The proposed Gai-mariagal Aboriginal-owned
National Park will protect threatened species and eight ecological communities
in the area some of which are not currently protected within the NSW Park
system. The area contains high species richness with at least at least
163 fauna and 517 flora species recorded locally.
The land provides connectivity for wildlife from Garigal National Park
West and Narrabeen Lagoon through to Wheeler Creek Valley via Oxford Falls
Valley. Connectivity like this will become increasingly important as the
rate of climate change increases. Connectivity of suitable habitat is
an important ecological function for urbanised flora and fauna. Large
areas of habitat provide this direct connect and reduce the need for species
to cross dangerous barriers i.e. major roads and urban areas in search
of resources such as food, water, shelter and prospective mates.
The proposed park will provide protection for the catchments of creeks
that flow into Narrabeen Lagoon which is Sydneys largest lagoon
and is recognised as a regional resource.
Increases in the population
of Sydney and in disposable income lead to increased pressure from various
forms of recreation some of which are destructive in bushland.
The area needs to be well managed to protect biodiversity.
The area is also known to contain Matters of National Environmental Significance
(EPBC Act 1999) including; 7 places on the Register of the National Estate
(RNE): 4 Natural Areas (Belrose Grevillea caleyi Site, Deep and Middle
Creeks Area, Mona Vale Road Bushland Corridor and Ku-ring-gai Chase NP),
one Indigenous Area (Wheeler Creek Valley Area) and 2 Historic Areas (Narrabeen
Lagoon Catchment, Upper Middle Harbour Area).
There is a World Heritage Property in the vicinity (Ku-ring-gai Chase
National Park 1 km to the west 3km to the north) and a Commonwealth listed
Threatened Ecological Community in the vicinity (Western Sydney Dry Rainforest
and moist Woodland on Shale - Critically Endangered ecological Community).
This portion of the Hornsby Plateau contains upland sites - remnant plateau
tops of generally low relief; headwater valleys with dish shaped profiles;
major valley sides the dominant landform - featuring low cliff
lines and intervening linear to concave-convex hillslopes; and valley
bottoms, which feature either a bedrock dominated stream channel or a
valley fill of deposited sediments.
On the Hornsby Plateau, the ecological significance of podzol (i.e. iron
pan layer under leached white sand) soils is the distinct differences
in plant associations that occur in otherwise uniform settings, according
to the presence or absence of a podzol. Species such as Christmas Bush
(Ceratopetulum gummiferum) and Grass trees (Xanthorrhoea arborea) are
two examples of species that favour podzol soils, while Scribbly Gum (Eucalyptus
haemastoma) may grow in proximity to but rarely if ever on podzol soils
(Buchanan and Humphreys, 1980).
A further important characteristic of the sandstone is its linear joint
structures - breaks in the body of rock which may form along planes of
weakness either inherited from the original sedimentary materials or resulting
from the process of lithification. These joints may be orientated laterally,
vertically or at some intermediate angle. Joints which penetrate some
metres to tens of metres through the sandstone strata are particularly
important in the long term processes of mechanical weathering and drainage
development described in the following sections.
Some minor occurrences of basaltic igneous rock have been identified in
the Middle Creek catchment in the form of small dyke features. This rock,
in stark contrast to the Hawkesbury sedimentary unit, contains no quartz
mineral and weathers readily at the outcropping surface to yield clay
materials some of which had economic value during Aboriginal occupation
of the area and close to which ceremonial sites were established.
There are records of 39 Commonwealth-listed Threatened Species (6 Birds,
2 fish, 5 frogs, 8 Mammals, 1 reptile and 16 plants) and 13 migratory
species (all birds) and 14 listed Marine Species (All birds) in the vicinity.
(Commonwealth Department of Sustainability, August 2013)
There are records of at least 20 Threatened fauna state-listed species
and 3 Threatened flora state-listed species from within the area.
State listed Threatened fauna
State-listed Threatened fauna species recorded include small mammals such
as the Eastern Pygmy Possum, Southern Brown Bandicoot, Spotted-tailed
Quoll, Little and Eastern Bentwing Bat, Eastern Freetail Bat, Southern
Myotis, Grey-headed Flying Fox, greater Broad-nosed Bat and last but not
least the iconic Koala with one very recent sighting near Forestway (roadkill).
Threatened birds such as the Powerful Owl, Glossy Black Cockatoo, Black
Bittern, Varied Sittella, Scarlet Robin, the Eastern Osprey and Swift
Parrot, Threatened amphibians such as the Giant Burrowing Frog and the
Red-crowned Toadlet and the Rosenbergs Goanna, a Threatened reptile
which is a recurrent resident of the proposed park area.
State-listed Threatened flora
State-listed Threatened flora species include the Hairy Geebung, Camfields
Stringybark and Caleys Grevillea, which are confirmed from recent
sightings within the area. Other listed Threatened species which are known
to occur in the vicinity are the Black-eyed Susan, Netted Bottle Brush
and the Bauers Midge Orchid.
Locally Significant Native Species
Furthermore enigmatic and well-known marsupials as the Swamp Wallaby and
Short-beaked Echidnas are residents within the proposed area. Known populations
of Sugar Glider, Feather-tailed Glider both known to be susceptible
to habitat fragmentation - are breeding in the boundaries of the proposed
Locally significant bird species such as the Pheasant Coucal, Painted
Button Quail and the Rock Warbler are sharing the unique habitat of Red
Hill with the Brush Bronzewing, the Bar-shouldered Dove and the Tawny-crowned
Eastern Water Dragon
Puggle - juvenile echidna