Question

Differentiate between autogenic and allogenic succession.

Answer 1

1. Autogenic succession occurs due to biotic factors present in an ecosystem.
2. Allogenic succession occurs due to abiotic factors present in an ecosystem.

Autogenic succession	Allogenic succession
It always occurs due to endogenous factors.	It is caused by exogenous factors.
Secondary succession begins with autogenic succession.	Primary succession begins with allogenic succession and slowly proceeds towards autogenic succession.
Example: accumulation of dead organic matter in the soil changes the nutrient composition of soil and microorganisms living in it. This is an example of autogenic succession.	Example: floods, forest fires, volcanic eruptions, and global warming change the ecosystem over time.