John Oxley was the first explorer to venture into the Macquarie valley beyond Wellington. On the 12th June 1818 he reached the area now occupied by Dubbo and recorded in his journal that he had passed that day “over a very beautiful country, thinly wooded and apparently safe from the highest floods...”
The fertile soils of the grassy woodlands admired by Oxley, supported a highly diverse vegetation community. Grassy woodlands are categorised as open canopy forests because the trees are typically spread out and their canopies do not touch. They are dominated by eucalypts, typically boxes and red gums, with sparsely distributed shrubs, tussock grasses and herbs. Ephemeral grasses and herbs appear from seed banks following rain, and ground orchids and lilies produce a spectacular floral display following fires.
By 1840 the vast bulk of the river frontages and much of the adjoining country had been taken up by squatters. Initially grazing was concentrated upon the grassy woodlands because they needed little clearing.
The detrimental impact on the ecology was immediate and intensified when the availability of superphosphate and better agricultural machinery opened up the area to intensive wheat farming. By 1907 the country west of Wellington was described as “thickly occupied” by wheat farms.
Excessive clearing and continual cultivation resulted in serious soil erosion. Topsoils were stripped away by wind and rain, reducing productivity.
Less than one percent of the grassy woodlands admired by Oxley now remain. Some of them have been listed as endangered ecological communities under state and Commonwealth legislation in recognition of the need for greater protection, management and restoration.
The grassy woodland area forming part of the Biodiversity Garden in the Dubbo Regional Botanic Garden is an important education resource. Promoting understanding of the value of grassy woodlands and the impact of past farming practices will help inform and encourage future conservation.
By Ian McAlister & Karen Hagan