An ecosystem that is not sustainable can break down when a natural disaster occurs. this can lead to organisms in the ecosystem either leaving the area or dying off. increased biodiversity results in a more sustainable ecosystem because — a) a greater number of plant species means that there is less barren land b) a greater variety of species present allows more organisms to adapt after changes occur c) the transition area between two ecosystems is narrower d) there are fewer species to be affected by environmental stresses