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Like all savannas, the semi-arid tropical savannas of northern Australia have evolved with fire. However, the presence of fire in the landscape has changed significantly with the reduction of traditional Aboriginal burning and increased control of wildfires. The incidence of fire is now greatly reduced on most land used for grazing by livestock. To address concerns about how reduced fire might influence vegetation structure and productivity, a long term fire experiment at Victoria River Research Station, al so known as Kidman Springs, 400km south of Darwin in the Northern Territory began in 1993. Treatments (each with two replicates) include: season of burning (early in the dry season in June, or late in the dry season in October); fire interval (two, four and six–yearly); and four unburnt controls. The treatments are applied on a calcarosol Eucalypt woodland and on a vertosol grassland. The three decades have seen unanticipated climate driven shifts in pasture composition, and increases in woody cover in all but the most intense fire regimes and subsequent declines during a recent run of drier years. Fire prevented woody cover increases since 2009 on the grassland. On the woodland woody cover fluctuated more through time, but was at similar or lower levels in 2023 to 2009, even on unburnt controls due to drought related dieback. The herbaceous understorey is resilient to fire with perennial grasses relatively unaffected and greater diversity post fire due to increases in ephemerals. Understorey herbaceous dry m atter was only negatively correlated with woody cover on the grassland. Hence, concerns about increasing woody cover leading to reduced pasture productivity may be unfounded in th e woodland, but without fire native woody encroachment into the productive grasslands can change the structure from a grassland to an open woodland and may negatively impact carrying capacity for livestock. Since 2013 wet season spelling has been implemented post fire. This has improved the pasture composition on the grassland and suggests the minimum required fire interval for effective management of woody cover could be increased from four to six yearly, provided fuel loads are adequate for an effective fire. Other research at the site has investigated biocrust, mite, faunal and above and below ground carbon storage response to long term fire regimes. This is the only long term grazed fire experiment in Australia's tropical savannas. It continues to provide new insights and is open to the global research community.