Answer:
first food chain:
The Producer: the trees
The Primary Consumers: elephants
The Secondary Consumers: the cheetah
The Scavengers: the termites
The Decomposers or Detritivores: mushrooms
second food chain
The Producer: grass
The Primary Consumers: zebras
The Secondary Consumers: the hyena
The Scavengers: the vultures
The Decomposers or Detritivores: microorganisms
the food web:
The Producers - the trees and grass.
The Primary Consumers – the zebras and elephants.
The Secondary Consumers – the cheetah, hyena.
The Scavengers – the termites, vultures
The Decomposers or Detritivores – mushrooms microorganisms.
If the amount of primary Consumers increases, the number of producers would decrease and the number of other consumers would increase, but after a short time their number would also decrease and it causes immigrations.
Also, there's a nice picture I have found on a site;
