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

                                                 Noosa Biodiversity Plan – Biodiversity Assessment Report




human infrastructure, as well as by steep land (Low, 2011). Saltmarshes are vulnerable to complete loss
of habitat, especially when bounded on the upper slope by cliff lines or coastal development (Steffen et
al., 2009, Low, 2011).

In addition, mangrove encroachment on saltmarshes may occur more rapidly than saltmarsh expansion
into higher land, which may be occupied by paperbark forests, freshwater sedgelands, or urban areas,
resulting in a contraction of the saltmarsh zone until some decades after future sea levels stabilised (Low,
2011). The extent of mangrove invasion of saltmarshes will be determined by localised rainfall changes
(Low, 2011).

Mangrove encroachment into saltmarshes is currently occurring at various locations in Queensland and
this process, in combination with barriers to landward movement, suggests that climate change will reduce
the extent of saltmarsh in many areas (Low, 2011). It is likely that mangroves will benefit from this process
(Low, 2011).

One of the wetland ecosystems that is most at-risk from climate change impacts is the freshwater
wetlands found immediately upslope of saline wetlands, which form much of the coastline of Queensland
e.g. paperbark Melaleuca spp. woodlands, and wetlands dominated by spike rush Eleocharis dulcis (Low,
2011).

Birds and flying foxes that feed on the nectar of paperbarks Melaleuca spp. growing in low-lying swampy
areas will also be impacted, where these vegetation communities are unable to migrate upslope (Low,
2011). In southern Queensland, the low-lying Melaleuca quinquinervia are a critical winter-spring nectar
source for flying foxes and honeyeaters, which are crucial pollinators for these and other dominant tree
species in the area (Low, 2011).

More frequent vegetation die-backs
Noosa Shire contains vegetation that will be more susceptible to die-back in the future. The Noosa region
is expected to experience longer dry spells (Low, 2011) and 20-40% more frequent droughts by 2030,
including more within-year droughts (Low, 2011). In combination with higher temperatures, this will
increase drought deaths, alter plant competitive relationships, and increase the risk of fire in some habitats
(Steffen et al., 2009). Areas that are particularly susceptible to drought-related deaths and die-backs
include dune crests, ridgetops, sunny northern slopes, and rainforests where shallow soils overlay rock.
Other rainforest areas are generally resilient to droughts, however, there are known examples of rainforest
trees dying during drought, all in the highlands of Southeast Queensland; in Yarraman, Lamington
National Park, and on Kroombit Tops (Low, 2011). Eucalypt forests in exposed areas and on shallow soils
are particularly susceptible to drought (Low, 2011).

Vegetation die-back, particularly in eucalypt and rainforest communities, may also occur due to cyclone
and hailstorm damage, with both of these ecosystem disturbances projected to increase in frequency and
intensity in the Noosa region in the future (Leslie and Karoly, 2007, SCC, 2010).

Reduction or loss of native folivores
Noosa Shire is home to both threatened and common folivores that are likely to decline due to a reduction
in leaf nutritional content as the amount of CO2 in the atmosphere increases. Plants supplied with extra
CO2 usually produce foliage with a reduced nitrogen content, and nitrogen is often the limiting resource
for herbivorous mammals (Low, 2011). Consequently, mammalian folivores will need to eat more leaves
to survive, which may not be possible under some circumstances, or it may lead to higher levels of
exposure and predation, and parasitism (Low, 2011). In addition, increases in CO2 also lead to greater
leaf thickness and the production of more secondary compounds such as phenols and tannins, which



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