Climate change redistributes and broadens the potential range of buffel grass ( <i>Cenchrus ciliaris</i> ) across Australia

<jats:p>Buffel grass (&lt;i&gt;Cenchrus ciliaris&lt;/i&gt;) is a perennial C4 grass introduced widely across global drylands for pasture production and soil stabilisation. In Australia, it spreads beyond plantings, reduces native biodiversity, alters fire regimes and hydrology, and threatens cultural values and Aboriginal Peoples’ connections to Country. Its potential national distribution remains poorly resolved, which constrains risk assessment and management. We developed an ensemble species distribution model from 8,232 occurrence records and nine climatic, edaphic, topographic, vegetation, and anthropogenic predictors at 5-km resolution, estimating current relative range probability and projecting changes under future climates for 2061–2080. Under current conditions, 32% of mainland Australia (2,405,610 km2) had moderate-to-high relative range probability (moderate: 0.33 to &lt; 0.66; high: ≥ 0.66), concentrated across arid and semi-arid inland regions. Distance to roads was the strongest predictor (mean importance 0.432), reflecting both dispersal along transport corridors and residual sampling bias. Soil phosphorus and pH ranked next, identifying these edaphic factors as potential constraints to establishment. Under Shared Socioeconomic Pathways climate scenarios SSP2-4.5 and SSP5-8.5, the area of moderate-to-high relative range probability increased to 53–56% of mainland Australia (3,952,768–4,236,669 km²). Climate change is projected to redistribute the potential range of buffel grass rather than just range expansion or contraction, with areas of high relative range probability becoming less extensive while the potential range becomes more geographically widespread. These projections provide a national basis for prioritising surveillance, early intervention, and coordinated management, particularly in currently unoccupied regions projected to have increasing relative range probability.</jats:p>