In this scene, even Pollen needs help.  Pollen is trying to save the earth from a deadly asteroid hit.  The ring is having trouble functioning because of an electrical storm which has surrounded Pollen.  Pollen uses the tall trees, (The same trees he earlier saved from the lumberjack’s saws) as lightning rods.  Once the trees take the electrical storm away from Pollen the ring is able to fully function and protect the earth from the asteroid. 

It was the trees that helped save the earth.