Seasonal changes in the nutritive value of grass species in Spinifex pastures of Western Australia.

Abstract

This study was undertaken to assess whether the nutritional quality of spinifex pasture lands is improved by buming to promote the growth of grasses other than spinifex. We selected two comparable sites in the Exmouth Gulf region of Western Australia; one had been bumt in late 1979 and the other had not been burnt for many years. On these sites we sampled the five grass species present, as well as Triodia pungens (soft spinifex) and Plectrachne >chinzii (Oat eared spinifex) on 10 occasions from March 1980 to April 1982. Plant parts were analysed for nitrogen, phosphorus and sulphur content, and in vitro digestibility. None of the common grass species tested was more nutritious or more palatable than soft spinifex. It seems that little is gained from manipulating spinifex pastures through burning if the aim is to encourage alternative grass species. There is a need however for further studies into the importance of woody herbs and forbs in the nutrition of grazing animals on spinifex country and the effect of fire on these species.

Response of a perennial grassland to nitrogen and phosphorus additions in sub-tropical, semi-arid Australia

“…Few trials included P-only additions (Table 2) but the available data suggest that P and N were co-limiting at plant ratios between 8 and 18 (Norman, 1962;Tupper, 1978). At four locations throughout semi-arid Australia (Christie, 1979;Silcock et al, 1985;Holm & Allen, 1988;Rice et al, 1994), ratios greater than 18 suggest some potential for P limitation of perennial grasses. Unfortunately, N and P concentrations (and full climatic and environmental variables) have been reported for few fertilizer trials and so more definitive identification of 'critical' N : P ratios for semi-arid grasslands remains elusive.…”

Resource pulses and mammalian dynamics: conceptual models for hummock grasslands and other Australian desert habitats

“…Post‐fire environments provide a community of grasses and herbs more palatable to mammalian herbivores than stands of long‐unburnt spinifex (Suijdendorp, 1981; Holm & Allen, 1988; Letnic, 2004). Thus fire‐mosaics are thought to offer animals a variety of habitats, including long‐unburnt areas with dense spinifex that are suitable for shelter, near to food‐rich regenerating areas that are suitable for foraging (Bolton & Latz, 1978; Lundie‐Jenkins, 1993).…”

Regeneration after fire in Triodia R. Br.

“…Suijdendorp considered the effects of different management practices on the success of seedling establishment following experimental burns. He also discussed the nutritional value of T. pungens seedlings and resprouts following fire, as did Holm and Allen (1988). Burbidge and Suijdendorp both commented that burned T. pungens pastures along the coastal strip were more likely to regenerate from the burned butts of adult plants, whereas the inland populations usually regenerated from seed only.…”