Mallee Restoration

DAMBUSTERS

For thousands of years there was no permanent water on Gluepot Reserve, and the plants and animals had evolved to cope with this sometimes harsh environment.  Then as recently as 60 years ago, a major development phase began and most of Gluepot’s 18 dams were dug just before World War II to provide water for sheep.  The provision of permanent water meant that some parts of the property were overgrazed and the soil was damaged during droughts, particularly those areas within 2 km of these artificial water points.  However, a recent CSIRO study (Landsberg et al 1997) shows that the impacts of grazing can be recorded 8 km or more from dams.  Overgrazing was not just by sheep, but feral goats and elevated numbers of kangaroos contributed too.  Melbourne University research shows that each of these herbivores target different plant groups in the mallee.

Total grazing pressure is recognised by managers of mallee reserves as one of the key threats to native plants and animals.  With the removal of sheep from Gluepot Reserve in 1996 there has been a reduction in total grazing pressure and palatable species such as pearl bluebush are rapidly regenerating and new growth is very noticeable. An active Feral & Pest Animal Management Program has ensured that goat numbers have been kept to a minimum, and since the closure of the last accessible dam, goats are infrequently seen.

Landsberg et al (1997) strongly recommended that a staged program of strategic closure of artificial water sources in conservation reserves in the Rangelands be undertaken, in recognition of the small proportion of pastoral lands remaining outside the influence of water, and the damage to biodiversity stemming from the widespread provision of water.  In recent years decommissioning of water points in mallee parks has taken place at Tarawi Nature Reserve in NSW and Murray Sunset National Park in Victoria.  Melbourne University research indicates that this should have no negative impacts on threatened species.

During 1999 -2001, Gluepot Reserve supported a PhD study on the impact of dams on the Reserve’s vegetation and avifauna.  At the same time, a comprehensive flora and fauna monitoring program was devised and implemented.

Gluepot Reserve received Natural Heritage Trust funding to decommission all but two dams to assist the conservation of the endangered Black-eared Miner.  Black-eared Miners do not need artificial water sources and are threatened by hybridisation with Yellow-throated Miners.

Fourteen dams were closed on Gluepot in 1999-2001- the remaining two dams were closed in 2002.  Five 90,000 litre concrete tanks that are maintained for fire fighting have been roofed to collect rainwater, as happens on the Nullabour Plain. Elevated drinking troughs for birds have been installed off all five tanks and elevated hides for birdwatchers have been built overlooking these troughs. These hides are much more attractive venues for birdwatching than the old barren dam sites, and elevated drinking troughs make it harder for feral cats and foxes to hunt successfully there. Further poly tanks for fire fighting have been situated on the Oil Road Dam site and at the eastern end of the Oil Road.

The two dams at the homestead have been retained, and have been fenced off to control herbivore access. Water from these dams is used to supply Whistler Tank and the large tank at the homestead (toilet and Met. Bureau use).  All of this work is guided by the monitoring program and the outcomes of the PhD study.

Following  closure of the 16 dams and their subsequent revegetation, goat numbers are now relatively insignificant and kangaroo numbers have fallen to ‘natural’ pre-dam levels.                                                                       Dam Closure Dates