Question

Occurrence of relatively definite sequence of communities over a period of time in the same area is known as

• A. Change in biodiversity
• B. Ecosystem degradation
• C. Ecological succession
• D. Economic succession

Answer 1

The correct option is C Ecological succession

The standard definition of ecological succession is- The occurrence of a relatively definite sequence of communities over a period of time in the same area. It is characterized by certain interesting ecological features-

• It is directional and orderly. Therefore, it is possible to predict possible community compositions in the future.
• It occurs due to modification of the environment by the community itself. For example, fungus first colonizes bare rock. This fungus community begins to derive its nutrients from that rock, thereby dissolving it over time. It eventually leads to the formation of a thin layer of soil. This allows other species of plants to colonize the area, and they replace the fungus community.
  

• It culminates in a stabilized ecosystem. By stabilized, it means the ecosystem has a single dominant species, maximum possible species diversity, high biomass, and low annual yield. (Fun fact: The low annual yield is because the community is in equilibrium with itself and with the environment. Therefore, the energy produced by the ecosystem is consumed within itself. Little is left as surplus).

So, the correct answer is 'Ecological succession'.