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ARS Home » Plains Area » Las Cruces, New Mexico » Range Management Research » Research » Publications at this Location » Publication #98837
Title: FIRE STUDIES IN MALLEE (EUCALUPTUS SPP.) COMMUNITIES OF WESTERN NEW SOUTH WALES: SPATIAL AND TEMPORAL FLUXES IN SOIL CHEMISTRY AND SOIL BIOLOGY FOLLOWING PRESCRIBED FIRE

Author
item NOBLE, J - CSIRO AUSTRALIA
item TONGWAY, D - CSIRO AUSTRALIA
item ROPER, M - CSIRO AUSTRALIA
item Whitford, Walter

Submitted to: Pacific Conservation Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: We studied the effects of fires on soil nutrients, micro-organisms and vegetation at two soil depths (0-2 cm and 2-4 cm) and five areas (inner, middle and outer mallee litter zones, bare soil and hummocks of Triodia) in three semi-arid shrublands. Carbon and nitrogen was lowest in bare soil areas and highest in the inner mallee areas. The inner mallee also had the highest levels of soluble minerals. Prostigmata micro-organisms were the most abundant in unburnt areas and were totally replaced by Cryptostigmata mites in burnt areas.

Technical Abstract: The effects of prescribed fires on nutrient pools, soil micro-organisms and vegetation patch dynamics were studied in three semi-arid mallee shrublands in western New South Wales. Repeated sampling of surface soil strata (0-2 and 2-4 cm) was undertaken at strategic times in five microsites. Samples were analyzed for pH, electrical conductivity, organic carbon and available enitrogen. The effect of fire on soil micro-organisms in these microsites was examined by measuring nitrogenase activity and enumerating soil Acari. Carbon and nitrogen levels were consistently higher in the inner microsites whereas bare soil sites provided the lowest values. Significant microsite x soil depth interactions were recorded in two shrubland sites while highly significant (P < 0.001) depth x sampling time interactions were recorded in three sites. The most sensitive soil parameter with respect to microsite was electrical conductivity, particularly in the surface 0-2 cm stratum. Nitrogenase activity was highest in soil samples associated with mallee litter and, where litter was removed by fire, activity decreased markedly except in the bare soil samples where activity was higher in the burnt samples. Soil microarthropod populations also declined notably following fire. Mites from the Prostigmata greatly outnumbered those from other suborders, a total of 12 families (15 genera) being enumerated in control sites compared with three families (three genera) only of Cryptostigmata. The most abundant mites were cryptostigmatids (Aphelacarus spp.) found in unburnt hummocks beneath Triodia plants.