Cyclical succession occurs when repeating environmental changes shift community composition without progressing permanently toward one stable endpoint or climax state.
Cyclical succession occurs when recurring disturbance repeatedly shifts a community through a predictable sequence without a single permanent endpoint.
Fire, flooding, grazing or seasonal conditions reset some species while survivors and propagules restart the pathway. Frequency and intensity set the cycle.
Compare disturbance interval with species life histories before predicting the recurring community.; separate state, pressure, control loop and time
A grassland burned every few years returns to fire-tolerant herbs rather than developing into forest. This gives a concrete prediction from the stated ecosystem.
A cycle is not random change; it requires a recurring driver and repeatable response. Interpret the result within the stated model and evidence limits.
HL D4.2 is the long-term change story. Succession begins after new habitat or disturbance, pioneer species modify conditions, primary succession builds soil and complexity, and some systems repeat cycles or are held before climax by disturbance.
HL succession questions focus on community pathways over time. The answer starts from the initial condition, shows how species modify abiotic conditions and interactions, and identifies whether the pathway is primary, cyclical, climax, or arrested by repeated disturbance.