RESPONSES OF LIZARDS TO 3 EXPERIMENTAL FIRES IN THE SAVANNA FORESTS OF KAKADU-NATIONAL-PARK

A species-rich lizard community responded variably to a range of exper imental fire regimes in a tropical savanna. Heteronotia binoei was the only lizard species that showed a short-term response to fire, decrea sing in abundance directly after the early- and late-bums. H. binoei a nd Diporiphora bilineata were significantly more abundant in early-bur n treatments. Carlia amax was more abundant in unburnt and early-burn treatments. C. munda was more abundant in unburnt and early-burn sites . Differences in the relative abundance of species between treatments is attributed to site differences in vegetation structure, and fire-in duced changes to the structure of habitat. Early-burn sites were signi ficantly richer in lizard species (P<0.05); however, overall lizard ab undance, Shannon-Wiener diversity and Detrended Correspondence Analysi s (DCA) 1 and DCA 2 scores were not significantly different, suggestin g that habitat partitioning has a stronger influence than the direct e ffects of fire. Many lizards were associated with a direct gradient of moisture availability, including a seepage assemblage, with Carlia gr acilis and Sphenomorphus darwiniensis correlated with increased moistu re, a well-developed canopy and abundant leaf litter. An assemblage as sociated with the drier end of the gradient included Carlia triacantha , Ctenotus kurnbudj, Diporiphora magna and D. bilineata. The lizard co mposition of most quadrats was intermediate along the moisture gradien t and was associated with typical eucalypt savanna communities. Lizard species that largely are restricted to the moist seepage zones may be particularly sensitive to late dry-season fires which alter this habi tat type.