Model-checking ecological state-transition graphs
Fig 1
State-and-transition models of the Borana vegetation pathways.
The states are embodied by illustrated boxes, and the transitions by arrows labelled by their main driving processes. (a) Before pastoralism, fire was the main driver of the rangeland dynamics. The combination of fire, wildlife herbivory and vegetation recruitment maintained the entire system in a loop between open canopy woodland and grassland. (b) The presence of cattle and the fire ban gave a competitive advantage to woody plants, inducing an irreversible bush encroachment. Concurrently, wildlife increasingly avoided the Borana zone because of the denser human and livestock populations. (Based on [21] with author’s permission).