CLIMATE, GRAZING AND DISTURBANCE, AND THE POPULATION-DYNAMICS OF LEUCOCHRYSUM ALBICANS AT ROSS, TASMANIA

A population of an endangered daisy, Leucochrysum albicans (syn. Helip terum albicans), was monitored monthly in grazed and ungrazed plots fo r several years in a paddock near Ross, Tasmania. The population decli ned dramatically during the extremely dry summer of 1987, and also exp erienced high mortality in the dry summer of 1988. Adult plants and ge rminates were more abundant in grazed than in ungrazed plots for most of the period after this decline. The development of axillary branches on adult plants was much more prominent outside than inside the exclo sures. Seedling establishment preferentially occurred on ground domina ted by herbs, with establishment being low and extremely brief on gras s-covered ground. The frequently disturbed margins of the exclosures w ere the most favourable sites for establishment of new individuals. Th e future of this unpalatable rare species seems to be dependent upon m anagement that maintains open and, preferably, disturbed ground.