From Craigieburn East Road south to Cooper Street, the land surrounding Merri Creek and incorporating the Craigieburn Grassland comprises a biosite of National significance.
The Craigieburn grassland covers an area of approximately 400 hectares between Craigieburn Road East and Cooper Street, although parts of the area have little or no significance including a quarry, house and improved pasture. The Craigieburn grassland has six key vegetation communities ranging from Plains Grassland to Danthonia Grassland and Stony Knoll Grassland. The site has been assigned National significance for flora due mainly to the presence of Carex tasmanica, Dianella amoena and Amphibromus pithogastris.
The Craigieburn habitat of Amphibromus pithogastris is likely to be critical habitat. This is also likely to be the case for Carex tasmanica. There are 10 State significant plant taxa and 114 regionally significant taxa at Craigieburn.
The Craigieburn Grassland has also been assigned National significance for fauna due to presence of Striped Legless Lizard and Plains-wanderer, . It also has three State significant species (Black Falcon, Red-Chested Button-quail and Freshwater Blackfish), as well as 27 regionally significant species. In relation to the Grassland Earless Dragon while it has not been recorded at the Craigieburn site, it may occur there, as relatively large areas of apparently suitable habitat are available. These include the bases of Stony Knolls, especially near the top of the Merri Creek escarpment. Given the extent of potentially suitable habitat, the site could prove to be one of the most important sites for this species in Victoria.
The critically endangered Golden Sun Moth (Synemon plana) was rediscovered in Craigieburn Grasslands in December 2003.
Merri Creek provides a key element of the Craigieburn site and the riparian and escarpment vegetation are of high quality. The creek corridor forms an important habitat link with sites such as Cooper Street to the south and Bald Hill to the north and is an especially important link for ground mammals. According to Beardsell, “the presence of the locally rare Common Wombat and Black Wallaby (not known from closer in along Merri Creek), suggests it acts as a faunal corridor” as pivotal to strategic habitat links between the Merri and Plenty systems.. He identified the Craigieburn Grassland
The Merri Creek through this reach contains fast-flowing riffle sections of basalt cobbles and tessellated pavement, slow-flowing open water, reedy pools and a shallow gorge with columnar basalt cliffs and boulder screes and escarpments. Future management of the stream frontage will need to take account of these values.
Beardsell described the Craigieburn Grassland and O’Herns Road Wetland as “the most extensive, intact, rare, diverse and significant volcanic plains rocky grassland, stream and wetland flora and fauna assemblage in Greater Melbourne. No biological reserve containing both of these systems is in existence”.
The Victorian Government purchased the bulk of the site in the late 1990’s and hearings into the Craigieburn Bypass eventually led to its construction mostly to the east of the grassland. Unfortunately freeway planning failed to provide satisfactory provision for habitat linkages to the north and east, so the potential for movements along these corridors for ground dwelling animals has been severely curtailed.
Issues relating to management of the site include:
·Control of weeds especially stipoid weeds,
·Biomass reduction by grazing needs to be managed to enhance the range of grassland values, including rare plants, stony knolls and riparian verges.