Mistletoe flora (Loranthaceae and Santalaceae) of the Kimberley, a tropical region in Western Australia, with particular reference to fire

Abstract

The mistletoe flora of the tropical Kimberley region of Western Australia was studied over a 30-year period, with a particular emphasis on distributions, use of hosts and effects of fire. The results were compared with those of a similar study undertaken in the Pilbara, a more arid tropical region in the same State. The flora consisted of one genus with three species in the Santalaceae and five genera with 22 species (one with two varieties) in the Loranthaceae. Amyema was the largest genus in both regions. Four species are regarded as Kimberley endemics but two of them may also occur in the Northern Territory. Most species occurred in three or more of five Kimberley bioregions. However, six species were recorded only from the North Kimberley where they were all rare. Host records included 165 species from 33 families. Fabaceae (particularly Acacia) and Myrtaceae (particularly Eucalyptus and Corymbia) were the most important. The perfect dichotomy between species using fabaceous and myrtaceous hosts in the Pilbara was strong but imperfect in the Kimberley. Fire responses of two species were not observed. Two (perhaps three) taxa were able to resprout, whereas the remaining taxa were killed if scorched. Most species occurred, at least occasionally, in relatively fire-safe refugia. Nevertheless, fire is eroding distributions of many species and may be threatening some, particularly the rare North Kimberley species.