Nature and Social Environment

Environment is our basic life support system. It provides the air we breathe, the water we drink, the food we eat and the land where we live.

The place, people, things and nature that surround any living organism is called the environment. It is a combination of natural and human made phenomena. Human beings modify the natural environment.

Ecology: Ecology is the study of organisms, the environment and how the organisms interact with each other and their environment.

Ecosystem:   An ecosystem is a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life. It contains Biotic as well as Abiotic components.

Every factor in an ecosystem depends on every other factor, either directly or indirectly. Ecosystems can be very large or very small.

Types of Ecosystem:

  1. Terrestrial Ecosystem
  2. Aquatic Ecosystem

Terrestrial Ecosystem

  • These are land based ecosystems.
  • Forest ecosystem, Grassland ecosystem, Tundra ecosystem, Desert ecosystem are example

Aquatic Ecosystem

  • Aquatic ecosystems are ecosystems that are present in a body of water.
  • Freshwater ecosystem (includes lakes, ponds, rivers, streams and wetlands); Marine ecosystem (includes seas and oceans, these have a more substantial salt content)

Biotic Components: Biotic components are living factors of an ecosystem. A few examples of biotic components include bacteria, animals, birds, fungi, plants, etc.

Based on nutrition biotic components are categorized as:

  1. Autotroph: An autotroph is an organism that can produce its own food using light, water, carbon dioxide, or other chemicals. Because autotrophs produce their own food, they are sometimes called producers.
  2. Heterotroph: Heterotrophs are organisms that depend on other organisms for food. They are also called consumers.
    1. Primary consumers: They rely on producers for food (herbivores).
    2. Secondary consumers: They depend on primary consumers for energy (carnivore or an omnivore).
    3. Tertiary consumers: They depend on secondary consumers for food (omnivore).
    4. Quaternary consumers: They depend on tertiary consumers.

 3. Decomposers: They directly thrive on the dead and decaying organic matter.  Decomposers are essential for the ecosystem as they help in recycling nutrients to be reused by plants  (saprophytes such as fungi and bacteria)