Narrow-leaf Melichrus  |  

Threats The largest threat to the species is bushfire; especially given that climate change is increasing the frequency and severity of bushfires and droughts in Australia (CSIRO Bureau of Meteorology 2015).

Table 1 Threats impacting Narrow leaf Melichrus Threat Status and severity a Evidence Climate change and fire Fire related threats Timing current The CSIRO Bureau of Confidence known Meteorology (2015) predict that Consequence catastrophic climate change will continue to reduce rainfall and increase Trend increasing temperatures on the east coast of Extent across the entire Australia; leading to increased fire range frequency and intensity (DPI 2020).

Catastrophic bushfire events like the 2019 2020 fires are likely to reoccur with increasing regularity as a result of climate change.

Increased temperature Timing current The CSIRO Bureau of intensity frequency and change to Confidence inferred Meteorology (2015) predict the precipitation patterns Consequence moderate east coast of Australia will Trend increasing experience decreased rainfall; Extent across parts of the increased frequency and severity of range droughts and elevated average temperatures under climate change.

Surveys following the 2019 2020 bushfires indicate that 99 percent of the known range was impacted by fire; with no regrowth or seedling recruitment identified during post fire surveys (Auld et al. 2020 DPIE 2020).

If the Hairy Melichrus has similar fire ecology; post fire seedling recruitment for the species could be very low and sensitive to the season of fire; and some post fire resprouting of established pre fire plants may occur.

Narrow leaf Melichrus is threatened by several fire related threats; including high frequency fire; fire drought interactions; and fire promoted weed invasion.

A high frequency fire regime is likely to severely impact the Narrow leaf Melichrus due its restricted distribution in dry sclerophyll habitat (OEH 2019a).

Stochastic events such as bushfire are particularly threatening to the species; as a result of its limited distribution and population size (OEH 2019a).

This increases the likelihood of population extinction following a bushfire that destroys a Threatened Species Scientific Committee Melichrus Sp.

Fire intensity and severity was variable across the fire affected region; with many areas burning at extreme intensity and severity while others burnt at comparatively low intensities (DPI 2020).DAWE (2020b) estimated that the 2019 2020 bushfires overlapped with approximately 60.1 of the range of the Narrow leaf Melichrus.

Six months post fire; surveys of the known area of the species in Gibberagee State Forest found that no plants survived; indicating that a high temperature fire affected the population (Copeland 2020 J Brown 2020. pers comm 18 June; as cited in Kennedy et al. 2020).

Only two shoots (possibly root suckers or seedlings) have been observed since the fires (J Brown 2020. pers comm 18 June; as cited in Kennedy et al. 2020) despite significant rainfall; indicating that regeneration and recruitment post fire is extremely limited.

The fire response of the species is currently being monitored (Copeland 2020) but the recovery prospects for this Threatened Species Scientific Committee Melichrus Sp.

These changes are likely to cause widespread changes to forest ecosystems; as many plants are vulnerable to drought stress and hydraulic failure; particularly if fire has preceded drought (Burgman and Lamont 1992; Choat et al. 2018).

Lantana also can change fire patterns in forest ecosystems by altering fuel load; causing a build up of fuel that increases the risk of fires spreading to the canopy (Berry et al. 2011).

The effects of dieback may also be exacerbated post fire due to altered hydrology and increased surface runoff (Barrett 1996 Moore et al. 2015).

Narrow leaf Melichrus is threatened by several fire related threats; including high frequency fire; fire drought interactions; and fire promoted weed invasion.

These changes are likely to cause widespread changes to forest ecosystems; as many plants are vulnerable to drought stress and hydraulic failure; particularly if fire has preceded drought (Burgman and Lamont 1992; Choat et al. 2018).