Which term describes the sequential replacement of species in an ecosystem after a disturbance?

Which term describes the sequential replacement of species in an ecosystem after a disturbance?

• A. Succession
• B. Species-Specific Relationship
• C. Symbiosis
• D. Sessile

Answer: (A)

Succession describes how the species makeup of an ecosystem changes in a sequence after a disturbance. Right after a disturbance, pioneer species able to tolerate harsh conditions begin to colonize, and their activities modify the environment—soil formation, nutrient availability, and shade—so other species can establish. Over time, a series of communities replaces the previous one until the system reaches a more stable state, sometimes called a climax community, or until a new disturbance resets the process. In marine contexts, succession can occur on bare substrata after storms or bleaching events, progressing from simple, fast-growing organisms to more complex communities. Distinguishing primary succession (on completely new, bare substrate with no soil) from secondary succession (where soil and some organisms remain) helps explain how fast or slow the replacement happens. The other terms don’t describe this temporal change in community composition: a species-specific relationship is about particular interactions between two species, symbiosis is a mutual or beneficial association, and sessile simply means non-motile.

Succession describes how the species makeup of an ecosystem changes in a sequence after a disturbance. Right after a disturbance, pioneer species able to tolerate harsh conditions begin to colonize, and their activities modify the environment—soil formation, nutrient availability, and shade—so other species can establish. Over time, a series of communities replaces the previous one until the system reaches a more stable state, sometimes called a climax community, or until a new disturbance resets the process. In marine contexts, succession can occur on bare substrata after storms or bleaching events, progressing from simple, fast-growing organisms to more complex communities. Distinguishing primary succession (on completely new, bare substrate with no soil) from secondary succession (where soil and some organisms remain) helps explain how fast or slow the replacement happens. The other terms don’t describe this temporal change in community composition: a species-specific relationship is about particular interactions between two species, symbiosis is a mutual or beneficial association, and sessile simply means non-motile.