Sequence of communities that successively change in an area is called:

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  1. Sere
  2. Pioneer species
  3. Climax species
  4. Ecological succession

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Option 4 : Ecological succession
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The correct answer is Ecological succession

Explanation:

The sequence of communities that successively change in an area is referred to as ecological succession. Ecological succession is the process by which the structure of a biological community evolves over time. There are two main types: primary and secondary succession.

Primary Succession:

  • Occurs in an area where there were previously no living organisms and the soil had not yet formed, such as after a lava flow or on a new island created by volcanic activity.
  • The initial species that colonize such areas are called pioneer species. These species are typically hardy and capable of withstanding harsh conditions. An example of pioneer species are lichens and certain types of algae.
  • Over time, these pioneer species alter the environment (e.g., by breaking down rock into soil), making it more habitable for other species to move in and establish themselves.

Secondary Succession:

  • Occurs in areas where a community previously existed but has been disturbed or removed by events like fires, floods, or human activities, leaving the soil intact.
  • Because the soil is already present, secondary succession usually proceeds faster than primary succession.
  • The first plants to grow back might be fast-growing grasses and weeds which are then followed by more complex plants like shrubs and young trees.

​A sere refers to a series of stages or communities that follow one another in a specific sequence during ecological succession, from the initial colonization to the climax community. Each stage within this progression is known as a seral stage. For example, in the succession of a forest, the sere might include the stages from pioneer species to intermediate species to a mature forest community.

  • The community that is in near equilibrium with the environment is called a climax community.
  • The species that invade a bare area are called pioneer species. 
    • Lichens are the pioneer species on a bare area or Xerarch condition. 
    • Phytoplanktons are the pioneer species in Hydrarch succession.
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