From Bush to Bitumen
A dense area of bush known as the Black Forest once covered the Unley region of the Adelaide Plains. The woodland forest was a mix of grey-box, blue gum, red gum, native pines and sheoak trees, with grass trees, native grasses and orchids.
These plants had deep roots that held the soil together and the plant debris that fell on the earth decomposed releasing nutrients into the soil.
This bush was home to the Kaurna people who moved with the seasons, relying on a deep knowledge of their land to find shelter, food and water. During autumn, extended family groups travelled inland from their summer camps along the coast, to the bush and the foothills. They knew the bush as wirra, and Willa willa was the name of the winding creeks lined with redgums.
When the Europeans arrived they brought with them the farming methods, animals and plants from their own countries. Many acres were sown with wheat and barley while other areas were fenced for grazing livestock. Orchards and vineyards were planted and olive oil, tobacco and jam produced.
With native bush cleared for farming, the habitat for native animals was greatly reduced. Native animals with soft padded feet were replaced with cows, sheep, pigs and horses that had hard hooves which broke the soil and caused erosion. Nutrients were not returned to the soil because crops were harvested or heavily grazed. Nutrients lost in this way were replaced by farm manure and chemical fertilizers. Tree clearing, ploughing and annual cropping exposed the soil and removed the soil-binding roots. This made the soil vulnerable to erosion.
As the increasing population demanded houses, farmland was sold and subdivided. By 1911, the population in Unley had reached 24,000 people who were living in over 5,000 dwellings. Buildings and roads gradually replaced paddocks during this period, removing much of the remaining native bush.
People were inspired to campaign to preserve trees and land for parks.
"Spare those trees! It would not cost a great deal to secure … a few allotments on which some of these kings of the old forest are growing: but it must be done soon or never."
The Register, 1911
Some native animals adapted to the increasing encroachment of the built environment, including possums and crested pigeons. Species that once fed on native plants began to scavenge in our parks and backyards. Other more vulnerable species were unable to adapt and have been lost from urban life.