Bushfire Hazard Assessment & Management Plan v1 - 9A Jirrima Cres, Cooroibah

Bushfire Hazard Assessment & Management Plan v1                                                  NCES REF: J000706
Lot 101 on SP168341 – 9a Jirrima Cres, Cooroibah




2.3.1    Vegetation Hazard Class 22.1 – Melaleuca open forests on seasonally inundated
         lowland coastal swamps
Vegetation Hazard Class 22.1 (VHC 22.1) exists throughout much of the site and is present as open
forest in the west and scattered regrowth vegetation within adjacent unmanaged areas.
Within the west VHC 22.1 exhibits an average canopy height of approximately 15m with a
percentage crown cover (PCC) of 30-40%. The canopy is dominated by Allocasuarina littoralis
(black she oak) and Melaleuca quinquenervia (broad leaved paperbark) with Eucalyptus racemosa
(scribbly gum) also occurring in lower densities.
The mid-storey contains wallum heathland and open forest species including Banksia integrifolia
(coastal banksia), Banksia robur (swamp banksia), Acacia ulicifolia (prickly moses), Acacia
cincinnata (coil-pod wattle), Hakea actites (wallum hakea) and Persoonia virgata (wallum geebung).
The understory is predominantly comprised of native grasses such as Imperata cylindrica (blady
grass), Cymbopogon refractus (barb wire grass), Gahnia aspera (saw sedge) and Xanthorrhoea
johnsonii (grass tree).
VHC 22.1 occurs as scattered regrowth Melaleuca and Allocasuarina over an unmanaged grassy
understorey in the centre of the site. Due to past clearing the majority of midstorey species have
been removed with the understorey comprised of Cymbopogon refractus (barb wire grass) and
Imperata cylindrica (blady grass). Weeds such as Setaria sphacelata (South African pigeon grass)
occur as the dominant understorey species within wetter areas flanking the gully. No evidence of
recent management of this area was observed. If left unmanaged the scattered regrowth areas are
expected to redevelop into a dense Melaleuca open forest similar to that occurring in the west of the
site. Therefore VHC 22.1 has been assigned to both the scattered regrowth and open forest areas.
VHC 22.1 is attributed a potential surface fuel load of 23.4 t/ha and an overall fuel load of 28.4 t/ha
(QFES 2019) and is assigned a High Potential Bushfire Intensity class on level ground (Leonard et
al., 2017).
Plate 4-5 depicts typical conditions within VHC 22.1.




                      Plate 4 – Characteristic vegetation within VHC 22.2 (scattered regrowth)




© 2020                                                    8