2016-12-12 General Committee - Attachment 1 to Item 6 - Biodiversity Assessment Report

                                                  Noosa Biodiversity Plan – Biodiversity Assessment Report




Appendix E Climate Change Impacts Literature
Review
Extensive coastal erosion and inundation
Noosa Shire has extensive stretches of low-lying coastal and dune ecosystems, which are highly
susceptible to coastal erosion and inundations. Global sea levels are anticipated to rise between 36 cm
and 1 m by 2100, with an upper limit of ~2 m based on new ice-sheet understanding (IPCC, 2007, Allison
et al., 2009). However, these global estimates may increase by up to a factor of four in northern Australia,
where sea levels are currently rising at about four times the global average (Steffen et al., 2009, Low,
2011). Looking further into the future, sea level will continue to rise for centuries after global temperatures
have stabilised, and several meters of sea level rise are to be expected (Allison et al., 2009).

Greater storm intensity and/or frequency, increased cyclone activity (Easterling et al., 2000; Low, 2011)
including the cyclone decay zone shifting south by 200-300 km by 2050 (Leslie and Karoly, 2007), and
increased coastal winds, will all lead to greater coastal erosion and more frequent episodic inundation of
coastal areas.

Sea level rise will significantly impact coastal fauna, particularly wetland and shorebirds, which feed and
breed in low-lying wetlands (Low, 2011). Rising sea levels could result in a contraction of the saltmarsh
zone until some decades after future sea levels stabilised. This would have significant consequences for
waders and other fauna that feed and breed in saltmarsh and other low-lying areas (Low, 2011).

More frequent mass die-off of vulnerable flora and fauna
Noosa Shire has several species of flora and fauna that are susceptible to mass die-off from hot
conditions. Annual mean temperatures in south-east Queensland are expected to increase by up to 1oC
by 2020, 2oC by 2050, 4oC by 2075, and up to 6.5oC by 2100 (SCC, 2010). In conjunction with a general
warming across the region, there are expected to be an extra 30 days per year of temperatures over 35oC
in south-east Queensland by 2100 (SCC, 2010).

Higher mean temperatures and an increased frequency of extremely hot days (Noosa Biosphere, 2012)
increase the likelihood of temperatures exceeding the upper critical thermal limit of vulnerable flora and
fauna species. These impacts are species-specific, and depend on the species ability to physiologically
tolerate, or (for fauna) behaviourally adapt to extended periods of hot conditions.

Higher temperatures can kill seedlings and herbs, leading to unpredictable shifts in vegetation
composition in some habitats (Low, 2011). This is particularly critical in areas that are currently acting as
cool climate refugia (e.g. rainforests, southerly slopes, shaded creeklines) for susceptible flora and fauna
species. The species most vulnerable to rising temperatures come from large and thermally stable
rainforest refugia where they have a limited physiological or behavioural capacity to cool themselves
(Low, 2011). For example, the cascade treefrog Litoria pearsoniana of the Noosa region has a low Critical
Thermal Maximum (CTM) of 32-34.4oC (Low, 2011), and is unlikely to survive outside rainforests. In
contrast, the wallum rocketfrog Litoria freycineti from the same genus has a high CTM of 37.5-39.1oC
(Low, 2011) and will have greater capacity to adapt behaviourally within Wallum habitats, to avoid high
temperatures.

Flying foxes are one group of fauna that are particularly vulnerable to mass die-offs caused by excessively
hot conditions. Mass die-offs within flying-fox roosting colonies are known to occur when temperatures
reach maximums of 41.7 to 43.4 °C (Low, 2011). Within the last 15 years, mass die-offs in flying fox


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