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

                                                 Noosa Biodiversity Plan – Biodiversity Assessment Report




         CO2 in the atmosphere increases. Plants supplied with extra CO2 usually produce foliage with a
         reduced nitrogen content, thicker leaves, and more phenols and tannins. Koalas are particularly
         susceptible to the impacts of lower nutrient and higher toxin content of foliage.
      6. Increase frequency in flooding caused by more storm activity and heavier rainfall events. The
         extensive riparian and wetland ecosystems of the Noosa Shire are expected to experience
         more frequent damage in the future, due to heavier rainfall events and more extensive and
         destructive flooding. Vegetation damage, particularly in eucalypt and rainforest communities,
         may also occur due to hailstorm damage, with both of these ecosystem disturbances projected
         to increase in frequency and intensity in the Noosa region in the future.
      7. More frequent weed incursions caused by more frequent and severe flooding, and greater
         natural ecosystem disturbance. Remnant and regrowth ecosystems within the Noosa Shire,
         particularly those in urban, agricultural and riparian areas, will become more susceptible to
         weed invasion in the future, due to increased storm damage. The increased damage to
         rainforests in particular, provide ideal opportunities for invading weeds to alter ecosystem
         dynamics and functioning.

The scientific basis of these impacts are detailed in Appendix D

4.2       Inv a siv e sp ec i es
Weeds and pest animals have been identified as one of the most significant biodiversity threats across
the shire (Noosa Council, 2015b). Weeds and pest animals outcompete and prey on native species,
smother and degrade natural ecosystems, alter fire regimes and can reduce or eliminate ecosystem
functions. Weed incursion is often a secondary impact following disturbances such as fire, grazing,
nutrient pollution and alterations to natural drainage patterns (Burrows, 2003). It should be noted that
some invasive species have become naturalised and in some areas have become an integral component
of some ecosystems, providing important function such as soil stabilisation and shelter habitat for fauna
species. Subsequent removal of such species in these areas should be carefully managed to ensure a
low risk of further impact.

Within the Noosa Shire the primary weed and pest threats can be categorised into five groups:

      •    Waterway pests – weeds species can dramatically alter environmental and physiochemical
           conditions and interfere with ecological processes of waterways and waterbodies, and aquatic
           pest animals can outcompete native species and predate on native aquatic reptiles, frogs, fish,
           crustaceans and insects.
      •    Coastal ecosystem pests – residential and tourist development pressures resulting in garden
           escapees of exotic species becoming prevalent in coastal environments and an increase in pest
           animals preying on marine wildlife such as nesting marine turtles.
      •    Rural area pests – exotic weed and pest species can cause loss of production, degradation of
           pasture, illness and injury to livestock and spread disease.
      •    Urban area pests – potential point source for weed incursions into neighbouring bushland
           reserves as well as provide an environment suitable for harbouring certain introduced species.
      •    Pests within the hinterland– exotic vines are prevalent in areas can smother native vegetation
           and impacting on fauna habitat.

A complete list of weed and pests species currently threatening Noosa’s biodiversity values is provided
in Table 5.




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