Document ID: chunk:federal_register_of_legislation:F2024L01095:body:0:p34
Version: federal_register_of_legislation:F2024L01095
Segment Type: other
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Character Range: 89119–92062

but perennial grasses may not recover in the short-term (≤ 12 years) (Wright et al. 2021). Native vegetation cover has also been observed to decrease with increasing presence of buffel grass (McDonald & McPherson 2011).

Buffel grass may reduce the seed viability and germination rates of some key perennial shrub species in arid and semi-arid communities (Edwards et al. 2019). This may reduce the accumulation of viable seeds in the seedbank, which is likely to reduce the efficiency of the plant community's response to sporadic rainfall events. Reductions in germination are also likely to lead to long-term declines in perennial shrub populations, leading to a substantially altered habitat composition and structure. Increased fire frequency and intensity linked to buffel grass invasion are likely to exacerbate these changes (Miller et al. 2010). Delaying the eradication of buffel grass increases the likelihood that the native seedbank will deteriorate, which may compromise restoration efforts (Wright et al. 2021).

The interaction between buffel grass and fire is of substantial concern for the preservation of Malleefowl habitat. Numerous studies have identified a positive feedback loop between buffel grass and fire, wherein buffel grass increases post-fire and promotes more frequent fire (Butler & Fairfax 2003; Miller et al. 2010; McDonald & McPherson 2013).

Buffel grass increases the intensity of fire on higher nutrient soils (Miller et al. 2010; McDonald & McPherson 2011, 2013), leading to less patchy fire, a greater proportion of burnt ground, a higher rate of canopy dieback, death of mature trees, and the acceleration of negative competitive effects and habitat degradation (Butler & Fairfax 2003; Miller et al. 2010; Schlesinger et al. 2013). It also increases the frequency of fire by carrying fire through vegetation communities that are otherwise not fire-prone (Marshall et al. 2012; McDonald & McPherson 2013). The inter-annual variation in buffel grass biomass is much lower than that of native plant species, and so it presents a more consistent fire risk (McDonald & McPherson 2013). Furthermore, even after treatment with herbicide, buffel grass stands may require several years of decomposition before they no longer support fire spread (McDonald & McPherson 2013).

Climate change is likely to increase the threat posed by buffel grass and enable it to expand its potential range (Read et al. 2020). With climate change, buffel grass may pose an increasing threat in southern Australia, while conditions in northern Australia are projected to become less suitable (Martin et al. 2015). The risk of buffel grass invasion within Australia's national reserve system is likely to increase with climate change (Martin et al. 2015).

Buffel grass invasion is also exacerbated by other threatening processes in arid and semi-arid environments, including cattle grazing (Fensham et al. 2013) and land clearing