Communities and habitat

Healthy functioning ecosystems are a fundamental element of healthy functioning landscapes. They are valuable in themselves and provide ecosystem services such as air and water quality; carbon sequestration; and habitat, amenity and cultural values. Biodiversity is an important part of ecosystem functioning and any further losses are unacceptable for future generations.

A major threat to lowland grassland and woodland communities is from the continued spread of urban development, particularly for housing. This threat is exacerbated by the strong economic position of the ACT as people continue to prefer large houses on separate blocks of land either in the ACT or in neighbouring NSW.

Demand for housing is also being driven by a growing population and a declining number of people per household so that the rate that new households are formed is increasing. From a perspective of controlling the consumption of raw land, housing demand must take denser forms and include more redevelopment of existing housing.

Weeds are also of concern to both biodiversity and agricultural values particularly following the 2000 to 2006 drought and 2003 bushfires. Weeds such as Pattersons curse, capeweed and nodding thistle have become established on the newly bare ground that has followed loss of introduced pasture and native plants through fire and drought. Other weeds (e.g. Chilean needle grass [Nasella neesiana] and African love grass [Eragrostis curvula]) are also spreading in any places where the land has been disturbed particularly along fire trails, utility easements and adjacent to urban areas. Other weeds include willow, broom and some water weeds.

Pests such as oriental weatherloach (Misgurnus anguillicaudatus) and European wasp (Vespula germanica) are increasing their hold in urban and other areas, although recent data compiled by Canberra Ornithologists Group indicate that the common myna (Acridotheres tristis) may be decreasing in abundance in the urban areas of Canberra (Canberra Ornithologists Group 2008). Feral horses have migrated from the Snowy Mountains into the ACT following the bushfires and removal of dense vegetation.

Natural values along with urban areas need to be protected from bushfires. Key areas for protection have been identified and appropriate management for biodiversity outcomes is being
implemented.

Recent positive moves to limit threats to biodiversity have included:

• reducing (but not eliminating) land development in relatively undisturbed woodlands and grassland areas by increasing the rate of urban infill in areas that are already degraded, redeveloping burnt pine plantations and moving to a smaller block size in new developments
• changing the location of Gungahlin town centre to reduce threats to habitats of threatened species
• developing land management agreements that enable farmers and biodiversity specialists to work together in rural areas and
• increasing the area protected by nature reserves.