Question

How can erosion be both constructive and destructive?

Answer 1

Erosion can destroy things that were already there and burn them.
But the lava that cools down can form new things. It can help plants grow from the cracks.

(HOPE THIS WAS HELPFUL)

Answer 2

Well, erosion can be destructive because it could carry soil, or sand, or rock, or whatever away from a place and destruct landforms... but it is constructive because when it moves that stuff, it puts it in a new place, slowly making new landforms.