Native vegetation at Kooragang Wetlands includes mangroves,
saltmarsh, freshwater wetlands, riverbank or riparian vegetation and
floodplain rainforest. The aim of the revegetation has been to
restore the rich biodiversity the area once had and to protect
threatened species. Weed removal and control of feral animals such
as rabbits and hares are a necessary part of restoring native
vegetation but will be discussed in the manage
pests section.
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Saltmarsh and mangroves
form the intertidal vegetation. |
Freshwater wetlands form
in low- lying areas not effected by tides. |
These casuarinas are typical trees that
grow along the banks of the Hunter River. |
A strangler fig found in
one of the rainforest
remnants on Ash Island. |
intertidal vegetation
Mangroves and saltmarsh species have a large existing source of seed
at Kooragang Wetlands. Thus we don't need to plant these by
hand. We only have to manage the frequency and
salinity of water flowing in an area, to determine whether the
mangroves, saltmarsh or non-tidal vegetation grows in an area. (See `managing water flows’
section)
We have altered water flows and ground levels to restore vegetation
in some low-lying areas. We have also restricted cattle and vehicle
access to these areas by use of bollards and appropriate fencing.
This has greatly improved the health of mangroves and saltmarsh
alike.
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Before:
Cattle roamed these saltmarsh and mangrove areas prior to
1993, degrading this vital habitat. |
After: These
young mangroves are able to grow now that cattle have been
removed from the riverbanks. |
Before: Intertidal areas degraded by
uncontrolled grazing. |
After: Saltmarsh
recovered strongly once cattle were kept out by fencing. |
freshwater wetlands
Some low-lying freshwater areas are natural and some result from
human actions such as road building. Where necessary, fencing and
bollards have been used to protect freshwater wetland areas from
cattle and vehicles.
Other isolated low lying areas have been created to provide more
habitat options for threatened species such as the endangered Green
and Golden Bell Frog (see threatened
species section). When the low-lying area is close to other
freshwater wetland areas, it readily self-seeds with freshwater
plants such as Water Couch and Water
Ribbon.
If the created freshwater pond is far from a natural freshwater
plant seed source
or if rapid vegetation cover is required, then the area is planted
out by hand using indigenous water plants.
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Fencing
keeps cattle out of freshwater wetland areas such as in this
foreground |
Some excavated ponds are
planted with sedges and other water plants for quick results. |
Before: A pond created from a
difficult to maintain low area. Photo:2001. |
After: The same
pond two years later. Six frog species are regularly
heard here. |
Riparian vegetation
Natural vegetation that grew along the river banks of the lower
Hunter includes casuarinas, melaleucas and bottlebrushes. Much of
it has disappeared due to clearing and uncontrolled grazing. Restoring
the vegetation along the riverbanks increases the biodiversity of
the area as well as providing shade and wind protection and helping
to stabilise the banks
To restore vegetation along our riverbanks, we first built permanent
fencing at a distance of 50 metres from the river. This stops cattle
from eating the vegetation and damaging the riverbanks. In this
protected area we have planted indigenous riparian trees and shrubs.
In one area where the bank erosion was particularly bad we
trialled
planting long stem casuarinas (casuarinas specially grown with
roots coming out from about one metres of their stem - the casuarina
is then planted one metre into the soil.
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Before: Cattle
have full access to the river resulting in increased erosion
and little plant protection. |
Students lend a hand to
revegetate the riverbank in 1998 after fencing stopped cattle
access to the river. |
After: Some of the trees and shrubs
planted along the north arm of the Hunter River.(1998) |
After: The same
area from the air, seven years on. |
Rainforest
Very little of the lush rainforest that once grew on Ash Island
remained in 1993. Only half of the species recorded in 1862 remained.
Those that had survived remained as individual paddock trees or
as very small remnants, a number of which contained the endangered
rainforest vine, White Cynanchum (Cynanchum elegans).
Where possible, seed from existing plants was collected and propagated.
For species that no longer existed on site, seed was collected from
the surrounding floodplain. To date we have been able to propagate
just over half of some 170 rainforest species on the historical
list.
Since 1996 we have been regenerating the rainforest remnants, linking
and further extending them to create more secure habitat for White
Cynanchum and other wildlife that depends on lowland floodplain
rainforest.
Areas to be revegetated are first fenced if necessary to exclude
cattle. Problem introduced species such as lantana are removed and
a shelter belt of fast growing, wind-screening trees and shrubs
planted around the perimeter.
Planting is done by training teams such as Green Corps, staff and
volunteers. To date more the 120,000 trees and shrubs have been
planted in several hectares to create lowland floodplain rainforest,
woodland and riparian corridors.
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Before: Isolated
remnants were all that remained in 1993 of `lush' rainforest
of 150 years before. |
Several plants of White
Cynanchum, an endangered vine of rainforest margins, survive
on Ash Island. |
A Green Corps team helps extend rainforest
remnants to form viable corridors. |
After: Bare
paddocks have been turned into forest. Photo: 2003 |
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