Complex sentence: As trees and brush grow larger the plants die out, but the seeds remain viable in the soil seed bank for many years; when a new fire or other disturbance occurs that opens up the ground to light again, the seeds germinate.
Split into simpler sentences: As trees and brush grow larger the plants die out, but the seeds remain viable in the soil seed bank for many years. When a new fire or other disturbance occurs that opens up the ground to light again, the seeds germinate.