Primary succession occurs on
- A
Periodically flooded riparian surfaces (river floodplains, deltas) — wetland plants come first
- B
Recently disturbed soil-bearing surfaces (burned forests, plowed fields) — grasses come first
- Ccheck_circle
Newly exposed lifeless surfaces (bare rock, lava flows) — pioneer species like lichens come first
- D
Long-undisturbed mature ecosystems (old-growth forests, climax prairies) — shade species dominate
Explanation
Primary: starts from no soil. Secondary: existing soil after disturbance.