Document ID: chunk:federal_register_of_legislation:F2024L00346:reg:3:p4
Version: federal_register_of_legislation:F2024L00346
Segment Type: reg
Provision Reference: reg 3 (pt 4/10)
Character Range: 34810–37945

its pollination vector.

Photo © Elspeth Swan (left) and Debbie Reynolds (right)

Recruitment in situ
The majority of Spiny Rice-flower populations consist of mainly mature individuals (McCaw 2014, 2020), which may indicate an obstacle to or failure of recruitment (Mueck 2000; Reynolds 2013). Spiny Rice-flower has been observed to have episodic germination and infrequent successful recruitment, i.e., seedlings are numerous at times but survival rate through summer are extremely low (Reynolds 2013; DELWP 2021). Across multiple sites on the Victoria Volcanic Plains, for example, the recruitment level measured by number of seedlings surviving the first summer was only 14% (Reynolds 2013). Seed production and seedling establishment appears to be inhibited by both drought conditions and higher than average rainfall (Foreman 2011, 2012). Drought limits the reproductive capacity of mature plants, while during wet years, pollinator activity may be limited leading to lower seed production. In addition, high rainfall that leads to floods can adversely affect seedling survival. Understanding the key environmental drivers for successful Spiny Rice-flower recruitment is therefore crucial to inform its management and recovery (Reynolds 2013).
Although the Spiny Rice-flower has a deep (up to 1.5 m) taproot that can form underground stems and facilitate resprouting after biomass removal events (e.g., fire), it does not have the capacity to reproduce vegetatively (Mueck 2000; James & Jordan 2014).

Figure 5 Left-Spiny Rice-flower root formation. Right- close up of tap root and underground stem formation of a mature Spiny Rice-flower.Photo © Debbie Reynolds

Fire ecology
Exposure to differences in fire frequency may contribute to the morphological differentiation between populations. The 'northern form' populations (i.e. those north of the Great Dividing Range) consist of more vigorous adult plants (that have not been exposed to burning) than 'southern form' that are regularly affected by burning. Northern populations have been observed to have almost certainly declined more dramatically than the southern, basalt plain populations (DSE 2008; Appendix 1), indicating that appropriate fire regimes is paramount to support recruitment and population persistence.
Spiny Rice-flower germination and seedling establishment are substantially impeded when inter-tussock space diminishes (Morgan 1998; Lunt & Morgan 2002). Fire opens up the vegetation and creates bare ground and gaps, providing an opportunity for the Spiny Rice-flower to recruit from the soil seed bank. Fire also creates inter-tussock spaces important for seedlings to establish and mediates the coexistence of other native grassland species by interrupting the exclusion of competitors (DAWE 2022). Low competition induced by fire events combined with good seasonal rainfall may promote successful recruitment of Spiny Rice-flower (Mueck 2000; Carter & Walsh 2006; DELWP 2021). Despite the availability of bare ground, recruitment of the Spiny Rice-flower post-fire can be low, particularly following hot summers and low rainfall (Mueck 2000).
While