Late Holocene fire history and palaeoecological conditions at Dunphy Lake, Warrumbungle National Park, New South Wales, Australia

There is a significant geographical and temporal gap in the Holocene environmental record of fire, hydrology and palaeoecological conditions in the region of the Warrumbungle Mountains in eastern Australia. Dunphy Lake (-31.3076°S, 149.0149°E) is a small, ephemeral freshwater wetland within Warrumbungle National Park, and the only example of its kind in this temperate -semiarid region. Late Holocene fire history and palaeoecological conditions at Dunphy Lake were determined using a multiproxy approach that incorporates geochronological, limnological and geochemical techniques. The sediment profile at Dunphy Lake is dominated by mud (< 63 µm) and the macrocharcoal record indicates that the largest local fire events have occurred since 1,793±28 years BP. Some distinct peaks in macrocharcoal are coincident with peaks in sand (63-2000 µm) content, suggesting that some fires occurred at similar times to episodes of significant runoff and sediment flux from the catchment. Recent palaeoecological conditions were conducive to a relatively complex aquatic food web, as shown by the presence of micro- and macro-invertebrate and diatom remains in the upper sediment facies. A geochemical record derived from ITRAX core scanning shows facies with elevated pedogenic (e.g. Mn, Ca) and detrital (e.g. Si, Ti) elements, but does not show a significant increase in anthropogenic elements at the surface. Altogether, this multiproxy approach yields a record of fire and aquatic conditions that can be used to place historical and contemporary fires and vegetation changes in this region into context.