#CreatureFeature – Eucalypt Woodlands of the WA Wheatbelt

For millennia, majestic eucalypt woodlands formed a patterned tapestry carpeting the region stretching across the southwest of WA, from Mullewa south to Cranbrook in the Great Southern.

These woodlands had adapted according to local and regional geology, climate and other environmental factors, and formed over sixty unique ecological community types, each with their own characteristic species composition and vegetative structure. Some have understoreys dominated by native grasses, others by shrubs and rocky outcrops. One thing they all share in common is the dominance of single-trunked eucalypt trees in the canopy, such as Salmon Gum or Wandoo. Many animals call these woodlands home, such as the woylies that dispersed quandong seeds, the tiger snakes that roam the lake shores and wetlands in search of frogs, the Carnaby’s cockatoos who raise their families in the hollows of old trees (Fig. 1), and the numbats that dart around the woody debris in pursuit of termites. The traditional owners of the regions possessing the woodlands, Noongar and Southern Yamatji Aboriginal people, hunted, gathered and farmed, and shared a spiritual connection with the woodlands and other species. Many culturally and spiritually-significant Aboriginal sites are found throughout the region, and many animals and plants are totems for people.

Figure 1: Carnaby’s cockatoos are an endangered species endemic to the south-west of WA, and breed in old hollow-bearing trees of the eucalypt woodlands. They are known as Ngoolark in Noongar language. (Image: Bush Heritage Australia)

However, after government-spurred clearing for broadacre agriculture in the 1960s, today only tiny, fragmented patches of these once majestic woodlands remain. These small remnants are often in poor health due to weed invasions and limited recruitment of young plants. Edge effects result in species utilising the smaller interior space of the habitat patch, effectively reducing the functional area. The introduction of feral cats and foxes has directly impacted on small native mammals through predation, and feral rabbits compete for food, erode the soil and limit seedling recruitment. Many of the species that once lived in the woodlands, such as the Greater Bilby and number, have become regionally extinct, and many more are threatened with it. Sadly, others, such as the broad-faced potoroo, have become extinct forever (Fig. 2). The loss of these species has resulted in flow-on effects, such as the decline of sandalwood populations and a loss of fungal dispersal. As a result, the Eucalypt Woodlands of the WA Wheatbelt are now Federally-listed by the EPBC Act 2016 as a critically-endangered Threatened Ecological Community (TEC). Whilst being Federally protected, there is minimal State legislation protecting these imperilled ecosystems.

Figure 2: The broad-faced potoroo is now extinct. (Image: John Gould, Mammals of Australia)

The remaining patches of these woodlands form an iconic aspect of sense of place for many WA Wheatbelt towns. The woodlands, despite being a last refuge for native wildlife, also provide invaluable environmental, economic, and social benefits to agriculture through their ecological services.

EnvironmentalEconomicSocial & Cultural
Shelter for livestock & troughs Temperature regulation for livestock and crops Maintenance of stable water table Maintained soil health and productivity Maintenance of healthy populations of insectivorous and predatory birds and bats that suppress agricultural pests Provision of native invertebrates for pollination services Regionally improving rainfall Provision of habitat for threatened, endemic and priority species and ecological communities   Increased lambing percentages and reduction in frost impacts Ameliorated financial impacts of salinification on crops Boost property value and sale price Increased wildflower tourism Diversification of income stream (e.g. farm stays, carbon farming, nature-based activities).    Areas for children and adults to explore and experience connection with nature Opportunities for children to learn about nature, animals, and adventure Sense of place Mental health benefits Improved amenity & aesthetics Sense of joy when wildlife present Recreation – horse riding, cycling, hiking, birdwatching  

There are countless benefits to improving the health and area of natural woodlands on your property, and there are many ways in which you can do so. By fencing remnant vegetation to exclude grazing pressures from livestock, feral herbivores and kangaroos, natural regeneration of the vegetation is encouraged. Regeneration is also enhanced by managing weeds through spraying, burning or methods like scalping. Managing feral predator and herbivore populations through baiting, shooting, and other methods of control further reduce the degree of stress experienced by highly-pressured populations of native species, enhancing their recovery and re-establishment of healthy populations within remnants. You can improve the ‘friendliness’ of your property to travelling wildlife by retaining and replenishing paddock trees, and planting or maintaining tree and understorey belts between paddocks and along fence lines. Planting native species within degraded remnants aids the recovery of the vegetation structure, creating habitat for species as well as improving the availability of food. Providing a year-round water supply, such as a water trough, helps keep animals watered, cool, and able to use inland breeding areas, particularly in the hot summer months. Installing nesting structures, such as Cockatubes, bat or phascogale boxes encourage these species to return to areas to rest, breed and feed.

Figure 3: Many people enjoy healthy eucalypt woodlands for recreational, spiritual, cultural, health and altruistic values. (Image: walkgps.com.au)

NACC has financial incentives available for land managers to implement these land practice changes to enhance the success of the endangered Carnaby’s black cockatoo in the Northern Agricultural Region. If you are interested, please contact NACC’s Biodiversity Project Officer, Kahree, on kahree.garnaut@nacc.com.au to discuss and determine your eligibility.

 Kahree Garnaut – Biodiversity Project Officer

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