2. Pioneers species alter the conditions to favor growth for the next group.
3. Primary succession: starts with bare rock (no soil), ends with climax community. Slow process because of the limiting amount of Nitrogen available (e.g., glacier retreating, beaches).
4. Secondary succession: starts with cleared land (soil present), ends with Climax community. Rapid process because soil nutrients already present; seed bank present (e.g. abandoned farm; natural disasters).
5. Lake succession: starts with algae, ends with meadow or forest as Climax community.