SAFARI-92 CHARACTERIZATION OF BIOMASS AND FIRE BEHAVIOR IN THE SMALL EXPERIMENTAL BURNS IN THE KRUGER-NATIONAL-PARK

As one of the ground component projects in the South African Fire-Atmo sphere Research Initiative (SAFARI-92) the herbaceous fuel loads, comp rising mainly fine grass fuels, were characterized before and after th e application of controlled burns to small experimental plots, approxi mately 7 ha in size, situated in moist savanna in the Pretoriuskop sec tion of the Kruger National Park. The grass fuel loads were estimated before and after the controlled fires with a disk pasture meter (DPM) which comprises a circular aluminium disk fitted with a measuring rod and which relates the settling height of the disk to the quantity of g rass material holding it off the ground. One hundred readings were rec orded in each plot before and after the burns, and these data were use d to estimate the quantity of fine fuel consumed during the fires. Sur veys were conducted to describe the botanical composition and structur e of the grass sward and tree and shrub vegetation in the plots prior to burning. The fuel moisture, air temperature, relative humidity, and wind speed and direction were recorded for each fire. Fire behavior p arameters comprising rate of spread, fire intensity, and flame height were estimated for the head and back fires occurring during each burn. The results showed that the fine fuel loads on the plots varied great ly ranging from 323 to 4495 kg ha(-1). Generally, the behavior of the head fires was more variable than the back fires with fire intensities varying from 93 to 3644 kJ s(-1) m(-1) for the former and 20 to 160 k J s(-1) m(-1) for the latter.