Alternative stable state theory predicts that diferent disturbance regimes may support contrasting ecosystem states under otherwise analogous environmental conditions. In fre-prone systems, this theory is often invoked to explain abrupt ecotones, especially when adjacent vegetation types have contrasting fammabilities and difering tolerances to pyric perturbation. Despite being well-documented in forest-savanna transitions, unambiguous examples of fre-driven alternate stable states (FDASS) in arid systems are rare. The current study examined whether fammable spinifex (Triodia spp.) grasslands and fre-sensitive waputi (Aluta maisonneuvei subsp. maisonneuvei) shrublands in Australia’s Gibson Desert represent FDASS. Specifcally, analyses of soil and topographic variables assessed whether environmental diferences explain habitat zonation. To determine whether diferent fammabilities of Aluta and Triodia systems may perpetuate alternative states via vegetationfre feedback processes, community-level fuelloads were quantifed to provide an indirect measure of fammability. To determine the propensity for fre to trigger ‘state-shifting’, community responses to a single high-severity fre were evaluated. Habitat segregation did not relate to between-site environmental diferences, and the fuel-load study indicated that the more pyrophytic community (Triodia grassland) is more fammable, and hence more likely to experience higher frequency frecycles. Fire was identifed as a potential vector of ‘state-change’, because although both systems regenerated well after fre, Triodia reproduced more prolifcally at a younger age than Aluta, and hence should tolerate shorter fre-return intervals. In the absence of between-community topographic and edaphic diferences, or herbivores that consume either plant, it is likely that Aluta shrublands and Triodia grasslands represent fre-mediated alternative equilibrium states.