In some locations; particularly on estuarine soils located in sumplands; changed hydrology can also lead to the development of acid sulphate soils (Singh et al 2012); limiting suitability for many plants. 2.2.3 Climate The ecological community occurs throughout the latitudinal range of the Swan Coastal Plain; and as far north as Jurien Bay.

This seasonal climate predisposes the ecological communities in the region to summer fires but fire regimes are likely to have changed substantially since European occupation.

The climate is also changing; with a substantial decrease in rainfall in recent decades (Hope et al 2015 also see Section C.6 Climate change).

Predation by cats and foxes continues to limit population recovery for many small to medium size mammals; while other factors such as climate change and disease may also be limiting (Abbott 2008).

The primary known threats to the ecological community are listed here in categories; but these threats often interact; rather than act independently. 4.2 Primary threats to the ecological community For a detailed description of threats; see Appendix C Clearing and fragmentation of vegetation associated with o Agriculture and grazing o Logging and timber removal o Urban development and infrastructure o Mining and Quarrying Invasive flora and fauna o Weeds o Invasive vertebrate animals o Invasive invertebrate animals Tree dieback and pathogens Altered fire regimes Climate change Water extraction and other hydrological change Loss of fauna supporting key ecological processes 4.3 Key Threatening Processes The Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) provides for the formal identification and listing of key threatening processes (Part 13 Section 183).

The changing climate is an ongoing threat to integrity throughout the region.

Restore wildlife corridors and linkages (where appropriate) between remnants of the ecological community and other areas of native vegetation or reconstructed habitat; to reduce fragmentation and isolation and assist likely resilience to impacts of climate change.

Urban development also results in hydrological change and eutrophication through urban runoff; water diversion and groundwater extraction; as well as regional climate change; for example; due to urban heat islands.

This has been associated with the canker pathogen Neofusicoccum australe; which may be spreading its range in response to climate change (Dakin et al 2010).

Climate change is likely to compound changes to fire regimes (Hope et al 2015) as are changes to vegetation; such as the increase in annual; and highly flammable grass weeds.

C.6 Climate change Climate change is affecting southwest Western Australia at a rapid rate.

The climate change occurring throughout the region is having direct ecological effects and is also likely to have indirect threats and interact with other factors such as fire regimes.

In the long term; climate change is likely to change the character of the community by altering resource availability and the competitive relationships between species.

Greater fire frequency due to changed climatic conditions is likely to affect the ability of plants to recover and recruit; as well as impacting on faunal populations.

Horwitz et al (2008) describe some of the contributing elements; including climate variability; patterns of land use change; in particular to vegetation cover; patterns of water regulation; patterns of groundwater extraction and water infrastructure.

The extent to which the understorey is grassy or shrubby may depend in part on impacts of fire and grazing and weed invasion.

For example; the frequency and intensity of fire may influence the level of cover or floristic assemblage.

For example; the frequency and intensity of fire may influence the level of cover or floristic assemblage.

While a substantial proportion of the remnants of the ecological community with the best condition are in conservation reserves; these areas are not immune to threats such as weed invasion; fire and Tuart decline.

This has occurred through a wide range of events; including thinning and selective logging of large trees reducing habitat availability Tuart decline changed hydrology and extreme weather impacts of borers and other invertebrates as well as impacts of disease and changed fire regimes.

The more southerly areas retain greater areas of the ecological community; with some large patches retained in formally protected areas; but these areas have also been susceptible to a range of major landscape threats including widespread invasion by weeds; severe fire events and major damage through Tuart decline.

Specifically note that elevated weed infestation and subsequent increased fire risks will result if weed control is not undertaken. o Refer to State Planning Policy 3.7 (SPP 3.7) Planning in Bushfire Prone Areas.

SPP 3.7 to assist in planning that will reduce the risk of impacts of unplanned fire to the ecological community; as well as reducing the risk to life and property.

Unburnt areas may provide refuge for; as well as source populations for recovery. o Avoid physical damage to the habitat and individuals of any threatened species during and after fire operations. o Ensure that he season of burning does not have negative impacts on the integrity of the community and understorey; species diversity and natural life cycles of component species; for example do not burn during reproductive seasons of threatened or functionally important species o Protect tree hollows; for example by minimising high intensity fires; removing fuel from the base of trees; without damaging understorey plants; and extinguishing fires from the bases of the relevant trees after the fire front has passed.

It is likely that one of the changes has been the scale of burning undertaken at any one time as well as its frequency.

With the establishment of some conservation parks (e.g Yalgorup National Park) there was a policy of fire exclusion introduced which significantly changed the historical fire regimes (Wilson pers.comm); while more broadly; legislation such as the Bushfires Acts of 1902 and 1937 limited the season of burning (Abbot 2003).

The ability of patches to recover from disturbances such as disease or fire may be reduced where there is little adjacent habitat (although spread of fire threats may also be reduced).

At Paganoni; excluding grazing after a fire did not change the native species richness; but the native species cover; particularly by shrubs ; as well as some native grasses and geopyhytes was higher inside fenced areas (Brown et al 2016).

Increased human populations near natural areas may lead to their appreciation but there is increased pressure on these areas; with problems including profusion of bike and four wheel drive trails; weed invasion; cubby construction; increased fire frequency and intensity (including through arson); rubbish dumping; mowing or tidying up native areas and firewood collection; as well as impacts of busy roads adjacent to the natural areas (Del Marco et al 2004 Conservation Commission of Western Australia 2010).

Populations of some insects may have increased with canopy opening and changed fire characteristics (Ruthrof et al 2002).

It is likely that fire frequency has increased in some areas; while in others fire has been largely excluded; but may be subject to occasional intense fires.

Archibald (2005) suggests that in Yalgorup National Park; fire frequency may have reduced substantially and threatens the ecological community though evidence indicate for many ecosystems a substantial increase in fire frequencies in post European times (see Crosti et al 2007.

Likely effects of the changed fire regimes include changes to nutrient cycling; competition; increase in flammability; weed increase and altered plant regeneration.

Grassy weed invasion; for example; by perennial veldgrass (Ehrharta calcina) is a particular problem that is enhanced by fire; and may in turn also enhance fire risk (Fisher et al 2009); through increased flammability and ignition capability.

While no single fire regime will be suitable for all desired outcomes; Burrows (2008) recommends that the interval between fires be at least twice the period for maturity of the slowest maturing of the fire sensitive species; for example Hibbertia cuneiformis; Leucopogon racemulosus; Beyeria cinerea; Ricinocarpos glaucus; Alyogyne huegelii; Myoporum insulare; Chamelaucium uncinatum.

Threatened fauna species in the ecological community considered susceptible to fire include Baudin s and Carnaby s cockatoos; Western Ringtail Possum and Southern Brush tailed Phascogale.

The 2016 Waroona Yarloop fire had a devastating impact on the flora and fauna of the area ; including loss of foraging and breeding habitat for black cockatoos (Johnstone and Kirkby 2016).

The impacts of these burns are likely to result in loss of soil organics that are critical for understorey health loss of fire sensitive understorey species that require longer fire free intervals (e.g. multiple decades) to regenerate exacerbation of the weed cover both in extent; density and potentially diversity of weeds leading to higher flammability and greater risk to the ecological community including; greater risk to wildlife with aseasonal burning impacting on breeding cycles and periods of occupancy within the ecological community.

Correspondingly; time spent in drought is expected to increase; while fire weather is also expected to increase (Hope et al 2015 CSIRO and Bureau of Meteorology).

D.2.5 Conclusion Given the limited area and very restricted patch distribution of the ecological community and likelihood of ongoing area loss and fragmentation; threats such as weed invasion; inappropriate fire regimes or Tuart decline will plausibly lead to its loss within the near future (considered to be 5 generations of Eucalyptus gomphocephala; up to the threshold of years; for this ecological community) 2.

Some of the same areas where then affected by a severe fire event in 2016; followed by tree removal to address public safety concerns; increasing the losses and compromising recovery.

More recently there have been other causes of loss identified; such as hydrological change and diseases including Phytophthora cinnamomi (affecting species such as Jarrah); and P. multivora; (which may affect Tuart); as well as long term changes in fire regimes (Scott et al. 2009).

The loss of understorey layers is also likely to have altered underlying biophysical qualities and processes; for example; soil characteristics; fire behaviour and hydrology.

In response to changes such as vegetation clearing and fragmentation; as well as other disturbances such as disease; grazing; introduction of new predators and change to fire regimes across the region many of these species have reduced populations or ranges.

This has occurred through a wide range of events; including thinning and selective logging of large trees reducing habitat availability Tuart decline changed hydrology and extreme weather impacts of borers and other invertebrates as well as impacts of disease and changed fire regimes.

Correspondingly; time spent in drought is expected to increase; while fire weather is also expected to increase (Hope et al 2015 CSIRO and Bureau of Meteorology).

Changes to hydrology and extreme weather events are also suspected to have caused losses of Tuart trees.