were all in the same program.

Anyone who remembers?

It was actually called "Alien Planet" & it was in 3 episodes - it may actually have been shown on one of the National Geographic Channels.