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Ecosystems — BIOLOGY STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYEcosystems5 Marks
Question
  1. What is meant by ecological succession? How does it occur? Explain.
  2. Differentiate between Primary and Secondary succession.
✓

Answer

  1. The gradual and fairly predictable change in the species composition of a given area = 1. During succession some species colonise an area and their populations become more numerous, where as population of other species decline and even disappear = 1 + 1 = 2.
  2.  
 
Primary Succession
Secondary Succession
1.
It occurs in an area which has been bare from the beginning.
It occurs in an area which has been denuded recently.
2.
Soil is absent at the time of beginning of primary succession.
Soil is present in the area where secondary succession begins.
3.
Takes a long time for completion.
Takes less time for completion.

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