Old Man Melvillei
Vegetation survey of
NPA/WWF Western Project Officer
|In a place where once there was abundant Old Man Saltbush, one now finds only very few surviving in old homestead paddocks protected from grazing pressure. And, from the woodland communities native to the area, it seems one finds only ‘old men’ remaining – old man melvillei and old man loderii – in small clumps of aging, almost senescent trees, where the natural understorey has been removed, and regeneration of overstorey species has been suppressed by continued grazing pressure.|
In early August, I joined a vegetation survey covering 100,000 ha, adjoining Mungo National Park to the north. Finding examples of Acacia melvillei and A. loderii woodland communities brought both excitement and sadness: excitement to locate a rare community in the field; sadness to witness their plight.
The condition of these acacia woodlands paints a graphic picture of the severe impact grazing has had on some vegetation communities in western NSW. The provision of artificial water in the landscape to sustain the pastoral industry has led to a vast increase in total grazing pressure (domestic stock, exotic and native herbivores) in these semi-arid landscapes. As a result, successful regeneration events in these communities are commonly suppressed, and the natural understorey is often highly degraded or absent. The woodlands of white cypress pine (Callitris glaucophylla) and belah/rosewood (Casuarina pauper/Alectryon oleifolius) show similar symptoms.
Many of the palatable shrubland species, such as saltbush (Atriplex spp) and bluebush (Maireana spp), that would once have dominated the lake bed Chenopod shrubland communities, have been replaced by exotics and more unpalatable shrubs, such as Nitraria spp and Schlerolaena spp. These changes can also be attributed to excessive grazing pressure.
Extensive areas of mallee were surveyed on the sand plains and dune systems. As these areas have not been developed for grazing by the provision of artificial water, they were in relatively good condition.
Land tenure and management issues
As part of the socio-economic package negotiated between NSW and the Commonwealth after the Willandra Lakes World Heritage Area was declared, the pastoral leases in this area were identified for purchase by the State. Their world heritage values (both cultural and natural) were deemed incompatible with continued use of the land for pastoral purposes. It was intended that certain areas of high cultural significance be transferred to the traditional Aboriginal people of the Willandra; other areas were earmarked for addition to the national parks estate, and may ultimately be returned to the traditional tribal groups.
The area surveyed forms part of this land. It represents a potential addition to Mungo NP which would almost quadruple its size; add another layer of protection to recognised world heritage values; and safeguard the natural biodiversity values, including the ‘old men,’ which have not been adequately protected under the management regime to date.
For a number of reasons, the land in question has not yet been transferred to the NPWS and remains in the management of the Department of Land and Water Conservation. Under this management regime, substantial areas continue to be sub-leased for grazing; artificial watering points remain. Removing domestic stock and closing off artificial water is fundamental to the recovery and long-term survival of these vegetation communities.
The NPA/WWF Western Project is working towards ensuring that this area is transferred to appropriate management and added to the national parks estate as soon as possible.
is the NPA/WWF Western Project Officer
and represents the Arid Lands Coalition on
the Willandra Lakes World Heritage Area Community Management Committee.
The area surveyed contains
vast deposits of valuable mineral sands (including zircon and rutile).
Current exploration activity is extensive. The effects of open-cut
mineral extraction, and the vast quantities of water required to
extract and process the minerals, mean that the development of this
industry will have a significant and adverse impact on land and water
More on this in a future issue.