Seedling emergence of hummock grasses in relation to the effects of fire.

Abstract

The ecology of hummock-grass vegetation involves recurring fires. The hypothesis was tested that soil seed banks of hummock grass species are stimulated to germinate by the heat of fire or by ash addition. Hummocks of Plectrachne schinzii Henr., Triodia basedowii E. Pritz., and Triodia pungens R. Br. were burned, removed, or removed with the ash returned, and subsequent regeneration was recorded, in Ulum National Park. Regeneration of hummock grass was by seedlings only. Seedling emergence averaged 5/m2, with no differences between treatments or hummock grass species. This indicates the heat of fires and ash addition may not be important in stimulating seed germination of these hummock grass populations. Gemination was distributed over more than one rainfall event following the treatments.