Alternative state transition control by regulating the spatial arrangement of organisms using a lattice model

Abstract

Abstract Ecological systems can exist under multiple stable states for a specific set of environmental conditions. Perturbations can shift ecosystems to alternative stable states, and these changes are difficult to reverse. This is a concept known as hysteresis. Current management methods for system recovery require considerable effort. A model for system recovery that requires small changes in a target community would be of high value for ecosystem restoration. In this study, we focused on rocky reefs that exhibit two alternative stable states: one dominated by macroalgae and another dominated by sea urchins and crustose coralline algae. Community recovery requires a state shift. To better understand the state shift, we simulated the ecosystem using a lattice model incorporating local interactions, rather than equations representing homogenized spaces. Using spatial information and simulating conditions in the target ecosystem, we concluded that a shift to an alternative stable state is possible by adjusting the spatial arrangement of the organisms. These results indicate that spatial arrangements are significant in systems exhibiting hysteresis and that the spatial manipulation of organisms may be useful for ecosystem management and restoration.

Keywords

• alternative state
• hysteresis
• lattice model
• local interaction
• spatial pattern
• state shift