Ecology and the nutrient cycle

Ecosystem

• It is a habitat which has the community of organisms living in it.
• Population is the same kind of organisms living in a particular habitat.
• Community is the different populations living in a particular habitat.

Biotic environment

• It is the interaction between organisms of either the same species or different species mainly for food and shelter.
• The interaction can be classified in terms of:
  - predator-prey: one species feeds on another species.
  - commensalism: one species gains benefits from another species without causing any harm.
  - parasitism: one species gains benefits from another species with harm
  - mutualism: two different species are benefited from each other

Abiotic environment

• The abiotic environment are light, water availability, oxygen, humidity, pH level and others.

Nitrogen cycle

• Nitrogen is removed form the air by nitrogen-fixing bacteria and lightning.
• Nitrogen is returned to the air by denitrifying bacteria.

Conservation of ecosystems

• Destructive activities such as over-hunting and deforestation disrupt the delicate balance of ecosystems.