Indices of fire characteristics in sandstone heath near Sydney, Australia

Abstract

The relative sensitivity and performance of post-hocindices of fire characteristics were examined in a heathland area burnt in1994. Sites burnt at differing times before 1994 were selected andqualitatively allocated to classes of high and low crown damage. Subsequentmeasures were made of height of consumption of crowns, length of the deadportion of Xanthorrhoea resinifera leaves, and minimumtip diameters of burnt branches of the shrubs,Banksia oblongifolia andBanksia ericifolia. Results indicated that significantdifferences in mean, minimum tip diameter corresponded to contrasting classesof crown damage (larger mean tip diameters in high crown damage sites). Meanminimum branch tip diameter in B. oblongifolia was notsignificantly correlated with fuel age but significant correlations were foundwith estimates of rate of spread and Byram fire intensity at the study sites.The minimum branch tip diameter method has potential for further developmentand use as an indicator of fire intensity in heathland vegetation.