Control of Hakea Preissii (Meissner) and Associated Species by Fire in Degraded Semi-Arid Rangelands.

Hakea preissii has been identified as an undesirable increaser which has invaded formerly productive semi-arid pastoral lands of Western Australia. This paper reports a study designed primarily to assess the susceptibility of H. preissii to fire and to assess the effects of fire on the associated plant community. Plant survival was assessed by comparing the response to a low and high fue fuel load with untreated control plots. Fire intensities of 2900 and 9300 kwlm were achieved with fuel loads of 500 g/m2 and were sufficient to kill 98% of H. preissii by two years after the burn. A fire intensity of 240 kwlm was achieved with 150 .g/m2 fuel load and was sufficient to kill 53% of H. preissii plants. Other perennial species, more highly regarded as sheep feed, including Scaevola spinescens, Rhagodia eremaea, Enchylaena tomentosa and Maireana tomentosa, were killed by fire while Eremophila "crenulata" and Senna species, which are regarded as undesirable increasers in this environment, were generally unaffected by even the most intense fie.