- SANDLETON
- South Australia
a look at the environment of Entwood
Entwood is situated in a semi-arid region of the Murraylands known as the Sandleton district. It lies approximately 24 kilometres west of Blanchetown on the Murray River.
Primary flora is comprised of Mallee eucalypt forest and open areas of saltbush and acacias. The landscape is gently undulating.
Average rainfall is 250mm (10 inches) per year.
Mallee trees are multi-stemmed Eucalypts; their name is derived from an aboriginal word, “mali” which means water. They have swollen underground lignotubers from which their multiple stems grow. Within these they store starches to assist the trees to survive periods of drought, excessive heat and even fire as well as housing new buds for trees to grow from.
often have hollow stems due to termites eating up through their heartwood. Provided their bark is intact, they remain healthy and thrive.These "old growth" mallee trees provide valuable habitat to native species (birds, bats, other mammals) after limbs fall and allow access to hollows. For example, two thirds of mallee bird species nest in hollows as opposed to cup nests.
there was an area of 11,000,000 hectares of Murray mallee. Only 15% of that remains today. Huge areas have been cleared for agriculture and firewood. During World War 2 (and petrol rationing) mallee forests were felled under government direction for charcoal production and fuelled gas converters on vehicles.
As they were not completely destroyed (Lignotubers were left) those mallee areas have slowly regrown stems and after decades are still not hollow and provide only limited shelter to wildlife. Stands of old growth mallee are therefore of high conservation value and Entwood is fortunate to contain considerable stands of these.
is not obvious and its importance is often overlooked. They play an important role in reducing wind and water erosion. They conserve moisture, are nitrogen fixers, enhance the nutritional status of soil and improve the survival of vascular plants.
Many human activities lead to the destruction of natural duricrust (vehicles, domestic grazing animals, ploughing). Areas set aside as Sanctuaries eventually see a return of duricrusts. Native animals, with their soft foot pads, only damage it over well used pathways but not extensively. Even in low rainfall areas, it recovers if undisturbed.
Clearly the following two images show the extent of the protection provided at Entwood, with no replanting or interference to the land occurring in over forty years, but apart from that:
As Entwood grew from many smaller allotments, it was riddled with internal fences (over 20 kilometres of them). Some of these were only 400 metres apart and were a source of difficulty and danger to migrating wildlife. Kangaroos and emus had been killed after being caught in them. All internal fences have now been removed from the Sanctuary.
After many years of agriculture and various landholders, the Sanctuary had large areas of weed species (especially in claypans where water tends to accumulate). This problem has been largely eradicated and reduced to a checking and cleanup operation.
