As a volunteer of Werribee River Association, I had the opportunity to join Wyndham City Council in surveying native vegetation along the Werribee River between August 2024 and January 2025. The ongoing survey, conducted by Maarten Hulzebosch (Natural Asset Project Officer) aims to develop a comprehensive understanding of native vegetation within Wyndham City Council. It involves recording vegetation details such as GPS location, species name, maturity, and status indicating whether the specimen is remnant (naturally occurring) or planted. While the distinction between remnant and planted vegetation is evident in many areas due to features, location and topography, it is less clear in some places. The findings shed light on the current natural landscape in Wyndham City and provide key insights for future management. I assisted Maarten in surveying reserves along the Werribee River, contributing to the larger scope of work. The majority of my activity was spent at Tarneit Islands and the Cobbledicks Ford reserve, as these larger reserves contain many native species.
Vegetation along Werribee River (main image), Blackwood Wattle growing on a dead River Red Gum (left). Both images from Cobbledicks Ford Reserve.
The iconic River Red Gum (Eucalyptus camaldulensis) trees are a prominent feature of remnant native vegetation, with mature hollow-bearing specimens providing important habitat for local biodiversity. Some of the specimens observed indicate scars of cultural significance to the Wadawurrung and Bunurong people. Observations of mature remnant Werribee Blue Box (Eucalyptus baueriana subsp. thalassina) were less common, although younger planted specimens were frequent. Many wattle species occur frequently, such as Black Wattle (Acacia mearnsii), Blackwood Wattle (Acacia melonoxolyn), Wirilda (Acacia retinodes) and Lightwood Wattle (Acacia implexa). At Tarneit Islands, we observed remnant Bacchus Marsh Varnish Wattle (Acacia rostriformis) specimens, which are uncommon. Planted specimens of Hedge Wattle (Acacia paradoxa) were also observed along with planted specimens, or plants resulted from prior plantings of species such as Golden Wattle (Acacia pycnantha), a species indigenous to Werribee, but not along the Werribee River. We also observed planted species that are non-indigenous to the Werribee River such as Silver Wattle (Acacia dealbata).
Red rumped parrot in the backdrop of River red gum (left), Flowering Tree Violet(right). Both images from Riverbend Historical Park.
While wattle species dominated the midstory at most sites, Cobbledicks Ford Reserve featured a large community of Muttonwood (Myrsine variabilis, Myrsine howittiana) along the river, a species not commonly found in other areas. The riparian vegetation at multiple reserves had frequent observations of Woolly Tea-tree (Leptospermum lanigerum), though specimens of River Teatree Tea-tree (Leptospermum obovatum) were rare. River Bottlebrush (Callistemom siebeiri) and Tree Violet (Melicytus dentatus) were abundant throughout the survey. Planted specimens of Fragrant saltbush (Rhagodia parabolica) were widespread across reserves, where they often colonised and dominated the understory vegetation. In contrast, native Seaberry saltbush (Rhagodia candolleana) was less common, while a hybrid variety between the two Rhagodia species was more frequently observed. Remnant specimens of Rock Correa (Correa glabra) and Sweet Bursaria (Bursaria spinosa) were observed at Tarneit Islands, whereas remnant Native Elderberry (Sambucus australasica) was found at Cobbledicks Ford. While there were many planted specimens of Rock Correa and Sweet Bursaria, there were none for Native Elderberry.
Tiger snake, Tarneit Islands
The survey highlights an imbalance in the distribution of various native species along the Werribee River. The presence of remnant specimens of less common species underscores the importance of selecting these species for new plantings and future restoration projects to increase vegetation diversity, particularly in the understory. The detailed final account of species from this survey will provide invaluable data for analysing future directions in restoring and managing native ecosystems across Wyndham City Council. The riparian ecosystems along the Werribee River support rich biodiversity, with vegetation providing a critical foundation for various fauna. During the survey, numerous bird and reptile species were observed across the reserves, with the vegetation providing essential habitat structure. We look forward to the comprehensive report by Maarten Hulzebosch, which will offer expert insights into the management of native vegetation across Wyndham City Council.