Which ecological concept describes the orderly progression of communities in an ecosystem over time?

• A. Migration
• B. Predation
• C. Succession
• D. Mutation

Answer: (C)

Succession is the gradual, orderly change in the species composition and structure of an ecosystem over time, as communities build soil, create habitats, and shift which species dominate. It begins with pioneer species that can tolerate harsh conditions and start the soil-building process. Over time, the environment changes—soil depth and nutrients increase, light levels change, and species interactions reshape the community—so different plants and animals become established. This continues through intermediate stages until a relatively stable assemblage, often called a climax community, emerges. In forestry or wildlife contexts, you can see primary succession where barren ground becomes forest starting from bare rock, or secondary succession after a disturbance like fire or logging, where soil and some seeds remain and recovery begins more quickly. That step-by-step, predictable progression is what this concept captures. Migration, predation, and mutation are important ecological processes too, but they describe movement, interactions, or genetic change, not the long-term, orderly change in whole communities over time.