Figure 1.
Different coral species interact with each other and with two different types of algae. Mechanical disturbance affects the whole benthic community whereas high temperature triggers bleaching only in corals and herbivory affects only algae.
Figure 2.
Flow chart of important processes of an individual coral colony.
If recruit settling is successful, the coral colony enters its life-cycle. Within each iteration the temperature is checked, upon which it is decided if the colony will bleach or not. If it bleaches it can die or recover. In the next step the colony interacts with its neighborhood and if it does not die, it grows. Reproduction only takes place when the reproductive cycle allows it.
Figure 3.
The life-cycle of a virtual coral which applies for massive and branching groups.
1) A mature coral colony produces gametes. 2) Hermaphroditic brooders directly release planula larvae, colonies of hermaphroditic broadcasters release bundles of eggs and sperm, and gonochoric broadcasting species release eggs or sperm, respectively. In the latter two modes fertilization takes place in the water column and planulae develop. 3) The larva is distributed and settles randomly on the simulation area. If it settles on another living organism (6) it will die and is removed. A larva that recruits on unoccupied space develops (4 and 5) into a new colony. 7) Overgrowth, disturbance or bleaching can lead to the death of a coral colony, which is then removed from the simulation.
Table 1.
Linear extension rates of the implemented coral species.
Table 2.
Reproduction parameters of the different coral species.
Table 3.
Miscellaneous parameters of the implemented coral species.
Table 4.
The effect of interaction on growth of individual colonies or organisms.
Figure 4.
Mean relative cover (± SD) of the different coral species in relation to varying frequencies of major bleaching events without the influence of physical disturbances.
A clear shift in coral community structure can be observed when bleaching frequencies increase from 8–9 years.
Figure 5.
Effect of different frequencies of large (x-Axis) and small (y-Axis) disturbance events without the influence of major bleaching events.
The diameter of a pie chart denotes the percentage of the total benthic cover. Standard settings of mechanical disturbances, with smaller intensities occurring every 12 and larger ones every 60 months, are indicated by the gray frame. The colors represent benthic organisms as follows: P. lobata in blue, P. lutea in orange, A. muricata in red, P. damicronis in cyan and macroalgae in green.
Figure 6.
Mean relative cover (± SD) of the different coral species in relation to varying frequencies of major bleaching events at intermediate physical disturbance levels.
A clear shift in coral community structure can be observed when bleaching frequencies increase from 10–15 years.