A simulation model of the population dynamics of the branching coral Acropora palmata Effects of storm intensity and frequency

A stage-based model was developed to predict the effects of storm intensity and frequency on populations of the branching coral Acropora palmata. The data used to parameterize the model were obtained from an A. palmata population in the northern Florida Reef Tract that experienced three storms in 27 months. intensity is a significant factor influencing the survivorship of A. palmata populations. After a severe storm, A. palmata populations can be numerically dominated by fragments and crusts. The shift in biomass from units with high survivorship (i.e. colonies) to units with higher mortality probabilities (i.e. fragments and crusts) can affect the recovery and long-term survivorship of disturbed populations. However, the model suggests that A. palmata still can benefit from periodic storms. When sexual recruitment is limited or sporadic, storm fragmentation followed by fragment survivorship and growth may be the only mechanism available for A. palmata to propagate. frequency can also affect the survivorship of A. palmata. When storms occur at 15-year intervals, a slow increase in the abundance of colonies can take place after 10 consecutive storms. When storm frequency increases to 5 years, the abundance of colonies can increase five-fold after 10 storms. However, as storm frequency increases further (one storm every 2 years) a steady decline in the abundance of A. palmata colonies can occur.