Fire studies in Mallee (<i>Eucaluptus</i> spp.) communities of western New South Wales: Spatial and temporal fluxes in soil chemistry and soil biology following prescribed fire

TitleFire studies in Mallee (Eucaluptus spp.) communities of western New South Wales: Spatial and temporal fluxes in soil chemistry and soil biology following prescribed fire
Publication TypeJournal Article
Year of Publication1996
AuthorsNoble J.C., Tongway D.J., Roper M.M., Whitford WG
JournalPacific Conservation Biology
Volume2
Pagination398-413
Date Published1996
ARIS Log Number098837
Keywordscommunities, Eucaluptus spp, Fire studies, New South Wales, prescribed fire, soil biology, soil chemistry, spatial, temporal fluxes
Abstract

The effects of prescribed fires on nutrient pools, soil-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 (immediately before and after the fire, after opening autumn rain, mid-season in the winter, and at the end of the spring) in five microsites (inner, middle and outer mallee litter zones, bare soil, and Triodia hummock). These samples were later analysed for pH, electrical conductivity, organic carbon and available nitrogen. The effect of fire on soil micro-organisms in these microsites was also examined by measuring nitrogenase activity and enumerating soil Acari. Carbon and nitrogen levels were consistently higher in the inner mallee microsites whereas bare soil sites provided the lowest values. Significant microsite times soil depth interactions were recorded in two shrubland sites while highly significant (P lt 0.001) depth times sampling time inteactions 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. Highest values were again recorded from the inner mallee microsites and the lowest from bare soil sites. 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 familes (15 genera) being enumerated in control sites compared with three families (three genera) only of Cryptostigmata. Nonetheless the most abundant mites were cryptostigmatids (Aphelacarus spp.) found in unburnt hummocks beneath Triodia plants. The ecological and management implications of these spatial and temporal fluxes in soil chemistry and soil biology are discussed in relation to their effects on landscape processes, particularly water and nutrient redistribution.

URLfiles/bibliography/96-PacConsvtnBiology-Whitford.pdf
DOI10.1071/PC960398