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In ecology, the pronounced changes in communities of the ecosystem due to natural calamities or human intervention are called disturbances. The physical structure of biotic and abiotic components is quickly altered by ecological disturbances.

The major examples of disturbances include natural disasters, insect outbreak, anthropogenic disturbances (human activities), and climate change.

The intermediate disturbance is the moderate disturbance that occurs in an ecosystem. It allows ecological succession, the adaption of organisms to disturbance, and cooperative living of all the species.

A high-level disturbance eliminates species, and a low-level disturbance dominates only one more tolerant species. The hypothesis states that moderate disturbance is part of a healthy ecosystem.

When fire stops in prairies, it undergoes ecological succession. Since plants were already in this region, secondary succession is most likely to occur. The prairies include climax community within 100 years. The high-level disturbance completely changed to low-level disturbance when prairies stop experiencing fire.

Therefore, the less tolerant species would be excluded from the community due to the dominancy of more competitive species. The low-level disturbance does not facilitate diversity in the community.