VPE 511: Environment and Environmental Hygiene (2+1)

CONSUMERS

• Organisms get their food by feeding on other organisms or organic matter. They are called heterotrophs.
• Primary consumers: Herbivores (or) Plant enters derive their nutrition directly from plants. e.g. Rabbit, Cattle, Elephant, Camel, Insect, Deer, etc.
• Secondary consumers: They are carnivores deriving their energy from herbivores Example: Frog and small Bird.
• Tertiary consumers: They are also carnivores that feed on other carnivores. Examples are snake, Big fish, Fox, Eagle, Tiger, Lion and Wolf.
• Omnivores: They feed on both plants and animals. Example- Man, Rat, Birds and Fox.
• Detrivores: They feed on dead organisms and wastes. Examples are Beetles, Termites, Ants, Crabs and Earthworms.

Decomposers

• They are the heterotrophs (e.g. Bacteria and fungi) acting upon faecal matters, exudates and dead bodies. They perform on invaluable service in the ecosystem by decomposing the above organic matter and make it available for reuse.

ECOSYSTEM STRUCTURE AND FUNCTION

STRUCTURE OF NATURAL ECOSYSTEM