Changes in tiller and tussock characteristics of Astrebla lappacea (curly Mitchell grass) after burning.

Abstract

Tiller and tussock characteristics of Astrebla lappacea (curly Mitchell grass) were studied at nine locations burnt by wildfires in north-west Queensland. Tussock number increased after burning although basal area was not affected. New tiller number (per quadrat) was not related to either tussock basal area or post-fire rainfall on burnt plots. Production of new tillers in unburnt plots was inversely related to the number of old tillers. New and old tiller weights were negatively related to tiller number per unit basal area. New tillers from burnt plots had higher 1eaf:stem ratios than new tillers and axillary shoots from old tillers in the unburnt plots. Dry matter production, two years after burning, was similar in burnt and unburnt plots despite the presence of more old tillers and fewer new tillers in the areas burnt by wildfires. Most tillers died within three years of being produced.