Whicher 2 Bio-landscape

Posted on Dec 23, 2014


Whicher 2 bio-landscapeTerrestialBiodiversity

Priority Bio-landscapes were identified across the region in the 2009 Biodiversity Sub-strategy. A 5 km by 5 km grid was placed across the region and those landscapes that had the highest concentrations of biodiversity value within the region were identified. Those landscapes that were identified as having a combination of high rarity for flora/fauna/communities and vegetation associations were classified as Highest Priority bio-landscapes. Those that were identified as having high rarity for flora/fauna/communities but the vegetation associations within them were not rare were classified as Second Priority Bio-landscapes. The full report can be read here: 2009 Biodiversity Sub-Strategy

 

The Whicher 2 bio-landscape which is south west of Busselton, falls within the Shires of Busselton and Augusta-Margaret River and is within the Geographe Bay catchment.

A large part of the bio-landscape lies within the north-western part of the Blackwood State Forest with the remaining area being fragmented vegetation across private farming properties. The bio-landscape lies at the base of the Whicher Scarp and is the headwaters of Dawson Gully, Ironstone Gully, Buayanyup River and Vasse River.

There are several threatened ecological communities found within the bio-landscape, across numerous locations, including:

  • SCP10b – shrublands on southern Swan Coastal Plain ironstones (Commonwealth listed as Endangered)
  • Whicher Scarp C1 – Central Whicher Scarp Jarrah woodland (Priority 1)
  • Whicher Scarp G2 – Shrublands of near permanent wetlands in creeklines of the Whicher Scarp (Whicher Scarp community G2) (Priority 1)
  • Swan Coastal Plain Paluslope wetlands (Priority 1) and
  • Whicher Scarp C2 – Whicher Scarp Jarrah woodland of deep coloured sands (Priority 1).

More information on the Commonwealth listed Ironstone community can be found on the Glimpses into disappearing landscapes website here.

There are 23 DRF and 30 priority flora populations identified within the bio-landscape including species such as Banksia nivea subsp. uliginosa, Banksia squarrosa subsp. argillacea, Grevillea brachystylis subsp. grandis, Calothamnus quadrifidus subsp. teretifolius, Calothamnus lateralis var. crassus, Loxocarya magna, Andersonia ferricola and Lambertia rariflora subsp. rariflora.

Much more can be found out about the values of the vegetation of the Whicher Scarp, including the area in which this bio-landscape is located within the report, A Floristic Survey of the Whicher Scarp A report for the Department of Environment and Conservation as part of the Swan Bioplan Project April 2008 (Keighery BJ et al., 2008).

Although no threatened fauna records exist for this bio-landscape, it is more indicative of the lack of extensive surveying of the Whicher Scarp, rather than the diversity of fauna present. The EPA Bulletin No, 6; Natural Values of the Whicher Scarp (2009) notes that the Whicher Scarp supports a high number of threatened vertebrate species including the Baudin’s cockatoo, Carnaby’s cockatoo and the forest red-tailed black cockatoo, chuditch, western ringtail possum and phascogale as well as a high number of priority species including quenda, carpet python and western false pipistrelle.

Whicher 2 bio-landscape and Climate Change

Projected level of risk due to:

Decreasing rainfall

Best case   VeryHighCircle

Worst caseVeryHighCircle

 

Increasing temperature

Best case   ModerateCircle

Worst caseHighCircle

 

  • where Best Case = MIROC5 and Worst case = CanESM2 at 2090 and RCP8.5; see more here
  • Decreasing rainfall = annual rainfall change as % of initial
  • Where Very High = greater than 25% reduction; High = 20-25% reduction; Moderate = 15-20% (Note: no where in the region is there projected to be less than 15% reduction in rainfall).
  • Increasing temperature = change in maximum summer temperature
  • Where Very High = greater than 4 degree increase (maximum projected being 4.7 degrees within the Region); High = 3-4 degree increase; Moderate = 2.5 – 3 degree increase; Low = 2 – 2.5 degree increase (Note: no where in the region is there projected to be less than a 2 degree increase which although lower than the very high 4 degree increase, will still have significant impacts on the environment).

This analysis is a simplistic way of looking at the potential risk of an asset to projected changes in rainfall and temperature. Assets may respond to climatic changes differently and species may be able to adapt in ways we don’t yet fully understand.

SWCC Strategic Priority

The Whicher 2 bio-landscape is identified as a second order priority asset within SWCC’s NRM Strategy under the Terrestrial Biodiversity theme.

Projects

 

 

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