I believe they cannot start with big trees and bushes because the there is not enough nutrients in the soil, so instead pioneer species pave the way for primary succession.
Baby jamison was born with Cystic Fibrosis (CF)
The answer is concrete laundry trays.
This is because as concrete trays ages with timeit becomes coarse and rugged due to water, soap and detergents. Their smoothness gradually fades with time, thus this makes it not as good regarding to health wise standards of living.
