Imagine an earthworm that has no chaetae. how would the lack of chaetae affect movement of the earthworm?

The worm would be unable to burrow and dig through the soil. Chaetae are involved in the locomotion of the worm by giving the worm grip and tools to burrow through the soil.  Chaetae are made of chitin project from the body wall on each segment are arranged in 4 pairs and are sited on the ventral surface - two pairs of ventral chaetae are found just either side of the midventral line and two pairs are further out in the ventrolateral position (that is just ventral of the side of the worm).

it restores trees to areas where they once grew.