Published works

Samples of leaves, twigs and bark representing typical surface fuels from forests and woodlands were systematically heated and combusted under controlled conditions. Very little biomass, carbon (C) and nitrogen (N) was lost when heated at low temperatures to 200 ° and greatest losses occurred between 400 and 600

°C, regardless of the type of fuel burnt. Losses of C and N varied considerably with temperature. Carbon was lost when fuels were heated at temperatures of 300 °C or more. Nitrogen was relatively more abundant when heated at 400 °C, albeit at very low levels (less than 5%). When heating time was varied there were noticeable differences in patterns of weight loss and changes in proportions of C and N. This indicates that both fire intensity and residence time is likely to be important in understanding losses of C and nutrients during fire, particularly during low intensity prescribed burning.

The use of colour of residues after heating surface fuel has the potential to determine fire severity. Existing technology such as near infra-red scanners can measure ash colour, not only indicating fire severity but also, by association, C and N losses from fire. Combustion studies done in a well-controlled laboratory environment could be used to interpret fireground conditions in relation to fire intensity and residence time, according to the nature and amount of charred material, charcoal and ash that remains after fire.